[Title 40 CFR 136]
[Code of Federal Regulations (annual edition) - July 1, 1996 Edition]
[Title 40 - PROTECTION OF ENVIRONMENT]
[Chapter I - ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)]
[Part 136 - GUIDELINES ESTABLISHING TEST PROCEDURES FOR THE ANALYSIS OF POLLUTANTS]
[From the U.S. Government Publishing Office]




  40
  PROTECTION OF ENVIRONMENT
  10
  1996-07-01
  1996-07-01
  false
  GUIDELINES ESTABLISHING TEST PROCEDURES FOR THE ANALYSIS OF POLLUTANTS
  136
  PART 136
  
    PROTECTION OF ENVIRONMENT
    ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)
  


PART 136--GUIDELINES ESTABLISHING TEST PROCEDURES FOR THE ANALYSIS OF POLLUTANTS--Table of Contents




Sec.
136.1  Applicability.
136.2  Definitions.
136.3  Identification of test procedures.
136.4  Application for alternate test procedures.
136.5  Approval of alternate test procedures.

Appendix A to Part 136--Methods for Organic Chemical Analysis of 
          Municipal and Industrial Wastewater
Appendix B to Part 136--Definition and Procedure for the Determination 
          of the Method Detection Limit--Revision 1.11
Appendix C to Part 136--Inductively Coupled Plasma--Atomic Emission 
          Spectrometric Method for Trace Element Analysis of Water and 
          Wastes Method 200.7
Appendix D to Part 136--Precision and Recovery Statements for Methods 
          for Measuring Metals

    Authority: Secs. 301, 304(h), 307 and 501(a), Pub. L. 95-217, 91 
Stat. 1566, et seq. (33 U.S.C. 1251, et seq.) (the Federal Water 
Pollution Control Act Amendments of 1972 as amended by the Clean Water 
Act of 1977).



Sec. 136.1   Applicability.

    The procedures prescribed herein shall, except as noted in 
Sec. 136.5, be used to perform the measurements indicated whenever the 
waste constituent specified is required to be measured for:
    (a) An application submitted to the Administrator, or to a State 
having an approved NPDES program for a permit under section 402 of the 
Clean Water Act of 1977, as amended (CWA), and/or to reports required to 
be submitted under NPDES permits or other requests for quantitative or 
qualitative effluent data under parts 122 to 125 of Title 40, and,
    (b) Reports required to be submitted by discharges under the NPDES 
established by parts 124 and 125 of this chapter, and,
    (c) Certifications issued by States pursuant to section 401 of the 
CWA, as amended.

[38 FR 28758, Oct. 16, 1973, as amended at 49 FR 43250, Oct. 26, 1984]



Sec. 136.2   Definitions.

    As used in this part, the term:
    (a) Act means the Clean Water Act of 1977, Pub. L. 95-217, 91 Stat. 
1566, et seq. (33 U.S.C. 1251 et seq.) (The Federal Water Pollution 
Control Act Amendments of 1972 as amended by the Clean Water Act of 
1977).
    (b) Administrator means the Administrator of the U.S. Environmental 
Protection Agency.
    (c) Regional Administrator means one of the EPA Regional 
Administrators.
    (d) Director means the Director of the State Agency authorized to 
carry out an approved National Pollutant Discharge Elimination System 
Program under section 402 of the Act.
    (e) National Pollutant Discharge Elimination System (NPDES) means 
the national system for the issuance of permits under section 402 of the 
Act and includes any State or interstate program which has been approved 
by the Administrator, in whole or in part, pursuant to section 402 of 
the Act.
    (f) Detection limit means the minimum concentration of an analyte 
(substance) that can be measured and reported with a 99% confidence that 
the analyte concentration is greater than zero as determined by the 
procedure set forth at appendix B of this part.

[38 FR 28758, Oct. 16, 1973, as amended at 49 FR 43250, Oct. 26, 1984]



Sec. 136.3  Identification of test procedures.

    (a) Parameters or pollutants, for which methods are approved, are 
listed together with test procedure descriptions and references in 
Tables IA, IB, IC, ID, and IE. The full text of the referenced test 
procedures are incorporated by reference into Tables IA, IB, IC, ID, and 
IE. The references and the sources from which they are available are 
given in paragraph (b) of this section. These test procedures are 
incorporated as they exist on the day of approval and a notice of any 
change in these test procedures will be published in the Federal 
Register. The discharge parameter values for which reports are required 
must be determined by one of the standard analytical test procedures 
incorporated by reference and described in Tables IA, IB, IC, ID, and 
IE, or by any alternate test procedure which has been approved by the 
Administrator under the provisions of

[[Page 6]]

paragraph (d) of this section and Secs. 136.4 and 136.5 of this part 
136. Under certain circumstances (Sec. 136.3 (b) or (c) or 40 CFR 
401.13) other test procedures may be used that may be more advantageous 
when such other test procedures have been previously approved by the 
Regional Administrator of the Region in which the discharge will occur, 
and providing the Director of the State in which such discharge will 
occur does not object to the use of such alternate test procedure.

[[Page 7]]



                                                     Table IA.--List of Approved Biological Methods                                                     
--------------------------------------------------------------------------------------------------------------------------------------------------------
        Parameter and units                 Method \1\                    EPA            Standard methods, 18th Ed.      ASTM              USGS         
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bacteria:                                                                                                                                               
    1. Coliform (fecal), number     Most Probable Number        p. 132 \3\              9221C E \4\                  ...........  ......................
     per 100 mL.                     (MPN), 5 tube.             p. 124 \3\              9222D \4\                                 B-0050-85 \5\         
                                    3 dilution, or Membrane                                                                                             
                                     filter (MF) \2\, single                                                                                            
                                     step.                                                                                                              
    2. Coliform (fecal) in          MPN, 5 tube, 3 dilution,    p. 132 \3\              9221C E \4\                  ...........  ......................
     presence of chlorine, number    or.                        p. 124 \3\              9222D \4\                                                       
     per 100 mL.                    MF, single step \6\.......                                                                                          
    3. Coliform (total), number     MPN, 5 tube, 3 dilution,    p. 114 \3\              9221B \4\                    ...........  ......................
     per 100 mL.                     or.                        p. 108 \3\              9222B \4\                                 B-0025-85 \5\         
                                    MF \2\ single step or two                                                                                           
                                     step.                                                                                                              
    4. Coliform (total), in         MPN, 5 tube, 3 dilution,    p. 114 \3\              9221B \4\                    ...........  ......................
     presence of chlorine, number    or.                        p. 111 \3\              9222(B+B.5c) \4\                                                
     per 100 mL.                    MF \2\ with enrichment....                                                                                          
    5. Fecal streptococci, number   MPN, 5 tube, 3 dilution...  p. 139 \3\              9230B \4\                    ...........  ......................
     per 100 mL.                    MF \2\, or................  p. 136 \3\              9230C \4\                                 B-0055-85 \5\         
                                    Plate count...............  p. 143 \3\                                                                              
Aquatic Toxicity:                                                                                                                                       
    6. Toxicity, acute, fresh       Daphnia, Ceriodaphnia,      Sec. 9 \7\              ...........................  ...........  ......................
     water organisms, LC50,          Fathead Minnow, Rainbow                                                                                            
     percent effluent.               Trout, Brook Trout, or                                                                                             
                                     Bannerfish Shiner                                                                                                  
                                     mortality.                                                                                                         
    7. Toxicity, acute, estuarine   Mysid, Sheepshead Minnow,   Sec. 9 \7\              ...........................  ...........  ......................
     and marine organisms, LC50,     or Menidia spp. mortality.                                                                                         
     percent effluent.                                                                                                                                  
    8. Toxicity, chronic, fresh     Fathead minnow larval       1000.0 \8\              ...........................  ...........  ......................
     water organisms, NOEC or        survival and growth.       1001.0 \8\              ...........................                                     
     IC25, percent effluent.        Fathead minnow embryo-                              ...........................                                     
                                     larval survival and        1002.0 \8\              ...........................                                     
                                     teratogenicity.            1003.0 \8\              ...........................                                     
                                    Ceriodaphnia survival and                                                                                           
                                     reproduction.                                                                                                      
                                    Selenastrum growth........                                                                                          
    9. Toxicity, chronic,           Sheepshead minnow larval    1004.0 \9\              ...........................  ...........  ......................
     estuarine and marine            survival and growth.       1005.0 \9\              ...........................                                     
     organisms, NOEC or IC25,       Sheepshead minnow embryo-                                                                                           
     percent effluent.               larval survival and        1006.0 \9\              ...........................                                     
                                     teratogenicity.            1007.0 \9\                                                                              
                                    Menidia beryllina larval    1008.0 \9\              ...........................                                     
                                     and growth.                1009.0 \9\              ...........................                                     
                                    Mysidopsis bahia survival,                                                                                          
                                     growth, and fecundity.                                                                                             
                                    Arbacia punctulata                                                                                                  
                                     fertilization.                                                                                                     
                                    Champia parvula                                                                                                     
                                     reproduction.                                                                                                      
--------------------------------------------------------------------------------------------------------------------------------------------------------
Notes to Table IA:                                                                                                                                      
\1\ The method must be specified when results are reported.                                                                                             
\2\ A 0.45 um membrane filter (MF) or other pore size certified by the manufacturer to fully retain organisms to be cultivated and to be free of        
  extractables which could interfere with their growth.                                                                                                 
\3\ USEPA. 1978. Microbiological Methods for Monitoring the Environment, Water, and Wastes. Environmental Monitoring and Support Laboratory, U.S.       
  Environmental Protection Agency, Cincinnati, Ohio. EPA/600/8-78/017.                                                                                  
\4\ APHA. 1992. Standard Methods for the Examination of Water and Wastewater. American Public Health Association. 18th Edition. Amer. Publ. Hlth.       
  Assoc., Washington, DC.                                                                                                                               
\5\ USGS. 1989. U.S. Geological Survey Techniques of Water-Resources Investigations, Book 5, Laboratory Analysis, Chapter A4, Methods for Collection and
  Analysis of Aquatic Biological and Microbiological Samples, U.S. Geological Survey, U.S. Department of Interior, Reston, Virginia.                    
\6\ Because the MF technique usually yields low and variable recovery from chlorinated wastewaters, the Most Probable Number method will be required to 
  resolve any controversies.                                                                                                                            
\7\ USEPA. 1993. Methods for Measuring the Acute Toxicity of Effluents to Freshwater and Marine Organisms. Fourth Edition. Environmental Monitoring     
  Systems Laboratory, U.S. Environmental Protection Agency, Cincinnati, Ohio. August 1993, EPA/600/4-90/027F.                                           

[[Page 8]]

                                                                                                                                                        
\8\ USEPA. 1994. Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Third Edition.       
  Environmental Monitoring Systems Laboratory, U.S. Environmental Protection Agency USEPA. 1994, Cincinnati, Ohio (July 1994, EPA/600/4-91/002).        
\9\ Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Marine and Estuarine Organisms. Second Edition.         
  Environmental Monitoring Systems Laboratory, U.S. Environmental Protection Agency, Cincinnati, Ohio (July 1994, EPA/600/4-91/003). These methods do   
  not apply to marine waters of the Pacific Ocean.                                                                                                      


                                                  Table IB.--List of Approved Inorganic Test Procedures                                                 
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                            Reference (method number or page)                                           
  Parameter, units and method  -------------------------------------------------------------------------------------------------------------------------
                                  EPA 1,35      STD methods  18th ed.                 ASTM                       USGS \2\                  Other        
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. Acidity, as CaCO3, mg/L:                                                                                                                             
    Electrometric endpoint or         305.1  2310 B(4a)................  D1067-92                                                                       
     phenolphthalein endpoint.                                                                                                                          
2. Alkalinity, as CaCO3, mg/L:                                                                                                                          
    Electrometric or                  310.1  2320 B....................  D1067-92.....................  I-1030-85................  973.43.\3\           
     Colorimetric titration to        310.2  ..........................  .............................  I-2030-85                                       
     pH 4.5, manual or                                                                                                                                  
     automated.                                                                                                                                         
3. Aluminum--Total,\4\ mg/L;                                                                                                                            
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration \36\.        202.1  3111 D....................  .............................  I-3051-85                                       
    AA furnace................        202.2  3113 B                                                                                                     
    Inductively Coupled Plasma/   \5\ 200.7  3120 B                                                                                                     
     Atomic Emission                                                                                                                                    
     Spectrometry (ICP/AES)                                                                                                                             
     \36\.                                                                                                                                              
    Direct Current Plasma       ...........  ..........................  D4190-82(88).................  .........................  Note 34.             
     (DCP) \36\.                                                                                                                                        
    Colorimetric (Eriochrome    ...........  3500-Al D                                                                                                  
     cyanine R).                                                                                                                                        
4. Ammonia (as N), mg/L:                                                                                                                                
    Manual, distillation (at          350.2  4500-NH3 B................  .............................  .........................  973.49.\3\           
     pH 9.5),\6\ followed by.                                                                                                                           
    Nesslerization............        350.2  4500-NH3 C................  D1426-93(A)..................  I-3520-85................  973.49.\3\           
    Titration.................        350.2  4500-NH3 E                                                                                                 
    Electrode.................        350.3  4500-NH3 F or G...........  D1426-93(B)                                                                    
    Automated phenate, or.....        350.1  4500-NH3 H................  .............................  I-4523-85                                       
    Automated electrode.......  ...........  ..........................  .............................  .........................  Note 7.              
5. Antimony-Total,\4\ mg/L;                                                                                                                             
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration \36\.        204.1  3111 B                                                                                                     
    AA furnace................        204.2  3113 B                                                                                                     
    ICP/AES \36\..............    \5\ 200.7  3120 B                                                                                                     
6. Arsenic-Total,\4\ mg/L:                                                                                                                              
    Digestion \4\ followed by.        206.5                                                                                                             
        AA gaseous hydride....        206.3  3114 B 4.d................  D2972-93(B)..................  I-3062-85                                       
        AA furnace............        206.2  3113 B....................  D2972-93(C)                                                                    
        ICP/AES,\36\ or.......    \5\ 200.7  3120 B                                                                                                     
        Colorimetric (SDDC)...        206.4  3500-As C.................  D2972-93(A)..................  I-3060-85                                       
7. Barium--Total,\4\ mg/L;                                                                                                                              
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration \36\.        208.1  3111 D....................  .............................  I-3084-85                                       
    AA furnace................        208.2  3113 B....................  D4382-91                                                                       
    ICP/AES \36\..............    \5\ 200.7  3120 B                                                                                                     
    DCP \36\..................  ...........  ..........................  .............................  .........................  Note 34.             
8. Beryllium--Total,\4\ mg/L;                                                                                                                           
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration......        210.1  3111 D....................  D3645-93(88)(A)..............  I-3095-85                                       
    AA furnace................        210.2  3113 B....................  D3645-93(88)(B)                                                                
    ICP/AES...................    \5\ 200.7  3120 B                                                                                                     
    DCP, or...................  ...........  ..........................  D4190-82(88).................  .........................  Note 34.             

[[Page 9]]

                                                                                                                                                        
    Colorimetric (aluminon)...  ...........  3500-Be D                                                                                                  
9. Biochemical oxygen demand                                                                                                                            
 (BOD5), mg/L:                                                                                                                                          
    Dissolved Oxygen Depletion        405.1  5210 B....................  .............................  I-1578-78 \8\............  973.44,\3\ p. 17.\9\ 
10. Boron \37\--Total, mg/L:                                                                                                                            
    Colorimetric (curcumin)...        212.3  4500-B B..................  .............................  I-3112-85                                       
    ICP/AES, or...............    \5\ 200.7  3120 B                                                                                                     
    DCP.......................  ...........  ..........................  D4190-82(88).................  .........................  Note 34              
11. Bromide, mg/L:                                                                                                                                      
    Titrimetric...............        320.1  ..........................  D1246-82(88)(C)..............  I-1125-85................  p. S44.\10\          
12. Cadmium--Total,\4\ mg/L;                                                                                                                            
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration \36\.        213.1  3111 B or C...............  D3557-90(A or B).............  I-3135-85 or I-3136-85...  974.27,\3\ p. 37.\9\ 
    AA furnace................        213.2  3113 B....................  D3557-90(D)                                                                    
    ICP/AES \36\..............    \5\ 200.7  3120 B....................  .............................  I-1472-85                                       
    DCP \36\..................  ...........  ..........................  D4190-82(88).................  .........................  Note 34.             
    Voltametry,\11\ or........  ...........  ..........................  D3557-90(C)                                                                    
    Colorimetric (Dithizone)..  ...........  3500-Cd D                                                                                                  
13. Calcium--Total,\4\ mg/L;                                                                                                                            
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration......        215.1  3111 B....................  D511-93(B)...................  I-3152-85                                       
    ICP/AES...................    \5\ 200.7  3120 B                                                                                                     
    DCP, or...................  ...........  ..........................  .............................  .........................  Note 34.             
    Titrimetric (EDTA)........        215.2  3500-Ca D.................  D511-93(A)                                                                     
14. Carbonaceous biochemical                                                                                                                            
 oxygen demand (CBOD5), mg/L                                                                                                                            
 \12\:                                                                                                                                                  
    Dissolved Oxygen Depletion  ...........  5210 B                                                                                                     
     with nitrification                                                                                                                                 
     inhibitor.                                                                                                                                         
15. Chemical oxygen demand            410.1  5220 C....................  D1252-88(A)..................  I-3560-85................  973.46,\3\ p. 17.\9\ 
 (COD), mg/L; Titrimetric, or.        410.2  ..........................  .............................  I-3562-85................                       
                                      410.3                                                                                                             
    Spectrophotometric, manual        410.4  5220 D....................  D1252-88(B)..................  I-3561-85................  Notes 13 or 14.      
     or automated.                                                                                                                                      
16. Chloride, mg/L:                                                                                                                                     
    Titrimetric (silver         ...........  4500-Cl- B................  D512-89(B)...................  I-1183-85                                       
     nitrate) or.                                                                                                                                       
    (Mercuric nitrate)........        325.3  4500-Cl- C................  D512-89(A)...................  I-1184-85................  973.51.\3\           
    Colorimetric, manual or...  ...........  ..........................  .............................  I-1187-85                                       
    Automated (Ferricyanide)..     325.1 or  4500-Cl- E................  .............................  I-2187-85                                       
                                      325.2                                                                                                             
17. Chlorine--Total residual,                                                                                                                           
 mg/L; Titrimetric:                                                                                                                                     
    Amperometric direct.......        330.1  4500-Cl D.................  D1253-86(92)                                                                   
    Iodometric direct.........        330.3  4500-Cl B                                                                                                  
    Back titration ether end-         330.2  4500-Cl C                                                                                                  
     point \15\ or.                                                                                                                                     
    DPD-FAS...................        330.4  4500-Cl F                                                                                                  
    Spectrophotometric, DPD...        330.5  4500-Cl G                                                                                                  
    Or Electrode..............  ...........  ..........................  .............................  .........................  Note 16.             
18. Chromium VI dissolved, mg/                                                                                                                          
 L; 0.45 micron filtration                                                                                                                              
 followed by:                                                                                                                                           
    AA chelation-extraction or        218.4  3111 C....................  .............................  I-1232-85                                       
    Colorimetric                ...........  3500-Cr D.................  D1687-92(A)..................  I-1230-85                                       
     (Diphenylcarbazide).                                                                                                                               
19. Chromium--Total,\4\ mg/L;                                                                                                                           
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration \36\.        218.1  3111 B....................  D1687-92(B)..................  I-3236-85................  974.27.\3\           
    AA chelation-extraction...        218.3  3111 C                                                                                                     
    AA furnace................        218.2  3113 B....................  D1687-92(C)                                                                    

[[Page 10]]

                                                                                                                                                        
    ICP/AES \36\..............    \5\ 200.7  3120 B                                                                                                     
    DCP,\36\ or...............  ...........  ..........................  D4190-82(88).................  .........................  Note 34.             
    Colorimetric                ...........  3500-Cr D                                                                                                  
     (Diphenylcarbazide)                                                                                                                                
20. Cobalt--Total,\4\ mg/L;                                                                                                                             
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration......        219.1  3111 B or C...............  D3558-90(A or B).............  I-3239-85................  p. 37.\9\            
    AA furnace................        219.2  3113 B....................  D3558-90(C)                                                                    
    ICP/AES...................    \5\ 200.7  3120 B                                                                                                     
    DCP.......................  ...........  ..........................  D4190-82(88).................  .........................  Note 34.             
21. Color platinum cobalt                                                                                                                               
 units or dominant wavelength,                                                                                                                          
 hue, luminance purity:                                                                                                                                 
    Colorimetric (ADMI), or...        110.1  2120 E....................  .............................  .........................  Note 18.             
    (Platinum cobalt), or.....        110.2  2120 B....................  .............................  I-1250-85................  .....................
    Spectrophotometric........        110.3  2120 C                                                                                                     
22. Copper--Total,4 mg/L;                                                                                                                               
 Digestion 4 followed by:                                                                                                                               
    AA direct aspiration 36...        220.1  3111 B or C...............  D1688-90(A or B).............  I-3270-85 or I3271-85....  974.27 3 p. 37.9     
    AA furnace................        220.2  3113 B....................  D1688-90(C)                                                                    
    ICP/AES 36................      5 200.7  3120 B                                                                                                     
    DCP 36 or.................  ...........  ..........................  D4190-82(88).................  .........................  Note 34.             
    Colorimetric (Neocuproine)  ...........  3500-Cu D                                                                                                  
     or.                                                                                                                                                
    (Bicinchoninate)..........  ...........  Or E......................  .............................  .........................  Note 19.             
23. Cyanide--Total, mg/L:                                                                                                                               
    Manual distillation with    ...........  4500-CN C.................  D2036-91(A)                                                                    
     MgCl2 followed by.                                                                                                                                 
    Titrimetric, or...........  ...........  4500-CN D.................  .............................  .........................  p. 22.9              
    Spectrophotometric, manual     31 335.2  4500-CN E.................  D2036-91(A)..................  I-3300-85                                       
     or.                                                                                                                                                
    Automated 20..............     31 335.3                                                                                                             
24. Cyanide amenable to                                                                                                                                 
 chlorination,mg/L:                                                                                                                                     
    Manual distillation with          335.1  4500-CN G.................  D2036-91(B)                                                                    
     MgCl2 followed by                                                                                                                                  
     titrimetric or                                                                                                                                     
     Spectrophotometric.                                                                                                                                
25. Fluoride--Total, mg/L:                                                                                                                              
    Manual distillation 6       ...........  4500-F B                                                                                                   
     followed by.                                                                                                                                       
    Electrode, manual or......        340.2  4500-F C..................  D1179-93(B)                                                                    
    Automated.................  ...........  ..........................  .............................  I-4327-85                                       
    Colorimetric (SPADNS).....        340.1  4500-F D..................  D1179-93(A)                                                                    
    Or Automated complexone...        340.3  4500-F E                                                                                                   
26. Gold--Total,4 mg/L;                                                                                                                                 
 Digestion 4 followed by:                                                                                                                               
    AA direct aspiration......        231.1  3111 B                                                                                                     
    AA furnace, or............        231.2                                                                                                             
    DCP.......................  ...........  ..........................  .............................  .........................  Note 34.             
27. Hardness--Total, as CaCO3,                                                                                                                          
 mg/L                                                                                                                                                   
    Automated colorimetric,...        130.1                                                                                                             
    Titrimetric (EDTA), or Ca         130.2  2340 B or C...............  D1126-86(92).................  I-1338-85................  973.52B.3            
     plus Mg as their                                                                                                                                   
     carbonates, by                                                                                                                                     
     inductively coupled                                                                                                                                
     plasma or AA direct                                                                                                                                
     aspiration. (See                                                                                                                                   
     Parameters 13 and 33).                                                                                                                             
28. Hydrogen ion (pH), pH                                                                                                                               
 units                                                                                                                                                  

[[Page 11]]

                                                                                                                                                        
    Electrometric measurement,        150.1  4500-H+ B.................  D1293-84(90)(A or B).........  I-1586-85................  973.41.3             
     or.                                                                                                                                                
    Automated electrode.......  ...........  ..........................  .............................  .........................  Note 21.             
29. Iridium--Total,4 mg/L;                                                                                                                              
 Digestion 4 followed by:                                                                                                                               
    AA direct aspiration or...        235.1  3111 B                                                                                                     
    AA furnace................        235.2                                                                                                             
30. Iron--Total,4 mg/L;                                                                                                                                 
 Digestion 4 followed by:                                                                                                                               
    AA direct aspiration 36...        236.1  3111 B or C...............  D1068-90(A or B).............  I-3381-85................  974.27.3             
    AA furnace................        236.2  3113 B....................  D1068-90(C)                                                                    
    ICP/AES 36................      5 200.7  3120 B                                                                                                     
    DCP 36 or.................  ...........  ..........................  D4190-82(88).................  .........................  Note 34.             
    Colorimetric                ...........  3500-Fe D.................  D1068-90(D)..................  .........................  Note 22.             
     (Phenanthroline).                                                                                                                                  
31. Kjeldahl Nitrogen--Total,                                                                                                                           
 (as N), mg/L:                                                                                                                                          
    Digestion and distillation        351.3  4500-NH3 B or C...........  D3590-89(A)..................  .........................  .....................
     followed by:.                                                                                                                                      
    Titration.................        351.3  4500-NH3 E................  D3590-89(A)..................  .........................  973.483.             
    Nesslerization............        351.3  4500-NH3 C................  D3590-89(A)..................  .........................  .....................
    Electrode.................        351.3  4500-NH3 F or G...........  .............................  .........................  .....................
    Automated phenate                 351.1  ..........................  .............................  I-4551-788...............  .....................
     colorimetric.                                                                                                                                      
    Semi-automated block              351.2  ..........................  D3590-89(B)..................  .........................  .....................
     digester colorimetric.                                                                                                                             
    Manual or block digester          351.4  ..........................  D3590-89(A)..................  .........................  .....................
     potentiometric.                                                                                                                                    
    Block Digester, followed                                                                                                                            
     by:.                                                                                                                                               
    Auto distillation and       ...........  ..........................  .............................  .........................  Note 39.             
     Titration, or.                                                                                                                                     
    Nesslerization............  ...........  ..........................  .............................  .........................  Note 40.             
    Flow injection gas          ...........  ..........................  .............................  .........................  Note 41.             
     diffusion.                                                                                                                                         
                                                                                                                                                        
32. Lead--Total,4 mg/L;                                                                                                                                 
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration 36...        239.1  3111 B or C...............  D3559-90(A or B).............  I-3399-85................  974.27.3             
    AA furnace................        239.2  3113 B....................  D3559-90(D)                                                                    
    ICP/AES 36................      5 200.7  3120 B                                                                                                     
    DCP 36....................  ...........  ..........................  D4190-82(88).................  .........................  Note 34.             
    Voltametry 11 or..........  ...........  ..........................  D3559-90(C)                                                                    
    Colorimetric (Dithizone)..  ...........  3500-Pb D                                                                                                  
33. Magnesium--Total,\4\ mg/L;                                                                                                                          
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration......        242.1  3111 B....................  D511-93(B)...................  I-3447-85................  974.27.\3\           
    ICP/AES...................    \5\ 200.7  3120 B                                                                                                     
    DCP, or...................  ...........  ..........................  .............................  .........................  Note 34.             
    Gravimetric...............  ...........  3500-Mg D                                                                                                  
34. Manganese--Total,\4\ mg/L;                                                                                                                          
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration \36\.        243.1  3111 B....................  D858-90(A or B)..............  I-3454-85................  974.27.\3\           
    AA furnace................        243.2  3113 B....................  D858-90(C)                                                                     
    ICP/AES \36\..............    \5\ 200.7  3120 B                                                                                                     
    DCP \36\ or...............  ...........  ..........................  D4190-82(88).................  .........................  Note 34.             
    Colorimetric (Persulfate),  ...........  3500-Mn D.................  .............................  .........................  920.203.\3\          
     or.                                                                                                                                                
    (Periodate)...............  ...........  ..........................  .............................  .........................  Note 23.             
35. Mercury--Total,\4\ mg/L:                                                                                                                            
    Cold vapor, manual or.....        245.1  3112 B....................  D3223-91.....................  I-3462-85................  977.22.\3\           
    Automated.................        245.2                                                                                                             
36. Molybdenum--Total,\4\ mg/                                                                                                                           
 L; Digestion \4\ followed by:                                                                                                                          
    AA direct aspiration......        246.1  3111 D....................  .............................  I-3490-85                                       
    AA furnace................        246.2  3113 B                                                                                                     
    ICP/AES...................    \5\ 200.7  3120 B                                                                                                     

[[Page 12]]

                                                                                                                                                        
    DCP.......................  ...........  ..........................  .............................  .........................  Note 34.             
37. Nickel--Total,\4\ mg/L;                                                                                                                             
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration \36\.        249.1  3111 B or C...............  D1886-90(A or B).............  I-3499-85                                       
    AA furnace................        249.2  3113 B....................  D1886-90(C)                                                                    
    ICP/AES \36\..............    \5\ 200.7  3120 B                                                                                                     
    DCP \36\, or..............  ...........  ..........................  D4190-82(88).................  .........................  Note 34.             
    Colorimetric (heptoxime)..  ...........  3500-Ni D                                                                                                  
38. Nitrate (as N), mg/L:                                                                                                                               
    Colorimetric (Brucine             352.1  ..........................  .............................  .........................  973.50,\3\ 419 D,\17\
     sulfate), or Nitrate-                                                                                                          p. 28.\9\           
     nitrite N minus Nitrite N                                                                                                                          
     (See parameters 39 and                                                                                                                             
     40).                                                                                                                                               
39. Nitrate-nitrite (as N), mg/                                                                                                                         
 L:                                                                                                                                                     
    Cadmium reduction, Manual         353.3  4500-NO3- E...............  D3867-90(B)                                                                    
     or.                                                                                                                                                
    Automated, or.............        353.2  4500-NO3- F...............  D3867-90(A)..................  I-4545-85                                       
    Automated hydrazine.......        353.1  4500-NO3- H                                                                                                
40. Nitrite (as N), mg/L;                                                                                                                               
 Spectrophotometric:                                                                                                                                    
    Manual or.................        354.1  4500-NO2- B...............  .............................  .........................  Note 25.             
    Automated (Diazotization).  ...........  ..........................  .............................  I-4540-85                                       
41. Oil and grease--Total                                                                                                                               
 recoverable, mg/L:                                                                                                                                     
    Gravimetric (extraction)..        413.1  5520 B \38\                                                                                                
42. Organic carbon--Total                                                                                                                               
 (TOC), mg/L:                                                                                                                                           
    Combustion or oxidation...        415.1  5310 B, C, or D...........  D2579-93 (A or B)............  .........................  973.47,3 p. 14.24    
43. Organic nitrogen (as N),                                                                                                                            
 mg/L:                                                                                                                                                  
    Total Kjeldahl N                                                                                                                                    
     (Parameter 31) minus                                                                                                                               
     ammonia N (Parameter 4)                                                                                                                            
44. Orthophosphate (as P), mg/                                                                                                                          
 L; Ascorbic acid method:                                                                                                                               
    Automated, or.............        365.1  4500-P F..................  .............................  I-4601-85................  973.56.3             
    Manual single reagent.....        365.2  4500-P E..................  D515-88(A)                     .........................  973.55 \3\.          
    Manual two reagent........        365.3                                                                                                             
45. Osmium--Total \4\, mg/L;                                                                                                                            
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration, or..        252.1  3111 D                                                                                                     
    AA furnace................        252.2                                                                                                             
46. Oxygen, dissolved, mg/L:                                                                                                                            
    Winkler (Azide                    360.2  4500-O C..................  D888-92(A)...................  I-1575-78 \8\............  973.45B.3            
     modification), or.                                                                                                                                 
    Electrode.................        360.1  4500-O G..................  D888-92(B)...................  I-1576-78 \8\                                   
47. Palladium--Total,\4\ mg/L;                                                                                                                          
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration, or..        253.1  3111 B....................  .............................  .........................  p. S27.\10\          
    AA furnace................        253.2  ..........................  .............................  .........................  p. S28.\10\          
    DCP.......................  ...........  ..........................  .............................  .........................  Note 34.             
48. Phenols, mg/L:                                                                                                                                      
    Manual distillation \26\..        420.1  ..........................  .............................  .........................  Note 27.             
    Followed by:                                                                                                                                        
        Colorimetric (4AAP)           420.1  ..........................  .............................  .........................  Note 27.             
         manual, or                                                                                                                                     
        Automated \19\........        420.2                                                                                                             
49. Phosphorus (elemental), mg/                                                                                                                         
 L:                                                                                                                                                     

[[Page 13]]

                                                                                                                                                        
    Gas-liquid chromatography.  ...........  ..........................  .............................  .........................  Note 28.             
50. Phosphorus--Total, mg/L:                                                                                                                            
    Persulfate digestion              365.2  4500-P B,5................  .............................  .........................  973.55.\3\           
     followed by.                                                                                                                                       
    Manual or.................     365.2 or  4500-P E..................  D515-88(A)                                                                     
                                      365.3                                                                                                             
    Automated ascorbic acid           365.1  4500-P F..................  .............................  I-4600-85................  973.56.\3\           
     reduction.                                                                                                                                         
    Semi-automated block              365.4  ..........................  D515-88(B)                                                                     
     digestor.                                                                                                                                          
51. Platinum--Total,\4\ mg/L;                                                                                                                           
 Digestion \4\ followed by:                                                                                                                             
  AA direct aspiration........        255.1  3111 B                                                                                                     
    AA furnace................        255.2                                                                                                             
    DCP.......................  ...........  ..........................  .............................  .........................  Note 34.             
52. Potassium--Total,\4\ mg/L;                                                                                                                          
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration......        258.1  3111 B....................  .............................  I-3630-85................  973.53.\3\           
    ICP/AES...................    \5\ 200.7  3120 B                                                                                                     
    Flame photometric, or.....  ...........  3500-K D                                                                                                   
    Colorimetric..............  ...........  ..........................  .............................  .........................  317 B.\17\           
53. Residue--Total, mg/L:                                                                                                                               
    Gravimetric, 103-105 deg..        160.3  2540 B....................  .............................  I-3750-85                                       
54. Residue--filterable, mg/L:                                                                                                                          
    Gravimetric, 180 deg......        160.1  2540 C....................  .............................  I-1750-85                                       
55. Residue--nonfilterable                                                                                                                              
 (TSS), mg/L:                                                                                                                                           
    Gravimetric, 103-105 deg.         160.2  2540 D....................  .............................  I-3765-85                                       
     post washing of residue.                                                                                                                           
56. Residue--settleable, mg/L:                                                                                                                          
    Volumetric, (Imhoff cone),        160.5  2540 F                                                                                                     
     or gravimetric.                                                                                                                                    
57. Residue--Volatile, mg/L:                                                                                                                            
    Gravimetric, 550 deg......        160.4  ..........................  .............................  I-3753-85                                       
58. Rhodium--Total,\4\ mg/L;                                                                                                                            
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration, or..        265.1  3111 B                                                                                                     
    AA furnace................        265.2                                                                                                             
59. Ruthenium--Total,\4\ mg/L;                                                                                                                          
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration, or..        267.1  3111 B                                                                                                     
    AA furnace................        267.2                                                                                                             
60. Selenium--Total,\4\ mg/L;                                                                                                                           
 Digestion \4\ followed by:                                                                                                                             
    AA furnace................        270.2  3113 B....................  D3859-93(B)                                                                    
    ICP/AES,\36\ or...........    \5\ 200.7  3120 B                                                                                                     
    AA gaseous hydride........  ...........  3114 B....................  D3859-93(A)..................  I-3667-85                                       
61. Silica \37\--Dissolved, mg/                                                                                                                         
 L; 0.45 micron filtration                                                                                                                              
 followed by:                                                                                                                                           
    Colorimetric, Manual or...        370.1  4500-Si D.................  D859-88......................  I-1700-85                                       
    Automated                   ...........  ..........................  .............................  I-2700-85                                       
     (Molybdosilicate), or.                                                                                                                             
    ICP.......................    \5\ 200.7  3120 B                                                                                                     
62. Silver--Total,\4\ mg/L;                                                                                                                             
 Digestion 4, 29 followed by:                                                                                                                           
    AA direct aspiration......        272.1  3111 B or C...............  .............................  I-3720-85................  974.27,\3\ p. 37.\9\ 
    AA furnace................        272.2  3113 B                                                                                                     
    ICP/AES...................    \5\ 200.7  3120 B                                                                                                     
    DCP.......................  ...........  ..........................  .............................  .........................  Note 34.             
63. Sodium--Total,\4\ mg/L;                                                                                                                             
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration......        273.1  3111 B....................  .............................  I-3735-85................  973.54.\3\           
    ICP/AES...................    \5\ 200.7  3120 B                                                                                                     
     DCP, or..................  ...........  ..........................  .............................  .........................  Note 34.             

[[Page 14]]

                                                                                                                                                        
    Flame photometric.........  ...........  3500 Na D                                                                                                  
64. Specific conductance,                                                                                                                               
 micromhos/cm at 25  deg.C:                                                                                                                             
    Wheatstone bridge.........        120.1  2510 B....................  D1125-91(A)..................  I-1780-85................  973.40.\3\           
65. Sulfate (as SO4), mg/L:                                                                                                                             
    Automated colorimetric            375.1                                                                                                             
     (barium chloranilate).                                                                                                                             
    Gravimetric...............        375.3  4500-SO4-2 C or D.........  .............................  .........................  925.54.\3\           
    Turbidimetric, or.........        375.4  ..........................  D516-90......................  .........................  426C.\30\            
66. Sulfide (as S), mg/L:                                                                                                                               
    Titrimetric (iodine), or..        376.1  4500-S-2 E................  .............................  I-3840-85                                       
    Colorimetric (methylene           376.2  4500-S-2 D                                                                                                 
     blue).                                                                                                                                             
67. Sulfite (as SO3), mg/L:                                                                                                                             
    Titrimetric (iodine-              377.1  4500-SO3-2 B                                                                                               
     iodate).                                                                                                                                           
68. Surfactants, mg/L:                                                                                                                                  
    Colorimetric (methylene           425.1  5540 C....................  D2330-88                                                                       
     blue).                                                                                                                                             
69. Temperature,  deg.C:                                                                                                                                
    Thermometric..............        170.1  2550 B....................  .............................  .........................  Note 32.             
70. Thallium--Total,\4\ mg/L;                                                                                                                           
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration......        279.1  3111 B                                                                                                     
    AA furnace................        279.2                                                                                                             
    ICP/AES, or...............    \5\ 200.7  3120 B                                                                                                     
71. Tin--Total,\4\ mg/L;                                                                                                                                
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration......        282.1  3111 B....................  .............................  I-3850-78 \8\                                   
    AA furnace, or............        282.2  3113 B                                                                                                     
    ICP/AES...................    \5\ 200.7                                                                                                             
72. Titanium--Total,\4\ mg/L;                                                                                                                           
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration......        283.1  3111 D                                                                                                     
    AA furnace................        283.2                                                                                                             
    DCP.......................  ...........  ..........................  .............................  .........................  Note 34.             
73. Turbidity, NTU:                                                                                                                                     
    Nephelometric.............        180.1  2130 B....................  D1889-88(A)..................  I-3860-85                                       
74. Vanadium--Total,\4\ mg/L;                                                                                                                           
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration......        286.1  3111 D                                                                                                     
    AA furnace................        286.2  ..........................  D3373-93                                                                       
    ICP/AES...................    \5\ 200.7  3120 B                                                                                                     
    DCP, or...................  ...........  ..........................  D4190-82(88).................  .........................  Note 34.             
    Colorimetric (Gallic acid)  ...........  3500-V D                                                                                                   
75. Zinc--Total,\4\ mg/L;                                                                                                                               
 Digestion \4\ followed by:                                                                                                                             
    AA direct aspiration \36\.        289.1  3111 B or C...............  D1691-90 (A or B)............  I-3900-85................  974.27,\3\ p. 37.\9\ 
    AA furnace................        289.2                                                                                                             
    ICP/AES \36\..............    \5\ 200.7  3120 B                                                                                                     
    DCP,\36\ or...............  ...........  ..........................  D4190-82(88).................  .........................  Note 34.             
    Colorimetric (Dithizone)    ...........  3500-Zn E                                                                                                  
     or.                                                                                                                                                

[[Page 15]]

                                                                                                                                                        
    (Zincon)..................  ...........  3500-Zn F.................  .............................  .........................  Note 33.             
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table IB Notes:                                                                                                                                         
\1\ ``Methods for Chemical Analysis of Water and Wastes'', Environmental Protection Agency, Environmental Monitoring Systems Laboratory-Cincinnati (EMSL-
  CI), EPA-600/4-79-020, Revised March 1983 and 1979 where applicable.                                                                                  
\2\ Fishman, M.J., et al, ``Methods for Analysis of Inorganic Substances in Water and Fluvial Sediments,'' U.S. Department of the Interior, Techniques  
  of Water--Resource Investigations of the U.S. Geological Survey, Denver, CO, Revised 1989, unless otherwise stated.                                   
\3\ ``Official Methods of Analysis of the Association of Official Analytical Chemists,'' methods manual, 15th ed. (1990).                               
\4\ For the determination of total metals the sample is not filtered before processing. A digestion procedure is required to solubilize suspended       
  material and to destroy possible organic-metal complexes. Two digestion procedures are given in ``Methods for Chemical Analysis of Water and Wastes,  
  1979 and 1983''. One (section 4.1.3), is a vigorous digestion using nitric acid. A less vigorous digestion using nitric and hydrochloric acids        
  (section 4.1.4) is preferred; however, the analyst should be cautioned that this mild digestion may not suffice for all samples types. Particularly,  
  if a colorimetric procedure is to be employed, it is necessary to ensure that all organo-metallic bonds be broken so that the metal is in a reactive  
  state. In those situations, the vigorous digestion is to be preferred making certain that at no time does the sample go to dryness. Samples containing
  large amounts of organic materials may also benefit by this vigorous digestion, however, vigorous digestion with concentrated nitric acid will convert
  antimony and tin to insoluble oxides and render them unavailable for analysis. Use of ICP/AES as well as determinations for certain elements such as  
  antimony, arsenic, the noble metals, mercury, selenium, silver, tin, and titanium require a modified sample digestion procedure and in all cases the  
  method write-up should be consulted for specific instructions and/or cautions.                                                                        
Note to Table IB Note 4: If the digestion procedure for direct aspiration AA included in one of the other approved references is different than the     
  above, the EPA procedure must be used.                                                                                                                
Dissolved metals are defined as those constituents which will pass through a 0.45 micron membrane filter. Following filtration of the sample, the       
  referenced procedure for total metals must be followed. Sample digestion of the filtrate for dissolved metals (or digestion of the original sample    
  solution for total metals) may be omitted for AA (direct aspiration or graphite furnace) and ICP analyses, provided the sample solution to be analyzed
  meets the following criteria:                                                                                                                         
  a. has a low COD (<20)                                                                                                                                
  b. is visibly transparent with a turbidity measurement of 1 NTU or less                                                                               
  c. is colorless with no perceptible odor, and                                                                                                         
  d. is of one liquid phase and free of particulate or suspended matter following acidification.                                                        
\5\ The full text of Method 200.7, ``Inductively Coupled Plasma Atomic Emission Spectrometric Method for Trace Element Analysis of Water and Wastes,''  
  is given at Appendix C of this Part 136.                                                                                                              
\6\ Manual distillation is not required if comparability data on representative effluent samples are on company file to show that this preliminary      
  distillation step is not necessary: however, manual distillation will be required to resolve any controversies.                                       
\7\ Ammonia, Automated Electrode Method, Industrial Method Number 379-75 WE, dated February 19, 1976, (Bran & Luebbe (Technicon) Auto Analyzer II, Bran 
  & Luebbe Analyzing Technologies, Inc., Elmsford, NY 10523.                                                                                            
\8\ The approved method is that cited in ``Methods for Determination of Inorganic Substances in Water and Fluvial Sediments'', USGS TWRI, Book 5,       
  Chapter A1 (1979).                                                                                                                                    
\9\ American National Standard on Photographic Processing Effluents, Apr. 2, 1975. Available from ANSI, 1430 Broadway, New York, NY 10018.              
\10\ ``Selected Analytical Methods Approved and Cited by the United States Environmental Protection Agency'', Supplement to the Fifteenth Edition of    
  Standard Methods for the Examination of Water and Wastewater (1981).                                                                                  
\11\ The use of normal and differential pulse voltage ramps to increase sensitivity and resolution is acceptable.                                       
\12\ Carbonaceous biochemical oxygen demand (CBOD5) must not be confused with the traditional BOD5 test which measures ``total BOD''. The addition of   
  the nitrification inhibitor is not a procedural option, but must be included to report the CBOD5 parameter. A discharger whose permit requires        
  reporting the traditional BOD5 may not use a nitrification inhibitor in the procedure for reporting the results. Only when a discharger's permit      
  specifically states CBOD5 is required can the permittee report data using the nitrification inhibitor.                                                
\13\ OIC Chemical Oxygen Demand Method, Oceanography International Corporation, 1978, 512 West Loop, P.O. Box 2980, College Station, TX 77840.          
\14\ Chemical Oxygen Demand, Method 8000, Hach Handbook of Water Analysis, 1979, Hach Chemical Company, P.O. Box 389, Loveland, CO 80537.               
\15\ The back titration method will be used to resolve controversy.                                                                                     
\16\ Orion Research Instruction Manual, Residual Chlorine Electrode Model 97-70, 1977, Orion Research Incorporated, 840 Memorial Drive, Cambridge, MA   
  02138. The calibration graph for the Orion residual chlorine method must be derived using a reagent blank and three standard solutions, containing    
  0.2, 1.0, and 5.0 ml 0.00281 N potassium iodate/100 ml solution, respectively.                                                                        
\17\ The approved method is that cited in Standard Methods for the Examination of Water and Wastewater, 14th Edition, 1976.                             
\18\ National Council of the Paper Industry for Air and Stream Improvement, (Inc.) Technical Bulletin 253, December 1971.                               
\19\ Copper, Biocinchoinate Method, Method 8506, Hach Handbook of Water Analysis, 1979, Hach Chemical Company, P.O. Box 389, Loveland, CO 80537.        
\20\ After the manual distillation is completed, the autoanalyzer manifolds in EPA Methods 335.3 (cyanide) or 420.2 (phenols) are simplified by         
  connecting the re-sample line directly to the sampler. When using the mainfold setup shown in Method 335.3, the buffer 6.2 should be replaced with the
  buffer 7.6 found in Method 335.2.                                                                                                                     
\21\ Hydrogen ion (pH) Automated Electrode Method, Industrial Method Number 378-75WA, October 1976, Bran & Luebbe (Technicon) Autoanalyzer II. Bran &   
  Luebbe Analyzing Technologies, Inc., Elmsford, NY 10523.                                                                                              
\22\ Iron, 1,10-Phenanthroline Method, Method 8008, 1980, Hach Chemical Company, P.O. Box 389, Loveland, CO 80537.                                      
\23\ Manganese, Periodate Oxidation Method, Method 8034, Hach Handbook of Wastewater Analysis, 1979, pages 2-113 and 2-117, Hach Chemical Company,      
  Loveland, CO 80537.                                                                                                                                   
\24\ Wershaw, R.L., et al, ``Methods for Analysis of Organic Substances in Water,'' Techniques of Water-Resources Investigation of the U.S. Geological  
  Survey, Book 5, Chapter A3, (1972 Revised 1987) p. 14.                                                                                                
\25\ Nitrogen, Nitrite, Method 8507, Hach Chemical Company, P.O. Box 389, Loveland, CO 80537.                                                           
\26\ Just prior to distillation, adjust the sulfuric-acid-preserved sample to pH 4 with 1 + 9 NaOH.                                                     

[[Page 16]]

                                                                                                                                                        
\27\ The approved method is cited in Standard Methods for the Examination of Water and Wastewater, 14th Edition. The colorimetric reaction is conducted 
  at a pH of 10.00.2. The approved methods are given on pp 576-81 of the 14th Edition: Method 510A for distillation, Method 510B for the    
  manual colorimetric procedure, or Method 510C for the manual spectophotometric procedure.                                                             
\28\ R. F. Addison and R.G. Ackman, ``Direct Determination of Elemental Phosphorus by Gas-Liquid Chromatography,'' Journal of Chromatography, vol. 47,  
  No. 3, pp. 421-426, 1970.                                                                                                                             
\29\ Approved methods for the analysis of silver in industrial wastewaters at concentrations of 1 mg/L and above are inadequate where silver exists as  
  an inorganic halide. Silver halides such as the bromide and chloride are relatively insoluble in reagents such as nitric acid but are readily soluble 
  in an aqueous buffer of sodium thiosulfate and sodium hydroxide to pH of 12. Therefore, for levels of silver above 1 mg/L, 20 mL of sample should be  
  diluted to 100 mL by adding 40 mL each of 2 M Na2S2O3 and NaOH. Standards should be prepared in the same manner. For levels of silver below 1 mg/L the
  approved method is satisfactory.                                                                                                                      
\30\ The approved method is that cited in Standard Methods for the Examination of Water and Wastewater, 15th Edition.                                   
\31\ EPA Methods 335.2 and 335.3 require the NaOH absorber solution final concentration to be adjusted to 0.25 N before colorimetric determination of   
  total cyanide.                                                                                                                                        
\32\ Stevens, H.H., Ficke, J.F., and Smoot, G.F., ``Water Temperature--Influential Factors, Field Measurement and Data Presentation'', Techniques of    
  Water-Resources Investigations of the U.S. Geological Survey, Book 1, Chapter D1, 1975.                                                               
\33\ Zinc, Zincon Method, Method 8009, Hach Handbook of Water Analysis, 1979, pages 2-231 and 2-333, Hach Chemical Company, Loveland, CO 80537.         
\34\ ``Direct Current Plasma (DCP) Optical Emission Spectrometric Method for Trace Elemental Analysis of Water and Wastes, Method AES0029,'' 1986--     
  Revised 1991, Fison Instruments, Inc., 32 Commerce Center, Cherry Hill Drive, Danvers, MA 01923.                                                      
\35\ Precision and recovery statements for the atomic absorption direct aspiration and graphite furnace methods, and for the spectrophotometric SDDC    
  method for arsenic are provided in Appendix D of this part titled, ``Precision and Recovery Statements for Methods for Measuring Metals''.            
\36\ ``Closed Vessel Microwave Digestion of Wastewater Samples for Determination of Metals'', CEM Corporation, P.O. Box 200, Matthews, NC 28106-0200,   
  April 16, 1992. Available from the CEM Corporation.                                                                                                   
\37\ When determining boron and silica, only plastic, PTFE, or quartz laboratory ware may be used from start until completion of analysis.              
\38\ Only the trichlorofluoromethane extraction solvent is approved.                                                                                    
\39\ Nitrogen, Total Kjeldahl, Method PAI-DK01 (Block Digestion, Steam Distillation, Titrimetric Detection), revised 12/22/94, Perstop Analytical       
  Corporation.                                                                                                                                          
\40\ Nitrogen, Total Kjeldahl, Method PAI-DK02 (Block Digestion, Steam Distillation, Colorimetric Detection), revised 12/22/94, Perstop Analytical      
  Corporation.                                                                                                                                          
\41\ Nitrogen, Total Kjeldahl, Method PAI-DK03 (Block Digestion, Automated FIA Gas Diffusion), revised 12/22/94, Perstop Analytical Corporation.        


                                     Table IC.--List of Approved Test Procedures for Non-Pesticide Organic Compounds                                    
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 EPA method number 2 7                                                  
        Parameter \1\         --------------------------------------------------------------------------------------------------------------------------
                                       GC                 GC/MS           HPLC         Standard method 18th Ed.              ASTM              Other    
--------------------------------------------------------------------------------------------------------------------------------------------------------
 1. Acenaphthene.............                 610           625, 1625        610  6410 B, 6440 B                     D4657-92                           
 2. Acenaphthylene...........                 610           625, 1625        610  6410 B, 6440 B                     D4657-92                           
 3. Acrolein.................                 603       \4\ 604, 1624  .........  .................................  ....................               
 4. Acrylonitrile............                 603       \4\ 624, 1624        610  .................................  ....................               
 5. Anthracene...............                 610           625, 1625        610  6410 B, 6440 B                     D4657-92                           
 6. Benzene..................                 602           624, 1624  .........  6210 B, 6220 B                     ....................               
 7. Benzidine................  ..................       \5\ 625, 1625        605  .................................  ....................  Note 3, p.1. 
 8. Benzo(a)anthracene.......                 610           625, 1625        610  6410 B, 6440 B                     D4657-92                           
 9. Benzo(a)pyrene...........                 610           625, 1625        610  6410 B, 6440 B                     D4657-92                           
 10. Benzo(b)fluoranthene....                 610           625, 1625        610  6410 B, 6440 B                     D4657-92                           
 11. Benzo(g, h, i)perylene..                 610           625, 1625        610  6410 B, 6440 B                     D4657-92                           
 12. Benzo(k)fluoranthene....                 610           625, 1625        610  6410 B, 6440 B                     D4657-92                           
 13. Benzyl chloride.........  ..................  ..................  .........  .................................  ....................  Note 3,      
                                                                                                                                            p.130: Note 
                                                                                                                                            6, p. S102. 
 14. Benzyl butyl phthalate..                 606           625, 1625  .........  6410 B                             ....................  .............
 15. Bis(2-chloroethoxy)                      611           625, 1625  .........  6410 B                             ....................               
 methane.                                                                                                                                               
 16. Bis(2-chloroethyl) ether                 611           625, 1625  .........  6410 B                             ....................               
 17. Bis (2-ethylhexyl)                       606           625, 1625  .........  6410 B, 6230 B                     ....................               
 phthalate.                                                                                                                                             
 18. Bromodichloromethane....                 601           624, 1624  .........  6210 B, 6230 B                     ....................               
 19. Bromoform...............                 601           624, 1624  .........  6210 B, 6230 B                     ....................               
 20. Bromomethane............                 601           624, 1624  .........  6210 B, 6230 B                     ....................               
 21. 4-Bromophenylphenyl                      611           625, 1625  .........  6410 B                             ....................               
 ether.                                                                                                                                                 

[[Page 17]]

                                                                                                                                                        
 22. Carbon tetrachloride....                 601           624, 1624  .........  6230 B, 6410 B                     ....................  Note 3,      
                                                                                                                                            p.130.      
 23. 4-Chloro-3-methylphenol.                 604           625, 1625  .........  6410 B, 6420 B                     ....................               
 24. Chlorobenzene...........            601, 602           624, 1624  .........  6210 B, 6220 B                     ....................  Note 3,      
                                                                                  6230 B                                                    p.130.      
 25. Chloroethane............                 601           624, 1624  .........  6210 B, 6230 B                     ....................               
 26. 2-Chloroethylvinyl ether                 601           624, 1624  .........  6210 B, 6230 B                     ....................  .............
 27. Chloraform..............                 601           624, 1624  .........  6210 B, 6230 B                     ....................  Note, p.130. 
 28. Chloromethane...........                 601           624, 1624  .........  6210 B. 6230 B                     ....................               
 29. 2-Chloronaphthalene.....                 612           625, 1625  .........  6410 B                             ....................               
 30. 2-Chlorophenol..........                 604           625, 1625  .........  6410 B, 6420 B                     ....................               
 31. 4-Chlorophenylphenyl                     611           625, 1625  .........  6410 B                             ....................               
 ether.                                                                                                                                                 
 32. Chrysene................                 610           625, 1625        610  6410 B, 6440 B                     D4657-92                           
 33. Dibenzo(a,h)anthracene..                 610           625, 1625        610  6410 B, 6440 B                     D4657-92                           
 34. Dibromochloromethane....                 601           624, 1624  .........  6210 B, 6230 B                     ....................               
 35. 1, 2-Dichlorobenzene....         601,602,612        624,625,1625  .........  6410 B, 6230 B, 6220 B             ....................               
 36. 1, 3-Dichlorobenzene....         601,602,612        624,625,1625  .........  6410 B, 6230 B, 6220 B             ....................               
 37. 1,4-Dichlorobenzene.....       601, 602, 612      624, 625, 1625  .........  6410 B, 6220 B, 6230 B                                                
 38. 3, 3-Dichlorobenzidine..  ..................           625, 1625        605  6410 B                             ....................               
 39. Dichlorodifluoromethane.                 601  ..................  .........  6230 B                             ....................               
 40. 1, 1-Dichloroethane.....                 601           624, 1624  .........  6230 B, 6210 B                     ....................               
 41. 1, 2-Dichloroethane.....                 601           624, 1624  .........  6230 B, 6210 B                     ....................               
 42. 1, 1-Dichloroethene.....                 601           624, 1624  .........  6230 B, 6210 B                     ....................               
 43. trans-1, 2-                              601           624, 1624  .........  6230 B, 6210 B                     ....................               
 Dichloroethene.                                                                                                                                        
 44. 2, 4-Dichlorophenol.....                 604           625, 1625  .........  6420 B, 6410 B                     ....................               
 45. 1, 2-Dichloropropane....                 601           624, 1624  .........  6230 B, 6210 B                     ....................               
 46. cis-1, 3-Dichloropropene                 601           624, 1624  .........  6230 B, 6210 B                     ....................               
 47. trans-1, 3-                              601           624, 1624  .........  6230 B, 6210 B                     ....................               
 Dichloropropene.                                                                                                                                       
 48. Diethyl phthalate.......                 606           625, 1625  .........  6410 B                             ....................               
 49. 2, 4-Dimethylphenol.....                 604           625, 1625  .........  6420 B, 6410 B                     ....................               
 50. Dimethyl phthalate......                 606           625, 1625  .........  6410 B                             ....................               
 51. Di-n-butyl phthalate....                 606           625, 1625  .........  6410 B                             ....................               
 52. Di-n-octyl phthalate....                 606           625, 1625  .........  6410 B                             ....................               
 53. 2, 3-Dinitrophenol......                 604           625, 1625  .........  6420 B, 6410 B                     ....................               
 54. 2,4-Dinitrotoluene......                 609           625, 1625  .........  6410 B                                                                
 55. 2, 6-Dinitrotoluene.....                 609           625, 1625  .........  6410 B                             ....................               
 56. Epichlorohydrin.........  ..................  ..................  .........  .................................  ....................  Note 3, p.130
                                                                                                                                            Note 6,     
                                                                                                                                            p.S102.     
 57. Ethylbenzene............                 602           624, 1624  .........  6220 B, 6210 B                     ....................               
 58. Fluoranthene............                 610           625, 1625        610  6410 B, 6440 B                     D4657-92                           
 59. Fluorene................                 610           625, 1625        610  6410 B, 6440 B                     D4657-92                           
 60. Hexachlorobenzene.......                 612           625, 1625  .........  6410 B                             ....................               
 61. Hexachlorobutadiene.....                 612           625, 1625  .........  6410 B                             ....................               
 62.                                          612       \5\ 625, 1625  .........  6410 B                             ....................               
 Hexachlorocyclopentadiene.                                                                                                                             
 63. Hexachloroethane........                 616           625, 1625  .........  6410 B                             ....................               
 64. Ideno(1,2,3-cd) pyrene..                 610           625, 1625        610  6410 B, 6440 B                     D4657-92                           
 65. Isophorone..............                 609           625, 1625  .........  6410 B                             ....................               
 66. Methylene chloride......                 601           624, 1624  .........  6230 B                             ....................  Note 3,      
                                                                                                                                            p.130.      
 67. 2-Methyl-4,6-                            604           625, 1625  .........  6420 B, 6410 B                                                        
 dinitrophenol.                                                                                                                                         
 68. Naphthalene.............                 610           625, 1625        610  6410 B, 6440 B                     ....................               

[[Page 18]]

                                                                                                                                                        
 69. Nitrobenezene...........                 609           625, 1625  .........  6410 B                                                                
 70. 2-Nitrophenol...........                 604           625, 1625  .........  6410 B, 6420 B                     ....................               
 71. 4-Nitrophenol...........                 604           625, 1625  .........  6410 B, 6420 B                     ....................               
 72. N-Nitrosodimethylamine..                 607           625, 1625  .........  6410 B                             ....................               
 73. N-Nitrosodi-n-                           607        \5\625, 1625  .........  6410 B                             ....................               
 propylamine.                                                                                                                                           
 74. N-Nitrosodiphenylamine..                 607        \5\625, 1625  .........  6410 B                             ....................               
 75. 2,2-Oxybis(1-                            611           625, 1625  .........  6410 B                             ....................               
 chloropropane).                                                                                                                                        
 76. PCB-1016................                 608                 625  .........  6410 B                             ....................  Note 3, p.   
                                                                                                                                            43; note 8. 
 77. PCB-1221................                 608                 625  .........  6410 B                             ....................  Note 3, p.   
                                                                                                                                            43; note 8. 
 78. PCB-1232................                 608                 625  .........  6410 B                             ....................  Note 3, p.   
                                                                                                                                            43; note 8. 
 79. PCB-1242................                 608                 625  .........  6410 B                             ....................  Note 3, p.   
                                                                                                                                            43; note 8. 
 80. PCB-1248................                 608                 625  .........  .................................  ....................  Note 3, p.   
                                                                                                                                            43; note 8. 
 81. PCB-1254................                 608                 625  .........  6410 B                             ....................  Note 3, p.   
                                                                                                                                            43; note 8. 
 82. PCB-1260................                 608                 625  .........  6410 B, 6630 B                     ....................  Note 3, p.   
                                                                                                                                            43; note 8. 
 83. Pentachlorophenol.......                 604           625, 1625  .........  6410 B, 6630 B                     ....................  Note 3,      
                                                                                                                                            p.140.      
 84. Phenanthrene............                 610           625, 1625        610  6410 B, 6440 B                     D4657-92                           
 85. Phenol..................                 604           625, 1625  .........  6420 B, 6410 B                     ....................               
 86. Pyrene..................                 610           625, 1625        610  6410 B, 6440 B                     D4675-92                           
 87. 2,3,7,8-                  ..................              5a 613  .........  .................................  ....................               
 Tetrachlorodibenzo-p-dioxin.                                                                                                                           
 88. 1,1,2,2-                                 601           624, 1624  .........  6230 B, 6210 B                     ....................  Note 3,      
 Tetrachloroethane.                                                                                                                         p.130.      
 89. Tetrachloroethene.......                 601           624, 1624  .........  6230 B, 6210 B                     ....................  Note 3,      
                                                                                                                                            p.130.      
 90. Toluene.................                 602           624, 1624  .........  6210 B, 6220 B                     ....................               
 91. 1,2,4-Trichlorobenzene..                 612           625, 1625  .........  6410 B                             ....................  Note 3,      
                                                                                                                                            p.130.      
 92. 1,1,1-Trichloroethane...                 601           624, 1624  .........  6210 B, 6230 B                     ....................               
 93. 1,1,2-Trichloroethane...                 601           624, 1624  .........  6210 B, 6230 B                     ....................  Note 3,      
                                                                                                                                            p.130.      
 94. Trichloroethene.........                 601           624, 1624  .........  6210 B, 6230 B                     ....................               
 95. Trichlorofluoromethane..                 601                 624  .........  6210 B, 6230 B                     ....................               
 96. 2,4,6-Trichlorophenol...                 604           625, 1625  .........  6410 B, 6240 B                     ....................               
 97. Vinyl chloride..........                 601           624, 1624  .........  6210 B, 6230 B                     ....................               
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 1C notes:                                                                                                                                         
\1\ All parameters are expressed in micrograms per liter (g/L).                                                                                
\2\ The full text of Methods 601-613, 624, 625, 1624, and 1625, are given at appendix A, ``Test Procedures for Analysis of Organic Pollutants,'' of this
  part 136. The standardized test procedure to be used to determine the method detection limit (MDL) for these test procedures is given at appendix B,  
  ``Definition and Procedure for the Determination of the Method Detection Limit'' of this part 136.                                                    
\3\ ``Methods for Benzidine: Chlorinated Organic Compounds, Pentachlorophenol and Pesticides in Water and Wastewater,'' U.S. Environmental Protection   
  Agency, September, 1978.                                                                                                                              
\4\ Method 624 may be extended to screen samples for Acrolein and Acrylonitrile. However, when they are known to be present, the preferred method for   
  these two compounds is Method 603 or Method 1624.                                                                                                     

[[Page 19]]

                                                                                                                                                        
\5\ Method 625 may be extended to include benzidine, hexachlorocyclopentadiene, N-nitrosodimethylamine, and N-nitrosodiphenylamine. However, when they  
  are known to be present, Methods 605, 607, and 612, or Method 1625, are preferred methods for these compounds.                                        
5a 625, Screening only.                                                                                                                                 
\6\ ``Selected Analytical Methods Approved and Cited by the United States Environmental Protection Agency'', Supplement to the Fifteenth Edition of     
  Standard Methods for the Examination of Water and Wastewater (1981).                                                                                  
\7\ Each Analyst must make an initial, one-time demonstration of their ability to generate acceptable precision and accuracy with Methods 601-603, 624, 
  625, 1624, and 1625 (See Appendix A of this Part 136) in accordance with procedures each in section 8.2 of each of these Methods. Additionally, each  
  laboratory, on an on-going basis must spike and analyze 10% (5% for Methods 624 and 625 and 100% for methods 1624 and 1625) of all samples to monitor 
  and evaluate laboratory data quality in accordance with sections 8.3 and 8.4 of these Methods. When the recovery of any parameter falls outside the   
  warning limits, the analytical results for that parameter in the unspiked sample are suspect and cannot be reported to demonstrate regulatory         
  compliance.                                                                                                                                           
Note: These warning limits are promulgated as an ``interim final action with a request for comments.''                                                  
\8\ ``Organochlorine Pesticides and PCBs in Wastewater Using Empore TM Disk'', 3M Corporation Revised 10/28/94.                                         


                                             Table ID.--List of Approved Test Procedures for Pesticides \1\                                             
--------------------------------------------------------------------------------------------------------------------------------------------------------
            Parameter                        Method           EPA \2\ \7\  Standard methods 18th Ed.            ASTM                      Other         
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. Aldrin........................  GC                                 608  6630 B & C...............  D3086-90................  Note 3, p. 7; note 4, p.
                                                                                                                                 30; note 8.            
                                   GC/MS                              625  6410 B...................  ........................  ........................
2. Ametryn.......................  GC                         ...........  .........................  ........................  Note 3, p. 83; Note 6,  
                                                                                                                                 p. S68.                
3. Aminocarb.....................  TLC                        ...........  .........................  ........................  Note 3, p. 94; Note 6,  
                                                                                                                                 p. S16.                
4. Atraton.......................  GC                         ...........  .........................  ........................  Note 3, p. 83; Note 6,  
                                                                                                                                 p. S68.                
5. Atrazine......................  GC                         ...........  .........................  ........................  Note 3, p. 83; Note 6,  
                                                                                                                                 p. S68.                
6. Azinphos methyl...............  GC                         ...........  .........................  ........................  Note 3, p. 25; Note 6,  
                                                                                                                                 p. S51.                
7. Barban........................  TLC                        ...........  .........................  ........................  Note 3, p. 104; Note 6, 
                                                                                                                                 p. S64.                
8. -BHC.................  GC                                 608  6630 B & C...............  D3086-90................  Note 3, p. 7; note 8.   
                                   GC/MS                          \5\ 625  6410 B...................  ........................  ........................
9. -BHC.................  GC                                 608  6630 C...................  D3086-90................  Note 8.                 
                                   GC/MS                          \5\ 625  6410 B...................  ........................  ........................
10. -BHC................  GC                                 608  6630 C...................  D3086-90................  Note 8.                 
                                   GC/MS                          \5\ 625  6410 B...................  ........................  ........................
11. -BHC (Lindane)......  GC                                 608  6630 B & C...............  D3086-90................  Note 3, p. 7; note 4, p.
                                                                                                                                 30; note 8.            
                                   GC/MS                              625  6410 B...................  ........................  ........................
                                                                                                                                                        
12. Captan.......................  GC                         ...........  6630 B                     D3086-90                  Note 3, p. 7.           
13. Carbaryl.....................  TLC                        ...........  .........................  ........................  Note 3, p. 94: Note 6,  
                                                                                                                                 p. S60.                
14. Carbophenothion..............  GC                         ...........  .........................  ........................  Note 4, p. 30; Note 6,  
                                                                                                                                 p. S73.                
15. Chlordane....................  GC                                 608  6630 B & C...............  D3086-90................  Note 3, p. 7; note 8.   
                                   GC/MS                              625  6410 B...................  ........................  ........................
                                                                                                                                                        
16. Chloropropham................  TLC                        ...........  .........................  ........................  Note 3, p. 104; Note 6, 
                                                                                                                                 p. S64.                
17. 2,4-D........................  GC                         ...........  6640 B...................  ........................  Note 3, p. 115; Note 4, 
                                                                                                                                 p. 35.                 
18. 4,4'-DDD.....................  GC                                 608  6630 B & C...............  D3086-90................  Note 3, p. 7; note 4, p.
                                                                                                                                 30; note 8.            
                                   GC/MS                              625  6410 B...................  ........................  ........................
19. 4,4'-DDE.....................  GC                                 608  6630 B & C...............  D3086-90................  Note 3, p. 7; note 4, p.
                                                                                                                                 30; note 8.            
                                   GC/MS                              625  6410 B...................  ........................  ........................
20. 4,4'-DDT.....................  GC                                 608  6630 B & C...............  D3086-90................  Note 3, p. 7; note 4, p.
                                                                                                                                 30; note 8.            
                                   GC/MS                              625  6410 B...................  ........................  ........................
                                                                                                                                                        
21. Demeton-O....................  GC                         ...........  .........................  ........................  Note 3, p. 25; Note 6,  
                                                                                                                                 p. S51.                
22. Demeton-S....................  GC                         ...........  .........................  ........................  Note 3, p. 25: Note 6,  
                                                                                                                                 p. S51.                

[[Page 20]]

                                                                                                                                                        
23. Diazinon.....................  GC                         ...........  .........................  ........................  Note 3, p. 25; Note 4,  
                                                                                                                                 p. 30; Note 6, p. S51. 
24. Dicamba......................  GC                         ...........  .........................  ........................  Note 3, p. 115.         
25. Dichlofenthion...............  GC                         ...........  .........................  ........................  Note 4, p. 30; Note 6,  
                                                                                                                                 p. S73.                
26. Dichloran....................  GC                         ...........  6630 B & C...............  ........................  Note 3, p. 7.           
27. Dicofol......................  GC                         ...........  .........................  D3086-90................  ........................
28. Dieldrin.....................  GC                                 608  6630 B & C...............  ........................  Note 3, p. 7; note 4, p.
                                                                                                                                 30; note 8.            
                                   GC/MS                              625  6410 B...................  ........................  ........................
                                                                                                                                                        
29. Dioxathion...................  GC                         ...........  .........................  ........................  Note 4, p. 30; Note 6,  
                                                                                                                                 p. S73.                
30. Disulfoton...................  GC                         ...........  .........................  ........................  Note 3, p. 25; Note 6,  
                                                                                                                                 p. S51.                
31. Diuron.......................  TLC                        ...........  .........................  ........................  Note 3, p. 104; Note 6, 
                                                                                                                                 p. S64.                
32. Endosulfan I.................  GC                                 608  6630 B & C...............  D3086-90................  Note 3, p. 7; note 8.   
                                   GC/MS                          \5\ 625  6410 B...................  ........................  ........................
33. Endosulfan II................  GC                                 608  6630 B & C...............   D3086-90...............  Note 3, p. 7; note 8.   
                                   GC/MS                          \5\ 625  6410 B...................  ........................  ........................
34. Endosulfan Sulfate...........  GC                                 608  6630 C...................  ........................  Note 8.                 
                                   GC/MS                              625  6410 B...................  ........................  ........................
35. Endrin.......................  GC                                 608  6630 B & C...............  D3086-90................  Note 3, p. 7; note 4, p.
                                                                                                                                 30; note 8.            
                                   GC/MS                          \5\ 625  6410 B...................  ........................  ........................
36. Endrin aldehyde..............  GC                                 608  .........................  ........................  Note 8.                 
                                   GC/MS                              625  .........................  ........................  ........................
                                                                                                                                                        
37. Ethion.......................  GC                         ...........  .........................  ........................  Note 4, p. 30; Note 6,  
                                                                                                                                 p. S73.                
38. Fenuron......................  TLC                        ...........  .........................  ........................  Note 3, p. 104; Note 6, 
                                                                                                                                 p. S64.                
39. Fenuron-TCA..................  TLC                        ...........  .........................  ........................  Note 3, p. 104; Note 6, 
                                                                                                                                 p. S64.                
40. Heptachlor...................  GC                                 608  6630 B & C...............  D3086-90................  Note 3, p. 7; note 4, p.
                                                                                                                                 30; note 8.            
                                   GC/MS                              625  6410 B...................  ........................  ........................
41. Heptachlor epoxide...........  GC                                 608  6630 B & C...............  D3086-90................  Note 3, p. 7; note 4, p.
                                                                                                                                 30; note 6, p. S73;    
                                                                                                                                 note 8.                
                                   GC/MS                              625  6410 B...................  ........................  ........................
                                                                                                                                                        
42. Isodrin......................  GC                         ...........  .........................  ........................  Note 4, p. 30; Note 6,  
                                                                                                                                 p. S73.                
43. Linuron......................  GC                         ...........  .........................  ........................  Note 3, p. 104; Note 6, 
                                                                                                                                 p. S64.                
44. Malathion....................  GC                         ...........  6630 C...................  ........................  Note 3, p. 25; Note 4,  
                                                                                                                                 p. 30; Note 6, p. S51. 
45. Methiocarb...................  TLC                        ...........  .........................  ........................  Note 3, p. 94; Note 6,  
                                                                                                                                 p. S60.                
46. Methoxychlor.................  GC                         ...........  6630 B & C...............  D3086-90................  Note 3, p. 7; note 4, p.
                                                                                                                                 30; note 8.            
                                                                                                                                                        
47. Mexacarbate..................  TLC                        ...........  .........................  ........................  Note 3, p. 94; Note 6,  
                                                                                                                                 p. S60.                
48. Mirex........................  GC                         ...........  6630 B & C...............  ........................  Note 3, p. 7.           
49. Monuron......................  TLC                        ...........  .........................  ........................  Note 3, p. 104; Note 6, 
                                                                                                                                 p. S64.                
50. Monuron......................  TLC                        ...........  .........................  ........................  Note 3, p. 104; Note 6, 
                                                                                                                                 p. S64.                
51. Nuburon......................  TLC                        ...........  .........................  ........................  Note 3, p. 104; Note 6, 
                                                                                                                                 p. S64.                
52. Parathion methyl.............  GC                         ...........  6630 C...................  ........................  Note 3, p. 25; Note 4,  
                                                                                                                                 p. 30.                 
53. Parathion ethyl..............  GC                         ...........  6630 C...................  ........................  Note 3, p. 25.          
54. PCNB.........................  GC                         ...........  6630 B & C...............  ........................  Note 3, p. 7.           

[[Page 21]]

                                                                                                                                                        
55. Perthane.....................  GC                         ...........  .........................  D3086-90................  ........................
56. Prometron....................  GC                         ...........  .........................  ........................  Note 3, p. 83; Note 6,  
                                                                                                                                 p. S68.                
57. Prometryn....................  GC                         ...........  .........................  ........................  Note 3, p. 83; Note 6,  
                                                                                                                                 p. S68.                
58. Propazine....................  GC                         ...........  .........................  ........................  Note 3, p. 83; Note 6,  
                                                                                                                                 p. S68.                
59. Propham......................  TLC                        ...........  .........................  ........................  Note 3, p. 104; Note 6, 
                                                                                                                                 p. S64.                
60. Propoxur.....................  TLC                        ...........  .........................  ........................  Note 3, p. 94; Note 6,  
                                                                                                                                 p. S60.                
61. Secbumeton...................  TLC                        ...........  .........................  ........................  Note 3, p. 83; Note 6,  
                                                                                                                                 p. S68.                
62. Siduron......................  TLC                        ...........  .........................  ........................  Note 3, p. 104; Note 6, 
                                                                                                                                 p. S64.                
63. Simazine.....................  GC                         ...........  .........................  ........................  Note 3, p. 83; Note 6,  
                                                                                                                                 p. S68.                
64. Strobane.....................  GC                         ...........  6630 B & C...............  ........................  Note 3, p. 7.           
65. Swep.........................  TLC                        ...........  .........................  ........................  Note 3, p. 104; Note 6, 
                                                                                                                                 p. S64.                
66. 2,4,5-T......................  GC                         ...........  6640 B...................  ........................  Note 3, p. 115; Note 4, 
                                                                                                                                 p. 35.                 
67. 2,4,5-TP (Silvex)............  GC                         ...........  6640 B...................  ........................  Note 3, p. 115          
68. Terbuthylazine...............  GC                         ...........  .........................  ........................  Note 3, p. 83; Note 6,  
                                                                                                                                 p. S68.                
69. Toxaphene....................  GC                                 608  6630 B & C...............  D3086-90................  Note 3, p. 7; note 4, p.
                                                                                                                                 30; note 8.            
                                   GC/MS                              625  6410 B...................  ........................  ........................
70. Trifluralin..................  GC                         ...........  6630 B...................  ........................  Note 3, p. 7.           
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table ID notes:                                                                                                                                         
\1\ Pesticides are listed in this table by common name for the convenience of the reader. Additional pesticides may be found under Table 1C, where      
  entries are listed by chemical name.                                                                                                                  
\2\ The full text of Methods 608 and 625 are given at Appendix A. ``Test Procedures for Analysis of Organic Pollutants,'' of this Part 136. The         
  standardized test procedure to be used to determine the method detection limit (MDL) for these test procedures is given at Appendix B. ``Definition   
  and Procedure for the Determination of the Method Detection Limit'', of this Part 136.                                                                
\3\ ``Methods for Benzidine, Chlorinated Organic Compounds, Pentachlorophenol and Pesticides in Water and Wastewater,'' U.S. Environmental Protection   
  Agency, September, 1978. This EPA publication includes thin-layer chromatography (TLC) methods.                                                       
\4\ ``Methods for Analysis of Organic Substances in Water and Fluvial Sediments,'' Techniques of Water-Resources Investigations of the U.S. Geological  
  Survey, Book 5, Chapter A3 (1987).                                                                                                                    
\5\ The method may be extended to include -BHC, -BHC, endosulfan I, endosulfan II, and endrin. However, when they are known to exist, 
  Method 608 is the preferred method.                                                                                                                   
\6\ ``Selected Analytical Methods Approved and Cited by the United States Environmental Protection Agency.'' Supplement to the Fifteenth Edition of     
  Standard Methods for the Examination of Water and Wastewater (1981).                                                                                  
\7\ Each analyst must make an initial, one-time, demonstration of their ability to generate acceptable precision and accuracy with Methods 608 and 625  
  (See Appendix A of this Part 136) in accordance with procedures given in section 8.2 of each of these methods. Additionally, each laboratory, on an-  
  going basis, must spike and analyze 10% of all samples analyzed with Method 608 or 5% of all samples analyzed with Method 625 to monitor and evaluate 
  laboratory data quality in accordance with Sections 8.3 and 8.4 of these methods. When the recovery of any parameter falls outside the warning limits,
  the analytical results for that parameter in the unspiked sample are suspect and cannot be reported to demonstrate regulatory compliance. These       
  quality control requirements also apply to the Standard Methods, ASTM Methods, and other Methods cited.                                               
Note: These warning limits are promulgated as an ``Interim final action with a request for comments.''                                                  
\8\ ``Organochlorine Pesticides and PCBs in Wastewater Using EmporeTM Disk'', 3M Corporation, Revised 10/28/94.                                         


[[Page 22]]


                                                 Table IE.--List of Approved Radiologic Test Procedures                                                 
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Reference (method number or page)                             
                                                           ---------------------------------------------------------------------------------------------
       Parameter and units                 Method                                     Standard methods                                                  
                                                                    EPA\1\                18th Ed.                ASTM                  USGS \2\        
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. Alpha-Total, pCi per liter...  Proportional or           900...................  7110 B                D1943-90              pp. 75 and 78.\3\       
                                   scintillation counter.                                                                                               
2. Alpha-Counting error, pCi per  Proportional or           Appendix B............  7110 B                D1943-90              P. 79.                  
 liter.                            scintillation counter.                                                                                               
3. Beta-Total, pCi per liter....  Proportional counter....  900.0.................  7110 B                D1890-90              pp. 75 and 78.\3\       
4. Beta-Counting error, pCi.....  Proportional counter....  Appendix B............  7110 B                D1890-90              p. 79.                  
5. (a) Radium Total pCi per       Proportional counter....  903.0.................  7500Ra B              D2460-90                                      
 liter.                                                                                                                                                 
  (b)Ra, pCi per liter..........  Scintillation counter...  903.1.................  7500Ra C              D3454-91              p. 81.                  
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table IE notes:                                                                                                                                         
\1\ Prescribed Procedures for Measurement of Radioactivity in Drinking Water,'' EPA-600/4-80-032 (1980), U.S. Environmental Protection Agency, August   
  1980.                                                                                                                                                 
\2\ Fishman, M.J. and Brown, Eugene,'' Selected Methods of the U.S. Geological Survey of Analysis of Wastewaters,'' U.S. Geological Survey, Open-File   
  Report 76-177 (1976).                                                                                                                                 
\3\ The method found on p. 75 measures only the dissolved portion while the method on p. 78 measures only the suspended portion. Therefore, the two     
  results must be added to obtain the ``total''.                                                                                                        


[[Page 23]]

    (b) The full texts of the methods from the following references 
which are cited in Tables IA, IB, IC, ID, and IE are incorporated by 
reference into this regulation and may be obtained from the sources 
identified. All costs cited are subject to change and must be verified 
from the indicated sources. The full texts of all the test procedures 
cited are available for inspection at the Environmental Monitoring 
Systems Laboratory, Office of Research and Development, U.S. 
Environmental Protection Agency, 26 West Martin Luther King Dr., 
Cincinnati, OH 45268 and the Office of the Federal Register, room 8301, 
1110 L Street, NW., Washington, DC 20408.

            References, Sources, Costs, and Table Citations:

    (1) The full text of Methods 601-613, 624, 625, 1624, and 1625 are 
printed in appendix A of this part 136. The full text for determining 
the method detection limit when using the test procedures is given in 
appendix B of this part 136. The full text of Method 200.7 is printed in 
appendix C of this part 136. Cited in: Table IB, Note 5; Table IC, Note 
2; and Table ID, Note 2.
    (2) USEPA. 1978. Microbiological Methods for Monitoring the 
Environment, Water, and Wastes. Environmental Monitoring and Support 
Laboratory, U.S. Environmental Protection Agency, Cincinnati, Ohio. EPA/
600/8-78/017. Available from: National Technical Information Service, 
5285 Port Royal Road, Springfield, Virginia 22161, Publ. No. PB-290329/
AS. Cost: $36.95. Table IA, Note 3.
    (3) ``Methods for Chemical Analysis of Water and Wastes,'' U.S. 
Environmental Protection Agency, EPA-600/4-79-020, March 1979, or 
``Methods for Chemical Analysis of Water and Wastes,'' U.S. 
Environmental Protection Agency, EPA-600/4-79-020, Revised March 1983. 
Available from: ORD Publications, CERI, U.S. Environmental Protection 
Agency, Cincinnati, Ohio 45268, Table IB, Note 1.
    (4) ``Methods for Benzidine, Chlorinated Organic Compounds, 
Pentachlorophenol and Pesticides in Water and Wastewater,'' U.S. 
Environmental Protection Agency, 1978. Available from: ORD Publications, 
CERI, U.S. Environmental Protection Agency, Cincinnati, Ohio 45268, 
Table IC, Note 3; Table D, Note 3.
    (5) ``Prescribed Procedures for Measurement of Radioactivity in 
Drinking Water,'' U.S. Environmental Protection Agency, EPA-600/4-80-
032, 1980. Available from: ORD Publications, CERI, U.S. Environmental 
Protection Agency, Cincinnati, Ohio 45268, Table IE, Note 1.
    (6) American Public Health Association. 1992. Standard Methods for 
the Examination of Water and Wastewater. 18th Edition. Amer. Publ. Hlth. 
Assoc., 1015 15th Street NW, Washington, DC 20005. Cost: $160.00. Table 
IA, Note 4.
    (7) Ibid, 15th Edition, 1980. Table IB, Note 30; Table ID.
    (8) Ibid, 14th Edition, 1975. Table IB, Notes 17 and 27.
    (9) ``Selected Analytical Methods Approved and Cited by the United 
States Environmental Protection Agency,'' Supplement to the 15th Edition 
of Standard Methods for the Examination of Water and Wastewater, 1981. 
Available from: American Public Health Association, 1015 Fifteenth 
Street NW., Washington, DC 20036. Cost available from publisher. Table 
IB, Note 10; Table IC, Note 6; Table ID, Note 6.
    (10) Annual Book of ASTM Standards, Water and Environmental 
Technology, Section 11, Volumes 11.01 and 11.02, 1994 in 40 CFR 136.3, 
Tables IB, IC, ID and IE.
    (11) USGS. 1989. U.S. Geological Survey Techniques of Water-
Resources Investigations, Book 5, Laboratory Analysis, Chapter A4, 
Methods for Collection and Analysis of Aquatic Biological and 
Microbiological Samples, U.S. Geological Survey, U.S. Department of the 
Interior, Reston, Virginia. Available from: USGS Books and Open-File 
Reports Section, Federal Center, Box 25425, Denver, Colorado 80225. 
Cost: $18.00. Table IA, Note 5.
    (12) ``Methods for Determination of Inorganic Substances in Water 
and Fluvial Sediments,'' by M.J. Fishman and Linda C. Friedman, 
Techniques of Water-Resources Investigations of the U.S. Geological 
Survey, Book 5 Chapter A1 (1989). Available from: U.S. Geological 
Survey, Denver Federal Center, Box 25425, Denver, CO 80225. Cost: 
$108.75 (subject to change). Table IB, Note 2.

[[Page 24]]

    (13) ``Methods for Determination of Inorganic Substances in Water 
and Fluvial Sediments,'' N.W. Skougstad and others, editors. Techniques 
of Water-Resources Investigations of the U.S. Geological Survey, Book 5, 
Chapter A1 (1979). Available from: U.S. Geological Survey, Denver 
Federal Center, Box 25425, Denver, CO 80225. Cost: $10.00 (subject to 
change), Table IB, Note 8.
    (14) ``Methods for the Determination of Organic Substances in Water 
and Fluvial Sediments,'' Wershaw, R.L., et al, Techniques of Water-
Resources Investigations of the U.S. Geological Survey, Book 5, Chapter 
A3 (1987). Available from: U.S. Geological Survey, Denver Federal 
Center, Box 25425, Denver, CO 80225. Cost: $0.90 (subject to change). 
Table IB, Note 24; Table ID, Note 4.
    (15) ``Water Temperature--Influential Factors, Field Measurement and 
Data Presentation,'' by H.H. Stevens, Jr., J. Ficke, and G.F. Smoot, 
Techniques of Water-Resources Investigations of the U.S. Geological 
Survey, Book 1, Chapter D1, 1975. Available from: U.S. Geological 
Survey, Denver Federal Center, Box 25425, Denver, CO 80225. Cost: $1.60 
(subject to change). Table IB, Note 32.
    (16) ``Selected Methods of the U.S. Geological Survey of Analysis of 
Wastewaters,'' by M.J. Fishman and Eugene Brown; U.S. Geological Survey 
Open File Report 76-77 (1976). Available from: U.S. Geological Survey, 
Branch of Distribution, 1200 South Eads Street, Arlington, VA 22202. 
Cost: $13.50 (subject to change). Table IE, Note 2.
    (17) ``Official Methods of Analysis of the Association of Official 
Analytical Chemicals'', Methods manual, 15th Edition (1990). Price: 
$240.00. Available from: The Association of Official Analytical 
Chemists, 2200 Wilson Boulevard, Suite 400, Arlington, VA 22201. Table 
IB, Note 3.
    (18) ``American National Standard on Photographic Processing 
Effluents,'' April 2, 1975. Available from: American National Standards 
Institute, 1430 Broadway, New York, New York 10018. Table IB, Note 9.
    (19) ``An Investigation of Improved Procedures for Measurement of 
Mill Effluent and Receiving Water Color,'' NCASI Technical Bulletin No. 
253, December 1971. Available from: National Council of the Paper 
Industry for Air and Stream Improvements, Inc., 260 Madison Avenue, New 
York, NY 10016. Cost available from publisher. Table IB, Note 18.
    (20) Ammonia, Automated Electrode Method, Industrial Method Number 
379-75WE, dated February 19, 1976. Technicon Auto Analyzer II. Method 
and price available from Technicon Industrial Systems, Tarrytown, New 
York 10591. Table IB, Note 7.
    (21) Chemical Oxygen Demand, Method 8000, Hach Handbook of Water 
Analysis, 1979. Method price available from Hach Chemical Company, P.O. 
Box 389, Loveland, Colorado 80537. Table IB, Note 14.
    (22) OIC Chemical Oxygen Demand Method, 1978. Method and price 
available from Oceanography International Corporation, 512 West Loop, 
P.O. Box 2980, College Station, Texas 77840. Table IB, Note 13.
    (23) ORION Research Instruction Manual, Residual Chlorine Electrode 
Model 97-70, 1977. Method and price available from ORION Research 
Incorporation, 840 Memorial Drive, Cambridge, Massachusetts 02138. Table 
IB, Note 16.
    (24) Bicinchoninate Method for Copper. Method 8506, Hach Handbook of 
Water Analysis, 1979, Method and price available from Hach Chemical 
Company, P.O. Box 300, Loveland, Colorado 80537. Table IB, Note 19.
    (25) Hydrogen Ion (pH) Automated Electrode Method, Industrial Method 
Number 378-75WA. October 1976. Bran & Luebbe (Technicon) Auto Analyzer 
II. Method and price available from Bran & Luebbe Analyzing 
Technologies, Inc. Elmsford, N.Y. 10523. Table IB, Note 21.
    (26) 1,10-Phenanthroline Method using FerroVer Iron Reagent for 
Water, Hach Method 8008, 1980. Method and price available from Hach 
Chemical Company, P.O. Box 389 Loveland, Colorado 80537. Table IB, Note 
22.
    (27) Periodate Oxidation Method for Manganese, Method 8034, Hach 
Handbook for Water Analysis, 1979. Method and price available from Hach 
Chemical Company, P.O. Box 389, Loveland, Colorado 80537. Table IB, Note 
23.
    (28) Nitrogen, Nitrite--Low Range, Diazotization Method for Water 
and Wastewater, Hach Method 8507, 1979.

[[Page 25]]

Method and price available from Hach Chemical Company, P.O. Box 389, 
Loveland, Colorado 80537. Table IB, Note 25.
    (29) Zincon Method for Zinc, Method 8009. Hach Handbook for Water 
Analysis, 1979. Method and price available from Hach Chemical Company, 
P.O. Box 389, Loveland, Colorado 80537. Table IB, Note 33.
    (30) ``Direct Determination of Elemental Phosphorus by Gas-Liquid 
Chromatography,'' by R.F. Addison and R.G. Ackman, Journal of 
Chromatography, Volume 47, No. 3, pp. 421-426, 1970. Available in most 
public libraries. Back volumes of the Journal of Chromatography are 
available from Elsevier/North-Holland, Inc., Journal Information Centre, 
52 Vanderbilt Avenue, New York, NY 10164. Cost available from publisher. 
Table IB, Note 28.
    (31) ``Direct Current Plasma (DCP) Optical Emission Spectrometric 
Method for Trace Elemental Analysis of Water and Wastes'', Method AES 
0029, 1986-Revised 1991, Fison Instruments, Inc., 32 Commerce Center, 
Cherry Hill Drive, Danvers, MA 01923. Table B, Note 34.
    (32) ``Closed Vessel Microwave Digestion of Wastewater Samples for 
Determination of Metals, CEM Corporation, P.O. Box 200, Matthews, North 
Carolina 28106-0200, April 16, 1992. Available from the CEM Corporation. 
Table IB, Note 36.
    (33) ``Organochlorine Pesticides and PCBs in Wastewater Using Empore 
TM Disk'' Test Method 3M 0222, Revised 10/28/94. 3M Corporation, 3M 
Center Building 220-9E-10, St. Paul, MN 55144-1000. Method available 
from 3M Corporation. Table IC, Note 8 and Table ID, Note 8.
    (34) USEPA. 1993. Methods for Measuring the Acute Toxicity of 
Effluents to Freshwater and Marine Organisms. Fourth Edition, December 
1993. Environmental Monitoring Systems Laboratory, U.S. Environmental 
Protection Agency, Cincinnati, Ohio (EPA/600/4-90/027F). Available from: 
National Technical Information Service, 5285 Port Royal Road, 
Springfield, Virginia 22161, Publ. No. PB-91-167650. Cost: $31.00. Table 
IA, Note 17. See changes in the manual, listed in Part V of this rule.
    (35) ``Nitrogen, Total Kjeldahl, Method PAI-DK01 (Block Digestion, 
Steam Distillation, Titrimetric Detection)'', revised 12/22/94. 
Available from Perstorp Analytical Corporation, 9445 SW Ridder Rd., 
Suite 310, P.O. Box 648, Wilsonville, OK 97070. Table IB, Note 39.
    (36) ``Nitrogen, Total Kjeldahl, Method PAI-DK02 (Block Digestion, 
Steam Distillation, Colorimetric Detection)'', revised 12/22/94. 
Available from Perstorp Analytical Corporation, 9445 SW Ridder Rd., 
Suite 310, P.O. Box 648, Wilsonville, OK 97070. Table IB, Note 40.
    (37) ``Nitrogen, Total Kjeldahl, Method PAI-DK03 (Block Digestion, 
Automated FIA Gas Diffusion)'', revised 12/22/94. Available from 
Perstorp Analytical Corporation, 9445 SW Ridder Rd., Suite 310, P.O. Box 
648, Wilsonville, OK 97070. Table IB, Note 41.
    (38) USEPA. 1994. Short-term Methods for Estimating the Chronic 
Toxicity of Effluents and Receiving Waters to Freshwater Organisms. 
Third Edition. July 1994. Environmental Monitoring Systems Laboratory, 
U.S. Environmental Protection Agency, Cincinnati, Ohio. (EPA/600/4-91/
002). Available from: National Technical Information Service, 5285 Port 
Royal Road, Springfield, Virginia 22161, Publ. No. PB-92-139492. Cost: 
$31.00. Table IA, Note 8.
    (39) USEPA. 1994. Short-term Methods for Estimating the Chronic 
Toxicity of Effluents and Receiving Waters to Marine and Estuarine 
Organisms. Second Edition, July 1994. Environmental Monitoring Systems 
Laboratory, U.S. Environmental Protection Agency, Cincinnati, Ohio. EPA/
600/4-91/003. Available from: National Technical Information Service, 
5285 Port Royal Road, Springfield, Virginia 22161, Publ. No. PB-92-
139484. Cost: $45.00. Table IA, Note 9.
    (c) Under certain circumstances the Regional Administrator or the 
Director in the Region or State where the discharge will occur may 
determine for a particular discharge that additional parameters or 
pollutants must be reported. Under such circumstances, additional test 
procedures for analysis of pollutants may be specified by the Regional 
Administrator, or the Director

[[Page 26]]

upon the recommendation of the Director of the Environmental Monitoring 
Systems Laboratory--Cincinnati.
    (d) Under certain circumstances, the Administrator may approve, upon 
recommendation by the Director, Environmental Monitoring Systems 
Laboratory--Cincinnati, additional alternate test procedures for 
nationwide use.
    (e) Sample preservation procedures, container materials, and maximum 
allowable holding times for parameters cited in Tables IA, IB, IC, ID, 
and IE are prescribed in Table II. Any person may apply for a variance 
from the prescribed preservation techniques, container materials, and 
maximum holding times applicable to samples taken from a specific 
discharge. Applications for variances may be made by letters to the 
Regional Administrator in the Region in which the discharge will occur. 
Sufficient data should be provided to assure such variance does not 
adversely affect the integrity of the sample. Such data will be 
forwarded, by the Regional Administrator, to the Director of the 
Environmental Monitoring Systems Laboratory--Cincinnati, Ohio for 
technical review and recommendations for action on the variance 
application. Upon receipt of the recommendations from the Director of 
the Environmental Monitoring Systems Laboratory, the Regional 
Administrator may grant a variance applicable to the specific charge to 
the applicant. A decision to approve or deny a variance will be made 
within 90 days of receipt of the application by the Regional 
Administrator.

                    Table II--Required Containers, Preservation Techniques, and Holding Times                   
----------------------------------------------------------------------------------------------------------------
       Parameter No./name           Container \1\          Preservation \2\,\3\         Maximum holding time \4\
----------------------------------------------------------------------------------------------------------------
Table IA--Bacteria Tests:                                                                                       
  1-4 Coliform, fecal and total.  P,G..............  Cool, 4C, 0.008% Na2S2O3 5......  6 hours.                 
  5 Fecal streptococci..........  P,G..............  Cool, 4C, 0.008% Na2S2O3 5......  6 hours.                 
Table IA--Aquatic Toxicity                                                                                      
 Tests:                                                                                                         
  6-10 Toxicity, acute and        P,G..............  Cool, 4C \16\...................  6 hours.                 
   chronic.                                                                                                     
                                                                                                                
Table IB--Inorganic Tests:                                                                                      
  1. Acidity....................  P, G.............  Cool, 4C........................  14 days.                 
  2. Alkalinity.................  P, G.............  ......do........................      Do.                  
  4. Ammonia....................  P, G.............  Cool, 4C, H2SO4 to pH<2.........  28 days.                 
  9. Biochemical oxygen demand..  P, G.............  Cool, 4C........................  48 hours.                
  10. Boron.....................  P, PFTE, or        HNO3 TO pH<2....................  6 months.                
                                   Quartz.                                                                      
  11. Bromide...................  P, G.............  None required...................  28 days.                 
  14. Biochemical oxygen demand,  P, G.............  Cool, 4C........................  48 hours.                
   carbonaceous.                                                                                                
  15. Chemical oxygen demand....  P, G.............  Cool, 4C, H2SO4 to pH<2.........  28 days.                 
  16. Chloride..................  P, G.............  None required...................      Do.                  
  17. Chlorine, total residual..  P, G.............  ......do........................  Analyze immediately.     
  21. Color.....................  P, G.............  Cool, 4C........................  48 hours.                
  23-24. Cyanide, total and       P, G.............  Cool, 4C, NaOH to pH>12, 0.6g     14 days.6                
   amenable to chlorination.                          ascorbic acid 5.                                          
  25. Fluoride..................  P................  None required...................  28 days.                 
  27. Hardness..................  P, G.............  HNO3 to pH<2, H2SO4 to pH<2.....  6 months.                
  28. Hydrogen ion (pH).........  P, G.............  None required...................  Analyze immediately.     
  31, 43. Kjeldahl and organic    P, G.............  Cool, 4C, H2SO4 to pH<2.........  28 days.                 
   nitrogen.                                                                                                    
Metals:7                                                                                                        
  18. Chromium VI...............  P, G.............  Cool, 4C........................  24 hours.                
  35. Mercury...................  P, G.............  HNO3 to pH<2....................  6 months.                
  3, 5-8, 12, 13, 19, 20, 22,                                                                                   
   26, 29, 30, 32-34, 36, 37,                                                                                   
   45, 47, 51, 52, 58-60, 62,                                                                                   
   63, 70-72, 74, 75. Metals,                                                                                   
   except boron, chromium VI and                                                                                
   mercury.                                                                                                     
  38. Nitrate...................  P, G.............  Cool, 4C........................  48 hours.                
  39. Nitrate-nitrite...........  P, G.............  Cool, 4C, H2SO4 to pH<2.........  28 days.                 
  40. Nitrite...................  P, G.............  Cool, 4C........................  48 hours.                
  41. Oil and grease............  G................  Cool to 4C, HCl or H2SO4 to pH<2  28 days.                 
  42. Organic Carbon............  P, G.............  Cool to 4  deg.C HC1 or H2SO4 or  28 days.                 
                                                      H3PO4, to pH<2.                                           
  44. Orthophosphate............  P, G.............  Filter immediately, Cool, 4C....  48 hours.                
  46. Oxygen, Dissolved Probe...  G Bottle and top.  None required...................  Analyze immediately.     
  47. Winkler...................  ......do.........  Fix on site and store in dark...  8 hours.                 
  48. Phenols...................  G only...........  Cool, 4C, H2SO4 to pH<2.........  28 days.                 

[[Page 27]]

                                                                                                                
  49. Phosphorus (elemental)....  G................  Cool, 4C........................  48 hours.                
  50. Phosphorus, total.........  P, G.............  Cool, 4C, H2SO4 to pH<2.........  28 days.                 
  53. Residue, total............  P, G.............  Cool, 4C........................  7 days.                  
  54. Residue, Filterable.......  P, G.............  ......do........................  7 days.                  
  55. Residue, Nonfilterable      P, G.............  ......do........................  7 days.                  
   (TSS).                                                                                                       
  56. Residue, Settleable.......  P, G.............  ......do........................  48 hours.                
  57. Residue, volatile.........  P, G.............  ......do........................  7 days.                  
  61. Silica....................  P, PFTE, or        Cool, 4  deg.C..................  28 days.                 
                                   Quartz.                                                                      
  64. Specific conductance......  P, G.............  ......do........................      Do.                  
  65. Sulfate...................  P, G.............  ......do........................      Do.                  
  66. Sulfide...................  P, G.............  Cool, 4C add zinc acetate plus    7 days.                  
                                                      sodium hydroxide to pH>9.                                 
  67. Sulfite...................  P, G.............  None required...................  Analyze immediately.     
  68. Surfactants...............  P ,G.............  Cool, 4C........................  48 hours.                
  69. Temperature...............  P, G.............  None required...................  Analyze.                 
  73. Turbidity.................  P, G.............  Cool, 4C........................  48 hours.                
Table IC--Organic Tests.\8\                                                                                     
  13, 18-20, 22, 24-28, 34-37,    G, Telflon-lined   Cool, 4C, 0.008% Na2S2O3.\5\....  14 days.                 
   39-43, 45-47, 56, 66, 88, 89,   septum.                                                                      
   92-95, 97. Purgeable                                                                                         
   Halocarbons.                                                                                                 
  6, 57, 90. Purgeable aromatic   ......do.........  Cool, 4C, 0.008% Na2S2O3\5\, HC1      Do.                  
   hydrocarbons.                                      to pH2\9\.                                                
  3, 4, Acrolein and              ......do.........  Cool, 4C, 0.008% Na2S2O3\5\;          Do.                  
   acrylonitrile.                                     Adjust pH to 4-5 \10\.                                    
  23, 30, 44, 49, 53, 67, 70,     G, Teflon-lined    Cool, 4C, 0.008% Na2S2O3\5\.....  7 days until extraction, 
   71, 83, 85, 96. Phenols \11\.   cap.                                                 40 days after           
                                                                                        extraction.             
  7, 38. Benzidines11...........  ......do.........  ......do........................  7 days until             
                                                                                        extraction.13           
  14, 17, 48, 50-52. Phthalate    ......do.........  Cool, 4C........................  7 days until extraction; 
   esters11.                                                                            40 days after           
                                                                                        extraction.             
  72-74. Nitrosamines11,14......  ......do.........  Cool, 4C, store in dark, 0.008%       Do.                  
                                                      Na2S2O35.                                                 
  76-82. PCBs11 acrylonitrile...  ......do.........  Cool, 4C........................      Do.                  
  54, 55, 65, 69. Nitroaromatics  ......do.........  Cool, 4C, 0.008% Na2S2O35 store       Do.                  
   and isophorone11.                                  in dark.                                                  
  1, 2, 5, 8-12, 32, 33, 58, 59,  ......do.........  ......do........................      Do.                  
   64, 68, 84, 86. Polynuclear                                                                                  
   aromatic hydrocarbons.\1\\1\.                                                                                
  15, 16, 21, 31, 75.             ......do.........  Cool, 4C, 0.008% Na2S2O35.......      Do.                  
   Haloethers11.                                                                                                
  29, 35-37, 60-63, 91.           ......do.........  Cool, 4C........................      Do.                  
   Chlorinated hydrocarbons\11\.                                                                                
  87. TCDD\11\..................  ......do.........  Cool, 4C, 0.008% Na2S2O35.......      Do.                  
Table ID--Pesticides Tests:                                                                                     
  1-70. Pesticides\11\..........  ......do.........  Cool, 4C, pH 5-915..............      Do.                  
Table IE--Radiological Tests:                                                                                   
  1-5. Alpha, beta and radium...  P, G.............  HNO3 to pH<2....................  6 months.                
----------------------------------------------------------------------------------------------------------------
Table II Notes                                                                                                  
                                                                                                                
\1\ Polyethylene (P) or glass (G). For microbiology, plastic sample containers must be made of sterilizable     
  materials (polypropylene or other autoclavable plastic).                                                      
2 Sample preservation should be performed immediately upon sample collection. For composite chemical samples    
  each aliquot should be preserved at the time of collection. When use of an automated sampler makes it         
  impossible to preserve each aliquot, then chemical samples may be preserved by maintaining at 4C until        
  compositing and sample splitting is completed.                                                                
3 When any sample is to be shipped by common carrier or sent through the United States Mails, it must comply    
  with the Department of Transportation Hazardous Materials Regulations (49 CFR part 172). The person offering  
  such material for transportation is responsible for ensuring such compliance. For the preservation            
  requirements of Table II, the Office of Hazardous Materials, Materials Transportation Bureau, Department of   
  Transportation has determined that the Hazardous Materials Regulations do not apply to the following          
  materials: Hydrochloric acid (HCl) in water solutions at concentrations of 0.04% by weight or less (pH about  
  1.96 or greater); Nitric acid (HNO3) in water solutions at concentrations of 0.15% by weight or less (pH about
  1.62 or greater); Sulfuric acid (H2SO4) in water solutions at concentrations of 0.35% by weight or less (pH   
  about 1.15 or greater); and Sodium hydroxide (NaOH) in water solutions at concentrations of 0.080% by weight  
  or less (pH about 12.30 or less).                                                                             
\4\ Samples should be analyzed as soon as possible after collection. The times listed are the maximum times that
  samples may be held before analysis and still be considered valid. Samples may be held for longer periods only
  if the permittee, or monitoring laboratory, has data on file to show that for the specific types of samples   
  under study, the analytes are stable for the longer time, and has received a variance from the Regional       
  Administrator under Sec.  136.3(e). Some samples may not be stable for the maximum time period given in the   
  table. A permittee, or monitoring laboratory, is obligated to hold the sample for a shorter time if knowledge 
  exists to show that this is necessary to maintain sample stability. See Sec.  136.3(e) for details. The term  
  ``analyze immediately'' usually means within 15 minutes or less of sample collection.                         
5 Should only be used in the presence of residual chlorine.                                                     
6 Maximum holding time is 24 hours when sulfide is present. Optionally all samples may be tested with lead      
  acetate paper before pH adjustments in order to determine if sulfide is present. If sulfide is present, it can
  be removed by the addition of cadmium nitrate powder until a negative spot test is obtained. The sample is    
  filtered and then NaOH is added to pH 12.                                                                     
7 Samples should be filtered immediately on-site before adding preservative for dissolved metals.               
8 Guidance applies to samples to be analyzed by GC, LC, or GC/MS for specific compounds.                        

[[Page 28]]

                                                                                                                
9 Sample receiving no pH adjustment must be analyzed within seven days of sampling.                             
10 The pH adjustment is not required if acrolein will not be measured. Samples for acrolein receiving no pH     
  adjustment must be analyzed within 3 days of sampling.                                                        
11 When the extractable analytes of concern fall within a single chemical category, the specified preservative  
  and maximum holding times should be observed for optimum safeguard of sample integrity. When the analytes of  
  concern fall within two or more chemical categories, the sample may be preserved by cooling to 4C, reducing   
  residual chlorine with 0.008% sodium thiosulfate, storing in the dark, and adjusting the pH to 6-9; samples   
  preserved in this manner may be held for seven days before extraction and for forty days after extraction.    
  Exceptions to this optional preservation and holding time procedure are noted in footnote 5 (re the           
  requirement for thiosulfate reduction of residual chlorine), and footnotes 12, 13 (re the analysis of         
  benzidine).                                                                                                   
12 If 1,2-diphenylhydrazine is likely to be present, adjust the pH of the sample to 4.00.2 to       
  prevent rearrangement to benzidine.                                                                           
13 Extracts may be stored up to 7 days before analysis if storage is conducted under an inert (oxidant-free)    
  atmosphere.                                                                                                   
14 For the analysis of diphenylnitrosamine, add 0.008% Na2S2O3 and adjust pH to 7-10 with NaOH within 24 hours  
  of sampling.                                                                                                  
15 The pH adjustment may be performed upon receipt at the laboratory and may be omitted if the samples are      
  extracted within 72 hours of collection. For the analysis of aldrin, add 0.008% Na2S2O3.                      
\16\ Sufficient ice should be placed with the samples in the shipping container to ensure that ice is still     
  present when the samples arrive at the laboratory. However, even if ice is present when the samples arrive, it
  is necessary to immediately measure the temperature of the samples and confirm that the 4C temperature maximum
  has not been exceeded. In the isolated cases where it can be documented that this holding temperature can not 
  be met, the permittee can be given the option of on-site testing or can request a variance. The request for a 
  variance should include supportive data which show that the toxicity of the effluent samples is not reduced   
  because of the increased holding temperature.                                                                 

[38 FR 28758, Oct. 16, 1973, as amended at 41 FR 52781, Dec. 1, 1976; 49 
FR 43251, 43258, 43259, Oct. 26, 1984; 50 FR 691, 692, 695, Jan. 4, 
1985; 51 FR 23693, June 30, 1986; 52 FR 33543, Sept. 3, 1987; 55 FR 
24534, June 15, 1990; 55 FR 33440, Aug. 15, 1990; 56 FR 50759, Oct. 8, 
1991; 57 FR 41833, Sept. 11, 1992; 58 FR 4505, Jan. 31, 1994; 60 FR 
17160, Apr. 4, 1995; 60 FR 39588, 39590, Aug. 2, 1995; 60 FR 44672, Aug. 
28, 1995; 60 FR 53542, 53543, Oct. 16, 1995]



Sec. 136.4   Application for alternate test procedures.

    (a) Any person may apply to the Regional Administrator in the Region 
where the discharge occurs for approval of an alternative test 
procedure.
    (b) When the discharge for which an alternative test procedure is 
proposed occurs within a State having a permit program approved pursuant 
to section 402 of the Act, the applicant shall submit his application to 
the Regional Administrator through the Director of the State agency 
having responsibility for issuance of NPDES permits within such State.
    (c) Unless and until printed application forms are made available, 
an application for an alternate test procedure may be made by letter in 
triplicate. Any application for an alternate test procedure under this 
paragraph (c) shall:
    (1) Provide the name and address of the responsible person or firm 
making the discharge (if not the applicant) and the applicable ID number 
of the existing or pending permit, issuing agency, and type of permit 
for which the alternate test procedure is requested, and the discharge 
serial number.
    (2) Identify the pollutant or parameter for which approval of an 
alternate testing procedure is being requested.
    (3) Provide justification for using testing procedures other than 
those specified in Table I.
    (4) Provide a detailed description of the proposed alternate test 
procedure, together with references to published studies of the 
applicability of the alternate test procedure to the effluents in 
question.
    (d) An application for approval of an alternate test procedure for 
nationwide use may be made by letter in triplicate to the Director, 
Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268. 
Any application for an alternate test procedure under this paragraph (d) 
shall:
    (1) Provide the name and address of the responsible person or firm 
making the application.
    (2) Identify the pollutant(s) or parameter(s) for which nationwide 
approval of an alternate testing procedure is being requested.
    (3) Provide a detailed description of the proposed alternate 
procedure, together with references to published or other studies 
confirming the general applicability of the alternate test procedure to 
the pollutant(s) or parameter(s) in waste water discharges from 
representative and specified industrial or other categories.
    (4) Provide comparability data for the performance of the proposed 
alternate test procedure compared to the

[[Page 29]]

performance of the approved test procedures.

[38 FR 28760, Oct. 16, 1973, as amended at 41 FR 52785, Dec. 1, 1976]



Sec. 136.5   Approval of alternate test procedures.

    (a) The Regional Administrator of the region in which the discharge 
will occur has final responsibility for approval of any alternate test 
procedure proposed by the responsible person or firm making the 
discharge.
    (b) Within thirty days of receipt of an application, the Director 
will forward such application proposed by the responsible person or firm 
making the discharge, together with his recommendations, to the Regional 
Administrator. Where the Director recommends rejection of the 
application for scientific and technical reasons which he provides, the 
Regional Administrator shall deny the application, and shall forward a 
copy of the rejected application and his decision to the Director of the 
State Permit Program and to the Director of the Environmental Monitoring 
and Support Laboratory, Cincinnati.
    (c) Before approving any application for an alternate test procedure 
proposed by the responsible person or firm making the discharge, the 
Regional Administrator shall forward a copy of the application to the 
Director of the Environmental Monitoring and Support Laboratory, 
Cincinnati.
    (d) Within ninety days of receipt by the Regional Administrator of 
an application for an alternate test procedure, proposed by the 
responsible person or firm making the discharge, the Regional 
Administrator shall notify the applicant and the appropriate State 
agency of approval or rejection, or shall specify the additional 
information which is required to determine whether to approve the 
proposed test procedure. Prior to the expiration of such ninety day 
period, a recommendation providing the scientific and other technical 
basis for acceptance or rejection will be forwarded to the Regional 
Administrator by the Director of the Environmental Monitoring and 
Support Laboratory, Cincinnati. A copy of all approval and rejection 
notifications will be forwarded to the Director, Environmental 
Monitoring and Support Laboratory, Cincinnati, for the purposes of 
national coordination.
    (e) Approval for nationwide use. (1) Within 60 days of the receipt 
by the Director of the Environmental Monitoring Systems Laboratory--
Cincinnati (EMSL-CI) of an application for an alternate test procedure 
for nationwide use, the Director of EMSL-CI shall notify the applicant 
in writing whether the application is complete. If the application is 
incomplete, the applicant shall be informed of the information necessary 
to make the application complete.
    (2) Within 90 days of the receipt of a complete package: EMSL-CI 
shall perform any analysis necessary to determine whether the alternate 
method satisfies the applicable requirements of this part; and the 
Director of EMSL-CI shall recommend to the Administrator that he/she 
approve or reject the application and shall also notify the applicant of 
such recommendation.
    (3) As expeditiously as practicable, an alternate method determined 
by the Administrator to satisfy the applicable requirements of this part 
shall be proposed by EPA for incorporation in subsection 136.3 of 40 CFR 
part 136. EPA shall make available for review all the factual bases for 
its proposal, including any performance data submitted by the applicant 
and any available EPA analysis of those data.
    (4) Following a period of public comment, EPA shall, as 
expeditiously as practicable, publish in the Federal Register a final 
decision to approve or reject the alternate method.

[38 FR 28760, Oct. 16, 1973, as amended at 41 FR 52785, Dec. 1, 1976; 55 
FR 33440, Aug. 15, 1990]

    Appendix A to Part 136--Methods for Organic Chemical Analysis of 
                   Municipal and Industrial Wastewater

                    Method 601--Purgeable Halocarbons

                        1. Scope and Application

    1.1  This method covers the determination of 29 purgeable 
halocarbons.
    The following parameters may be determined by this method:

[[Page 30]]



------------------------------------------------------------------------
                                                  STORET                
                   Parameter                       No.        CAS No.   
------------------------------------------------------------------------
Bromodichloromethane...........................    32101         75-27-4
Bromoform......................................    32104         75-25-2
Bromomethane...................................    34413         74-83-9
Carbon tetrachloride...........................    32102         56-23-5
Chlorobenzene..................................    34301        108-90-7
Chloroethane...................................    34311         75-00-3
2-Chloroethylvinyl ether.......................    34576        100-75-8
Chloroform.....................................    32106         67-66-3
Chloromethane..................................    34418         74-87-3
Dibromochloromethane...........................    32105        124-48-1
1,2-Dichlorobenzene............................    34536         95-50-1
1,3-Dichlorobenzene............................    34566        541-73-1
1,4-Dichlorobenzene............................    34571        106-46-7
Dichlorodifluoromethane........................    34668         75-71-8
1,1-Dichloroethane.............................    34496         75-34-3
1,2-Dichloroethane.............................    34531        107-06-2
1,1-Dichloroethane.............................    34501         75-35-4
trans-1,2-Dichloroethene.......................    34546        156-60-5
1,2-Dichloropropane............................    34541         78-87-5
cis-1,3-Dichloropropene........................    34704      10061-01-5
trans-1,3-Dichloropropene......................    34699      10061-02-6
Methylene chloride.............................    34423         75-09-2
1,1,2,2-Tetrachloroethane......................    34516         79-34-5
Tetrachloroethene..............................    34475        127-18-4
1,1,1-Trichloroethane..........................    34506         71-55-6
1,1,2-Trichloroethane..........................    34511         79-00-5
Tetrachloroethene..............................    39180         79-01-6
Trichlorofluoromethane.........................    34488         75-69-4
Vinyl chloride.................................    39715         75-01-4
------------------------------------------------------------------------

    1.2  This is a purge and trap gas chromatographic (GC) method 
applicable to the determination of the compounds listed above in 
municipal and industrial discharges as provided under 40 CFR 136.1. When 
this method is used to analyze unfamiliar samples for any or all of the 
compounds above, compound identifications should be supported by at 
least one additional qualitative technique. This method describes 
analytical conditions for a second gas chromatographic column that can 
be used to confirm measurements made with the primary column. Method 624 
provides gas chromatograph/mass spectrometer (GC/MS) conditions 
appropriate for the qualitative and quantitative confirmation of results 
for most of the parameters listed above.
    1.3  The method detection limit (MDL, defined in Section 12.1) 
1 for each parameter is listed in Table 1. The MDL for a specific 
wastewater may differ from those listed, depending upon the nature of 
interferences in the sample matrix.
    1.4  Any modification of this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5.
    1.5  This method is restricted to use by or under the supervision of 
analysts experienced in the operation of a purge and trap system and a 
gas chromatograph and in the interpretation of gas chromatograms. Each 
analyst must demonstrate the ability to generate acceptable results with 
this method using the procedure described in Section 8.2.

                          2. Summary of Method

    2.1  An inert gas is bubbled through a 5-mL water sample contained 
in a specially-designed purging chamber at ambient temperature. The 
halocarbons are efficiently transferred from the aqueous phase to the 
vapor phase. The vapor is swept through a sorbent trap where the 
halocarbons are trapped. After purging is completed, the trap is heated 
and backflushed with the inert gas to desorb the halocarbons onto a gas 
chromatographic column. The gas chromatograph is temperature programmed 
to separate the halocarbons which are then detected with a halide-
specific detector.2\,\3
    2.2  The method provides an optional gas chromatographic column that 
may be helpful in resolving the compounds of interest from interferences 
that may occur.

                            3. Interferences

    3.1  Impurities in the purge gas and organic compounds outgassing 
from the plumbing ahead of the trap account for the majority of 
contamination problems. The analytical system must be demonstrated to be 
free from contamination under the conditions of the analysis by running 
laboratory reagent blanks as described in Section 8.1.3. The use of non-
Teflon plastic tubing, non-Teflon thread sealants, or flow controllers 
with rubber components in the purge and trap system should be avoided.
    3.2  Samples can be contaminated by diffusion of volatile organics 
(particularly fluorocarbons and methylene chloride) through the septum 
seal ilto the sample during shipment and storage. A field reagent blank 
prepared from reagent water and carried through the sampling and 
handling protocol can serve as a check on such contamination.
    3.3  Contamination by carry-over can occur whenever high level and 
low level samples are sequentially analyzed. To reduce carry-over, the 
purging device and sample syringe must be rinsed with reagent water 
between sample analyses. Whenever an unusually concentrated sample is 
encountered, it should be followed by an analysis of reagent water to 
check for cross contamination. For samples containing large amounts of 
water-soluble materials, suspended solids, high boiling compounds or 
high organohalide levels, it may be necessary to wash out the purging 
device with a detergent solution, rinse it with distilled water, and 
then dry it in a 105 deg.C oven between analyses. The trap and other 
parts of the system are also subject to contamination; therefore, 
frequent bakeout and purging of the entire system may be required.

                               4. Safety 

    4.1  The toxicity or carcinogenicity of each reagent used in this 
method has not

[[Page 31]]

been precisely defined; however, each chemical compound should be 
treated as a potential health hazard. From this viewpoint, exposure to 
these chemicals must be reduced to the lowest possible level by whatever 
means available. The laboratory is responsible for maintaining a current 
awareness file of OSHA regulations regarding the safe handling of the 
chemicals specified in this method. A reference file of material data 
handling sheets should also be made available to all personnel involved 
in the chemical analysis. Additional references to laboratory safety are 
available and have been identified 4-6 for the information of the 
analyst.
    4.2  The following parameters covered by this method have been 
tentatively classified as known or suspected, human or mammalian 
carcinogens: carbon tetrachloride, chloroform, 1,4-dichlorobenzene, and 
vinyl chloride. Primary standards of these toxic compounds should be 
prepared in a hood. A NIOSH/MESA approved toxic gas respirator should be 
worn when the analyst handles high concentrations of these toxic 
compounds.

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete sampling.
    5.1.1  Vial--25-mL capacity or larger, equipped with a screw cap 
with a hole in the center (Pierce 13075 or equivalent). Detergent wash, 
rinse with tap and distilled water, and dry at 105  deg.C before use.
    5.1.2  Septum--Teflon-faced silicone (Pierce 12722 or equivalent). 
Detergent wash, rinse with tap and distilled water, and dry at 105 
deg.C for 1 h before use.
    5.2  Purge and trap system--The purge and trap system consists of 
three separate pieces of equipment: a purging device, trap, and 
desorber. Several complete systems are now commercially available.
    5.2.1  The purging device must be designed to accept 5-mL samples 
with a water column at least 3 cm deep. The gaseous head space between 
the water column and the trap must have a total volume of less than 15 
mL. The purge gas must pass through the water column as finely divided 
bubbles with a diameter of less than 3 mm at the origin. The purge gas 
must be introduced no more than 5 mm from the base of the water column. 
The purging device illustrated in Figure 1 meets these design criteria.
    5.2.2  The trap must be at least 25 cm long and have an inside 
diameter of at least 0.105 in. The trap must be packed to contain the 
following minimum lengths of adsorbents: 1.0 cm of methyl silicone 
coated packing (Section 6.3.3), 7.7 cm of 2,6-diphenylene oxide polymer 
(Section 6.3.2), 7.7 cm of silica gel (Section 6.3.4), 7.7 cm of coconut 
charcoal (Section 6.3.1). If it is not necessary to analyze for 
dichlorodifluoromethane, the charcoal can be eliminated, and the polymer 
section lengthened to 15 cm. The minimum specifications for the trap are 
illustrated in Figure 2.
    5.2.3  The desorber must be capable of rapidly heating the trap to 
180  deg.C. The polymer section of the trap should not be heated higher 
than 180  deg.C and the remaining sections should not exceed 200  deg.C. 
The desorber illustrated in Figure 2 meets these design criteria.
    5.2.4  The purge and trap system may be assembled as a separate unit 
or be coupled to a gas chromatograph as illustrated in Figures 3 and 4.
    5.3  Gas chromatograph--An analytical system complete with a 
temperature programmable gas chromatograph suitable for on-column 
injection and all required accessories including syringes, analytical 
columns, gases, detector, and strip-chart recorder. A data system is 
recommended for measuring peak areas.
    5.3.1  Column 1--8 ft long x 0.1 in. ID stainless steel or glass, 
packed with 1% SP-1000 on Carbopack B (60/80 mesh) or equivalent. This 
column was used to develop the method performance statements in Section 
12. Guidelines for the use of alternate column packings are provided in 
Section 10.1.
    5.3.2  Column 2--6 ft long x 0.1 in. ID stainless steel or glass, 
packed with chemically bonded n-octane on Porasil-C (100/120 mesh) or 
equivalent.
    5.3.3  Detector--Electrolytic conductivity or microcoulometric 
detector. These types of detectors have proven effective in the analysis 
of wastewaters for the parameters listed in the scope (Section 1.1). The 
electrolytic conductivity detector was used to develop the method 
performance statements in Section 12. Guidelines for the use of 
alternate detectors are provided in Section 10.1.
    5.4  Syringes--5-mL glass hypodermic with Luerlok tip (two each), if 
applicable to the purging device.
    5.5  Micro syringes--25-L, 0.006 in. ID needle.
    5.6  Syringe valve--2-way, with Luer ends (three each).
    5.7  Syringe--5-mL, gas-tight with shut-off valve.
    5.8  Bottle--15-mL, screw-cap, with Teflon cap liner.
    5.9  Balance--Analytical, capable of accurately weighing 0.0001 g.

                               6. Reagents

    6.1  Reagent water--Reagent water is defined as a water in which an 
interferent is not observed at the MDL of the parameters of interest.
    6.1.1  Reagent water can be generated by passing tap water through a 
carbon filter bed containing about 1 lb of activated carbon (Filtrasorb-
300, Calgon Corp., or equivalent).

[[Page 32]]

    6.1.2  A water purification system (Millipore Super-Q or equivalent) 
may be used to generate reagent water.
    6.1.3  Reagent water may also be prepared by boiling water for 15 
min. Subsequently, while maintaining the temperature at 90  deg.C, 
bubble a contaminant-free inert gas through the water for 1 h. While 
still hot, transfer the water to a narrow mouth screw-cap bottle and 
seal with a Teflon-lined septum and cap.
    6.2  Sodium thiosulfate--(ACS) Granular.
    6.3  Trap Materials:
    6.3.1  Coconut charcoal--6/10 mesh sieved to 26 mesh, Barnabey 
Cheney, CA-580-26 lot  M-2649 or equivalent.
    6.3.2  2,6-Diphenylene oxide polymer--Tenax, (60/80 mesh), 
chromatographic grade or equivalent.
    6.3.3  Methyl silicone packing--3% OV-1 on Chromosorb-W (60/80 mesh) 
or equivalent.
    6.3.4  Silica gel--35/60 mesh, Davison, grade-15 or equivalent.
    6.4  Methanol--Pesticide quality or equivalent.
    6.5  Stock standard solutions--Stock standard solutions may be 
prepared from pure standard materials or purchased as certified 
solutions. Prepare stock standard solutions in methanol using assayed 
liquids or gases as appropriate. Because of the toxicity of some of the 
organohalides, primary dilutions of these materials should be prepared 
in a hood. A NIOSH/MESA approved toxic gas respirator should be used 
when the analyst handles high concentrations of such materials.
    6.5.1  Place about 9.8 mL of methanol into a 10-mL ground glass 
stoppered volumetric flask. Allow the flask to stand, unstoppered, for 
about 10 min or until all alcohol wetted surfaces have dried. Weigh the 
flask to the learest 0.1 mg.
    6.5.2  Add the assayed reference material:
    6.5.2.1  Liquid--Using a 100 L syringe, immediately add two 
or more drops of assayed reference material to the flask, then reweigh. 
Be sure that the drops fall directly into the alcohol without contacting 
the neck of the flask.
    6.5.2.2  Gases--To prepare standards for any of the six halocarbons 
that boil below 30  deg. C (bromomethane, chloroethane, chloromethane, 
dichlorodifluoromethane, trichlorofluoromethane, vinyl chloride), fill a 
5-mL valved gas-tight syringe with the reference standard to the 5.0-mL 
mark. Lower the needle to 5 mm above the methanol meniscus. Slowly 
introduce the reference standard above the surface of the liquid (the 
heavy gas will rapidly dissolve into the methanol).
    6.5.3  Reweigh, dilute to volume, stopper, then mix by inverting the 
flask several times. Calculate the concentration in g/
L from the net gain in weight. When compound purity is assayed 
to be 96% or greater, the weight can be used without correction to 
calculate the concentration of the stock standard. Commercially prepared 
stock standards can be used at any concentration if they are certified 
by the malufacturer or by an independent source.
    6.5.4  Transfer the stock standard solution into a Teflon-sealed 
screw-cap bottle. Store, with minimal headspace, at -10 to -20  deg.C 
and protect from light.
    6.5.5  Prepare fresh standards weekly for the six gases and 2-
chloroethylvinyl ether. All other standards must be replaced after one 
month, or sooner if comparison with check standards indicates a problem.
    6.6  Secondary dilution standards--Using stock standard solutions, 
prepare secondary dilution standards in methanol that contain the 
compounds of interest, either singly or mixed together. The secondary 
dilution standards should be prepared at concentrations such that the 
aqueous calibration standards prepared in Section 7.3.1 or 7.4.1 will 
bracket the working range of the analytical system. Secondary dilution 
standards should be stored with minimal headspace and should be checked 
frequently for signs of degradation or evaporation, especially just 
prior to preparing calibration standards from them.
    6.7  Quality control check sample concentrate--See Section 8.2.1.

                             7. Calibration

    7.1  Assemble a purge and trap system that meets the specifications 
in Section 5.2. Condition the trap overnight at 180  deg.C by 
backflushing with an inert gas flow of at least 20 mL/min. Condition the 
trap for 10 min once daily prior to use.
    7.2  Connect the purge and trap system to a gas chromatograph. The 
gas chromatograph must be operated using temperature and flow rate 
conditions equivalent to those given in Table 1. Calibrate the purge and 
trap-gas chromatographic system using either the external standard 
technique (Section 7.3) or the internal standard technique (Section 
7.4).
    7.3  External standard calibration procedure:
    7.3.1  Prepare calibration standards at a miminum of three 
concentration levels for each parameter by carefully adding 20.0 
L of one or more secondary dilution standards to 100, 500, or 
1000 L of reagent water. A 25-L syringe with a 0.006 
in. ID needle should be used for this operation. One of the external 
standards should be at a concentration near, but above, the MDL (Table 
1) and the other concentrations should correspond to the expected range 
of concentrations found in real samples or should define the working 
range of the detector. These aqueous standards can be stored up to 24 h, 
if held in sealed vials with zero headspace as described in Section 9.2. 
If not so stored, they must be discarded after 1 h.

[[Page 33]]

    7.3.2  Analyze each calibration standard according to Section 10, 
and tabulate peak height or area responses versus the concentration in 
the standard. The results can be used to prepare a calibration curve for 
each compound. Alternatively, if the ratio of response to concentration 
(calibration factor) is a constant over the working range (<10% relative 
standard deviation, RSD), linearity through the origin can be assumed 
and the average ratio or calibration factor can be used in place of a 
calibration curve.
    7.4  Internal standard calibration procedure--To use this approach, 
the analyst must select one or more internal standards that are similar 
in analytical behavior to the compounds of interest. The analyst must 
further demonstrate that the measurement of the internal standard is not 
affected by method or matrix interferences. Because of these 
limitations, no internal standard can be suggested that is applicable to 
all samples. The compounds recommended for use as surrogate spikes in 
Section 8.7 have been used successfully as internal standards, because 
of their generally unique retention times.
    7.4.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest as described in 
Section 7.3.1.
    7.4.2  Prepare a spiking solution containing each of the internal 
standards using the procedures described in Sections 6.5 and 6.6. It is 
recommended that the secondary dilution standard be prepared at a 
concentration of 15 g/mL of each internal standard compound. 
The addition of 10 L of this standard to 5.0 mL of sample or 
calibration standard would be equivalent to 30 g/L.
    7.4.3  Analyze each calibration standard according to Section 10, 
adding 10 L of internal standard spiking solution directly to 
the syringe (Section 10.4). Tabulate peak height or area responses 
against concentration for each compound and internal standard, and 
calculate response factors (RF) for each compound using Equation 1.

                                                                        
                                          (As)(Cis)                     
                                    RF=  -----------                    
                                          (Ais)(Cs)                     
                                                                        

    Equation 1
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Cis=Concentration of the internal standard.
    Cs=Concentration of the parameter to be measured.

If the RF value over the working range is a constant (<10% RSD), the RF 
can be assumed to be invariant and the average RF can be used for 
calculations. Alternatively, the results can be used to plot a 
calibration curve of response ratios, As/Ais, vs. RF.
    7.5  The working calibration curve, calibration factor, or RF must 
be verified on each working day by the measurement of a QC check sample.
    7.5.1  Prepare the QC check sample as described in Section 8.2.2.
    7.5.2  Analyze the QC check sample according to Section 10.
    7.5.3  For each parameter, compare the response (Q) with the 
corresponding calibration acceptance criteria found in Table 2. If the 
responses for all parameters of interest fall within the designated 
ranges, analysis of actual samples can begin. If any individual Q falls 
outside the range, proceed according to Section 7.5.4.

    Note: The large number of parameters in Table 2 present a 
substantial probability that one or more will not meet the calibration 
acceptance criteria when all parameters are analyzed.

    7.5.4  Repeat the test only for those parameters that failed to meet 
the calibration acceptance criteria. If the response for a parameter 
does not fall within the range in this second test, a new calibration 
curve, calibration factor, or RF must be prepared for that parameter 
according to Section 7.3 or 7.4.

                           8. Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality control program. The minimum requirements of this program 
consist of an initial demonstration of laboratory capability and an 
ongoing analysis of spiked samples to evaluate and document data 
quality. The laboratory must maintain records to document the quality of 
data that is generated. Ongoing data quality checks are compared with 
established performance criteria to determine if the results of analyses 
meet the performance characteristics of the method. When results of 
sample spikes indicate atypical method performance, a quality control 
check standard must be analyzed to confirm that the measurements were 
performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occurring in 
chromatography, the analyst is permitted certain options (detailed in 
Section 10.1) to improve the separations or lower the cost of 
measurements. Each time such a modification is made to the method, the 
analyst is required to repeat the procedure in Section 8.2.
    8.1.3  Each day, the analyst must analyze a reagent water blank to 
demonstrate that interferences from the analytical system are under 
control.

[[Page 34]]

    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 10% of all samples to monitor and evaluate laboratory data 
quality. This procedure is described in Section 8.3.
    8.1.5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 10% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.5.
    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality control (QC) check sample concentrate is required 
containing each parameter of interest at a concentration of 10 
g/mL in methanol. The QC check sample concentrate must be 
obtained from the U.S. Environmental Protection Agency, Environmental 
Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If 
not available from that source, the QC check sample concentrate must be 
obtained from another external source. If not available from either 
source above, the QC check sample concentrate must be prepared by the 
laboratory using stock standards prepared independently from those used 
for calibration.
    8.2.2  Prepare a QC check sample to contain 20 g/L of each 
parameter by adding 200 L of QC check sample concentrate to 100 
mL of reagent water.
    8.2.3  Analyze four 5-mL aliquots of the well-mixed QC check sample 
according to Section 10.
    8.2.4  Calculate the average recovery (X) in g/L, and the 
standard deviation of the recovery (s) in g/L, for each 
parameter of interest using the four results.
    8.2.5  For each parameter compare s and X with the corresponding 
acceptance criteria for precision and accuracy, respectively, found in 
Table 2. If s and X for all parameters of interest meet the acceptance 
criteria, the system performance is acceptable and analysis of actual 
samples can begin. If any individual s exceeds the precision limit or 
any individual X falls outside the range for accuracy, then the system 
performance is unacceptable for that parameter.

    Note: The large number of parameters in Table 2 present a 
substantial probability that one or more will fail at least one of the 
acceptance criteria when all parameters are analyzed.
    8.2.6  When one or more of the parameters tested fail at least one 
of the acceptance criteria, the analyst must proceed according to 
Section 8.2.6.1 or 8.2.6.2.
    8.2.6.1  Locate and correct the source of the problem and repeat the 
test for all parameters of interest beginning with Section 8.2.3.
    8.2.6.2  Beginning with Section 8.2.3, repeat the test only for 
those parameters that failed to meet criteria. Repeated failure, 
however, will confirm a general problem with the measurement system. If 
this occurs, locate and correct the source of the problem and repeat the 
test for all compounds of interest beginning with Section 8.2.3.
    8.3  The laboratory must, on an ongoing basis, spike at least 10% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing one to ten samples per month, at least one 
spiked sample per month is required.
    8.3.1  The concentration of the spike in the sample should be 
determined as follows:
    8.3.1.1  If, as in compliance monitoring, the concentration of a 
specific parameter in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of a specific parameter in the sample 
is not being checked against a limit specific to that parameter, the 
spike should be at 20 g/L or 1 to 5 times higher than the 
background concentration determined in Section 8.3.2, whichever 
concentration would be larger.
    8.3.2  Analyze one 5-mL sample aliquot to determine the background 
concentration (B) of each parameter. If necessary, prepare a new QC 
check sample concentrate (Section 8.2.1) appropriate for the background 
concentrations in the sample. Spike a second 5-mL sample aliquot with 10 
L of the QC check sample concentrate and analyze it to 
determine the concentration after spiking (A) of each parameter. 
Calculate each percent recovery (P) as 100(A-B)%/T, where T is the known 
true value of the spike.
    8.3.3  Compare the percent recovery (P) for each parameter with the 
corresponding QC acceptance criteria found in Table 2. These acceptance 
criteria were calculated to include an allowance for error in 
measurement of both the background and spike concentrations, assuming a 
spike to background ratio of 5:1. This error will be accounted for to 
the extent that the analyst's spike to background ratio approaches 
5:1.7 If spiking was performed at a concentration lower than 20 
g/L, the analyst must use either the QC acceptance criteria in 
Table 2, or optional QC acceptance criteria calculated for the specific 
spike concentration. To calculate optional acceptance criteria for the 
recovery of a parameter: (1) Calculate accuracy (X') using the equation 
in Table 3, substituting

[[Page 35]]

the spike concentration (T) for C; (2) calculate overall precision (S') 
using the equation in Table 3, substituting X' for X; (3) calculate the 
range for recovery at the spike concentration as (100 X'/
T)2.44(100 S'/T)%.7
    8.3.4  If any individual P falls outside the designated range for 
recovery, that parameter has failed the acceptance criteria. A check 
standard containing each parameter that failed the criteria must be 
analyzed as described in Section 8.4.
    8.4  If any parameter fails the acceptance criteria for recovery in 
Section 8.3, a QC check standard containing each parameter that failed 
must be prepared and analyzed.

    Note: The frequency for the required analysis of a QC check standard 
will depend upon the number of parameters being simultaneously tested, 
the complexity of the sample matrix, and the performance of the 
laboratory. If the entire list of parameters in Table 2 must be measured 
in the sample in Section 8.3, the probability that the analysis of a QC 
check standard will be required is high. In this case the QC check 
standard should be routinely analyzed with the spiked sample.
    8.4.1  Prepare the QC check standard by adding 10 L of QC 
check sample concentrate (Section 8.2.1 or 8.3.2) to 5 mL of reagent 
water. The QC check standard needs only to contain the parameters that 
failed criteria in the test in Section 8.3.
    8.4.2  Analyze the QC check standard to determine the concentration 
measured (A) of each parameter. Calculate each percent recovery 
(Ps) as 100 (A/T)%, where T is the true value of the standard 
concentration.
    8.4.3  Compare the percent recovery (Ps) for each parameter 
with the corresponding QC acceptance criteria found in Table 2. Only 
parameters that failed the test in Section 8.3 need to be compared with 
these criteria. If the recovery of any such parameter falls outside the 
designated range, the laboratory performance for that parameter is 
judged to be out of control, and the problem must be immediately 
identified and corrected. The analytical result for that parameter in 
the unspiked sample is suspect and may not be reported for regulatory 
compliance purposes.
    8.5  As part of the QC program for the laboratory, method accuracy 
for wastewater samples must be assessed and records must be maintained. 
After the analysis of five spiked wastewater samples as in Section 8.3, 
calculate the average percent recovery (P) and the standard deviation of 
the percent recovery (sp). Express the accuracy assessment as a 
percent recovery interval from P-2sp to P+2sp. If p=90% and 
sp=10%, for example, the accuracy interval is expressed as 70-110%. 
Update the accuracy assessment for each parameter on a regular basis 
(e.g. after each five to ten new accuracy measurements).
    8.6  It is recommended that the laboratory adopt additional quality 
assurance practices for use with this method. The specific practices 
that are most productive depend upon the needs of the laboratory and the 
nature of the samples. Field duplicates may be analyzed to assess the 
precision of the environmental measurements. When doubt exists over the 
identification of a peak on the chromatogram, confirmatory techniques 
such as gas chromatography with a dissimilar column, specific element 
detector, or mass spectrometer must be used. Whenever possible, the 
laboratory should analyze standard reference materials and participate 
in relevant performance evaluation studies.
    8.7  The analyst should monitor both the performance of the 
analytical system and the effectiveness of the method in dealing with 
each sample matrix by spiking each sample, standard, and reagent water 
blank with surrogate halocarbons. A combination of bromochloromethane, 
2-bromo-1-chloropropane, and 1,4-dichlorobutane is recommended to 
encompass the range of the temperature program used in this method. From 
stock standard solutions prepared as in Section 6.5, add a volume to 
give 750 g of each surrogate to 45 mL of reagent water 
contained in a 50-mL volumetric flask, mix and dilute to volume for a 
concentration of 15 ng/L. Add 10 L of this surrogate 
spiking solution directly into the 5-mL syringe with every sample and 
reference standard analyzed. Prepare a fresh surrogate spiking solution 
on a weekly basis. If the internal standard calibration procedure is 
being used, the surrogate compounds may be added directly to the 
internal standard spiking solution (Section 7.4.2).

            9. Sample Collection, Preservation, and Handling

    9.1  All samples must be iced or refrigerated from the time of 
collection until analysis. If the sample contains free or combined 
chlorine, add sodium thiosulfate preservative (10 mg/40 mL is sufficient 
for up to 5 ppm Cl2) to the empty sample bottle just prior to 
shipping to the sampling site. EPA Methods 330.4 and 330.5 may be used 
for measurement of residual chlorine.8 Field test kits are 
available for this purpose.
    9.2  Grab samples must be collected in glass containers having a 
total volume of at least 25 mL. Fill the sample bottle just to 
overflowing in such a manner that no air bubbles pass through the sample 
as the bottle is being filled. Seal the bottle so that no air bubbles 
are entrapped in it. If preservative has been added, shake vigorously 
for 1 min. Maintain the hermetic seal on the sample bottle until time of 
analysis.
    9.3  All samples must be analyzed within 14 days of 
collection.3

[[Page 36]]

                              10. Procedure

    10.1  Table 1 summarizes the recommended operating conditions for 
the gas chromatograph. Included in this table are estimated retention 
times and MDL that can be achieved under these conditions. An example of 
the separations achieved by Column 1 is shown in Figure 5. Other packed 
columns, chromatographic conditions, or detectors may be used if the 
requirements of Section 8.2 are met.
    10.2  Calibrate the system daily as described in Section 7.
    10.3  Adjust the purge gas (nitrogen or helium) flow rate to 40 mL/
min. Attach the trap inlet to the purging device, and set the purge and 
trap system to purge (Figure 3). Open the syringe valve located on the 
purging device sample introduction needle.
    10.4  Allow the sample to come to ambient temperature prior to 
introducing it to the syringe. Remove the plunger from a 5-mL syringe 
and attach a closed syringe valve. Open the sample bottle (or standard) 
and carefully pour the sample into the syringe barrel to just short of 
overflowing. Replace the syringe plunger and compress the sample. Open 
the syringe valve and vent any residual air while adjusting the sample 
volume to 5.0 mL. Since this process of taking an aliquot destroys the 
validity of the sample for future analysis, the analyst should fill a 
second syringe at this time to protect against possible loss of data. 
Add 10.0 L of the surrogate spiking solution (Section 8.7) and 
10.0 L of the internal standard spiking solution (Section 
7.4.2), if applicable, through the valve bore, then close the valve.
    10.5  Attach the syringe-syringe valve assembly to the syringe valve 
on the purging device. Open the syringe valves and inject the sample 
into the purging chamber.
    10.6  Close both valves and purge the sample for 11.00.1 
min at ambient temperature.
    10.7  After the 11-min purge time, attach the trap to the 
chromatograph, adjust the purge and trap system to the desorb mode 
(Figure 4), and begin to temperature program the gas chromatograph. 
Introduce the trapped materials to the GC column by rapidly heating the 
trap to 180  deg.C while backflushing the trap with an inert gas between 
20 and 60 mL/min for 4 min. If rapid heating of the trap cannot be 
achieved, the GC column must be used as a secondary trap by cooling it 
to 30  deg.C (subambient temperature, if poor peak geometry or random 
retention time problems persist) instead of the initial program 
temperature of 45  deg.C
    10.8  While the trap is being desorbed into the gas chromatograph, 
empty the purging chamber using the sample introduction syringe. Wash 
the chamber with two 5-mL flushes of reagent water.
    10.9  After desorbing the sample for 4 min, recondition the trap by 
returning the purge and trap system to the purge mode. Wait 15 s then 
close the syringe valve on the purging device to begin gas flow through 
the trap. The trap temperature should be maintained at 180  deg.C After 
approximately 7 min, turn off the trap heater and open the syringe valve 
to stop the gas flow through the trap. When the trap is cool, the next 
sample can be analyzed.
    10.10  Identify the parameters in the sample by comparing the 
retention times of the peaks in the sample chromatogram with those of 
the peaks in standard chromatograms. The width of the retention time 
window used to make identifications should be based upon measurements of 
actual retention time variations of standards over the course of a day. 
Three times the standard deviation of a retention time for a compound 
can be used to calculate a suggested window size; however, the 
experience of the analyst should weigh heavily in the interpretation of 
chromatograms.
    10.11  If the response for a peak exceeds the working range of the 
system, prepare a dilution of the sample with reagent water from the 
aliquot in the second syringe and reanalyze.

                            11. Calculations

    11.1  Determine the concentration of individual compounds in the 
sample.
    11.1.1  If the external standard calibration procedure is used, 
calculate the concentration of the parameter being measured from the 
peak response using the calibration curve or calibration factor 
determined in Section 7.3.2.
    11.1.2  If the internal standard calibration procedure is used, 
calculate the concentration in the sample using the response factor (RF) 
determined in Section 7.4.3 and Equation 2.
    Equation 2

                                                                                                                
                                                                          (As)(Cis)                             
                                          Concentration (g/  = -------------                           
                                                      L)                  (Ais)(RF)                             
                                                                                                                

where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Cis=Concentration of the internal standard.

    11.2  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

                         12. Method Performance

    12.1 The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the value is above zero. \1\ The MDL concentration 
listed in

[[Page 37]]

Table 1 were obtained using reagent water.11. Similar results were 
achieved using representative wastewaters. The MDL actually achieved in 
a given analysis will vary depending on instrument sensitivity and 
matrix effects.

    12.2  This method is recommended for use in the concentration range 
from the MDL to 1000 x MDL. Direct aqueous injection techniques should 
be used to measure concentration levels above 1000 x MDL.
    12.3  This method was tested by 20 laboratories using reagent water, 
drinking water, surface water, and three industrial wastewaters spiked 
at six concentrations over the range 8.0 to 500 g/L.9 
Single operator precision, overall precision, and method accuracy were 
found to be directly related to the concentration of the parameter and 
essentially independent of the sample matrix. Linear equations to 
describe these relationships are presented in Table 3.

                               References

    1. 40 CFR part 136, appendix B.
    2. Bellar, T.A., and Lichtenberg, J.J. ``Determining Volatile 
Organics at Microgram-per-Litre-Levels by Gas Chromatography,'' Journal 
of the American Water Works Association, 66, 739 (1974).
    3. Bellar, T.A., and Lichtenberg, J.J. ``Semi-Automated Headspace 
Analysis of Drinking Waters and Industrial Waters for Purgeable Volatile 
Organic Compounds,'' Proceedings from Symposium on Measurement of 
Organic Pollutants in Water and Wastewater, American Society for Testing 
and Materials, STP 686, C.E. Van Hall, editor, 1978.
    4. ``Carcinogens--Working With Carcinogens,'' Department of Health, 
Education, and Welfare, Public Health Service, Center for Disease 
Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    5. ``OSHA Safety and Health Standards, General Industry'' (29 CFR 
part 1910), Occupational Safety and Health Administration, OSHA 2206 
(Revised, January 1976).
    6. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent 
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44 
used in the equation in Section 8.3.3 is two times the value 1.22 
derived in this report.)
    8. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for 
Chemical Analysis of Water and Wastes, EPA 600/4-79-020, U.S. 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory, Cincinnati, Ohio 45268, March 1979.
    9. ``EPA Method Study 24, Method 601--Purgeable Halocarbons by the 
Purge and Trap Method,'' EPA 600/4-84-064, National Technical 
Information Service, PB84-212448, Springfield, Virginia 22161, July 
1984.
    10. ``Method Validation Data for EPA Method 601,'' Memorandum from 
B. Potter, U.S. Environmental Protection Agency, Environmental 
Monitoring and Support Laboratory, Cincinnati, Ohio 45268, November 10, 
1983.
    11. Bellar, T. A., Unpublished data, U.S. Environmental Protection 
Agency, Environmental Monitoring and Support Laboratory, Cincinnati, 
Ohio 45268, 1981.

                         Table 1--Chromatographic Conditions and Method Detection Limits                        
----------------------------------------------------------------------------------------------------------------
                                                                   Retention time (min)         Method detection
                         Parameter                         ------------------------------------  limit (g/L)     
----------------------------------------------------------------------------------------------------------------
Chloromethane.............................................         1.50              5.28              0.08     
Bromomethane..............................................         2.17              7.05              1.18     
Dichlorodifluoromethane...................................         2.62             nd                 1.81     
Vinyl chloride............................................         2.67              5.28              0.18     
Chloroethane..............................................         3.33              8.68              0.52     
Methylene chloride........................................         5.25             10.1               0.25     
Trichlorofluoromethane....................................         7.18             nd                nd        
1,1-Dichloroethene........................................         7.93              7.72              0.13     
1,1-Dichloroethane........................................         9.30             12.6               0.07     
trans-1,2-Dichloroethene..................................        10.1               9.38              0.10     
Chloroform................................................        10.7              12.1               0.05     
1,2-Dichloroethane........................................        11.4              15.4               0.03     
1,1,1-Trichloroethane.....................................        12.6              13.1               0.03     
Carbon tetrachloride......................................        13.0              14.4               0.12     
Bromodichloromethane......................................        13.7              14.6               0.10     
1,2-Dichloropropane.......................................        14.9              16.6               0.04     
cis-1,3-Dichloropropene...................................        15.2              16.6               0.34     
Trichloroethene...........................................        15.8              13.1               0.12     
Dibromochloromethane......................................        16.5              16.6               0.09     
1,1,2-Trichloroethane.....................................        16.5              18.1               0.02     
trans-1,3-Dichloropropene.................................        16.5              18.0               0.20     
2-Chloroethylvinyl ether..................................        18.0              nd                 0.13     

[[Page 38]]

                                                                                                                
Bromoform.................................................        19.2              19.2               0.20     
1,1,2,2-Tetrachloroethane.................................        21.6              nd                 0.03     
Tetrachloroethene.........................................        21.7              15.0               0.03     
Chlorobenzene.............................................        24.2              18.8               0.25     
1,3-Dichlorobenzene.......................................        34.0              22.4               0.32     
1,2-Dichlorobenzene.......................................        34.9              23.5               0.15     
1,4-Dichlorobenzene.......................................        35.4              22.3               0.24     
----------------------------------------------------------------------------------------------------------------
Column 1 conditions: Carbopack B (60/80 mesh) coated with 1% SP-1000 packed in an 8 ft x 0.1 in. ID stainless   
  steel or glass column with helium carrier gas at 40 mL/min flow rate. Column temperature held at 45 C for 3   
  min then programmed at 8 C/min to 220 C and held for 15 min.                                                  
Column 2 conditions: Porisil-C (100/120 mesh) coated with n-octane packed in a 6 ft x 0.1 in. ID stainless steel
  or glass column with helium carrier gas at 40 mL/min flow rate. Column temperature held at 50 C for 3 min then
  programmed at 6 C/min to 170 C and held for 4 min.                                                            
nd=not determined.                                                                                              


                          Table 2--Calibration and QC Acceptance Criteria--Method 601 a                         
----------------------------------------------------------------------------------------------------------------
                                                                         Limit for s                            
                       Parameter                          Range for Q   (g/    Range for X    Range P, 
                                                        (g/L)       L)       (g/L)    Ps!(%)  
----------------------------------------------------------------------------------------------------------------
Bromodichloromethane..................................       15.2-24.8          4.3        10.7-32.0      42-172
Bromoform.............................................       14.7-25.3          4.7         5.0-29.3      13-159
Bromomethane..........................................       11.7-28.3          7.6         3.4-24.5       D-144
Carbon tetrachloride..................................       13.7-26.3          5.6        11.8-25.3      43-143
Chlorobenzene.........................................       14.4-25.6          5.0        10.2-27.4      38-150
Chloroethane..........................................       15.4-24.6          4.4        11.3-25.2      46-137
2-Chloroethylvinyl ether..............................       12.0-28.0          8.3         4.5-35.5      14-186
Chloroform............................................       15.0-25.0          4.5        12.4-24.0      49-133
Chloromethane.........................................       11.9-28.1          7.4           D-34.9       D-193
Dibromochloromethane..................................       13.1-26.9          6.3         7.9-35.1      24-191
1,2-Dichlorobenzene...................................       14.0-26.0          5.5         1.7-38.9       D-208
1,3-Dichlorobenzene...................................        9.9-30.1          9.1         6.2-32.6       7-187
1,4-Dichlorobenzene...................................       13.9-26.1          5.5        11.5-25.5      42-143
1,1-Dichloroethane....................................       16.8-23.2          3.2        11.2-24.6      47-132
1,2-Dichloroethane....................................       14.3-25.7          5.2        13.0-26.5      51-147
1,1-Dichloroethene....................................       12.6-27.4          6.6        10.2-27.3      28-167
trans-1,2-Dichloroethene..............................       12.8-27.2          6.4        11.4-27.1      38-155
1,2-Dichloropropane...................................       14.8-25.2          5.2        10.1-29.9      44-156
cis-1,3-Dichloropropene...............................       12.8-27.2          7.3         6.2-33.8      22-178
trans-1,3-Dichloropropene.............................       12.8-27.2          7.3         6.2-33.8      22-178
Methylene chloride....................................       15.5-24.5          4.0         7.0-27.6      25-162
1,1,2,2-Tetrachloroethane.............................        9.8-30.2          9.2         6.6-31.8       8-184
Tetrachloroethene.....................................       14.0-26.0          5.4         8.1-29.6      26-162
1,1,1-Trichloroethane.................................       14.2-25.8          4.9        10.8-24.8      41-138
1,1,2-Trichloroethane.................................       15.7-24.3          3.9         9.6-25.4      39-136
Trichloroethene.......................................       15.4-24.6          4.2         9.2-26.6      35-146
Trichlorofluoromethane................................       13.3-26.7          6.0         7.4-28.1      21-156
Vinyl chloride........................................       13.7-26.3          5.7         8.2-29.9      28-163
----------------------------------------------------------------------------------------------------------------
a Criteria were calculated assuming a QC check sample concentration of 20 g/L.                         
Q=Concentration measured in QC check sample, in g/L (Section 7.5.3).                                   
s=Standard deviation of four recovery measurements, in g/L (Section 8.2.4).                            
X=Average recovery for four recovery measurements, in g/L (Section 8.2.4).                             
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).                                                 
D=Detected; result must be greater than zero.                                                                   

    Note: These criteria are based directly upon the method performance 
data in Table 3. Where necessary, the limits for recovery have been 
broadened to assure applicability of the limits to concentrations below 
those used to develop Table 3.

                Table 3.--Method Accuracy and Precision as Functions of Concentration--Method 601               
----------------------------------------------------------------------------------------------------------------
                                                                     Single analyst                             
              Parameter                Accuracy, as recovery,   precision, sr' (g/L)              m>g/L)               (g/L)    
----------------------------------------------------------------------------------------------------------------
Bromodichloromethane................  1.12C-1.02                0.11X+0.04               0.20X+1.00             
Bromoform...........................  0.96C-2.05                0.12X+0.58               0.21X+2.41             
Bromomethane........................  0.76C-1.27                0.28X+0.27               0.36X+0.94             
Carbon tetrachloride................  0.98C-1.04                0.15X+0.38               0.20X+0.39             
Chlorobenzene.......................  1.00C-1.23                0.15X-0.02               0.18X+1.21             
Choroethane.........................  0.99C-1.53                0.14X-0.13               0.17X+0.63             

[[Page 39]]

                                                                                                                
2-Chloroethylvinyl ether a .........  1.00C                     0.20X                    0.35X                  
Chloroform..........................  0.93C-0.39                0.13X+0.15               0.19X-0.02             
Chloromethane.......................  0.77C+0.18                0.28X-0.31               0.52X+1.31             
Dibromochloromethane................  0.94C+2.72                0.11X+1.10               0.24X+1.68             
1,2-Dichlorobenzene.................  0.93C+1.70                0.20X+0.97               0.13X+6.13             
1,3-Dichlorobenzene.................  0.95C+0.43                0.14X+2.33               0.26X+2.34             
1,4-Dichlorobenzene.................  0.93C-0.09                0.15X+0.29               0.20X+0.41             
1,1-Dichloroethane..................  0.95C-1.08                0.09X+0.17               0.14X+0.94             
1,2-Dichloroethane..................  1.04C-1.06                0.11X+0.70               0.15X+0.94             
1,1-Dichloroethene..................  0.98C-0.87                0.21X-0.23               0.29X-0.40             
trans-1,2-Dichloroethene............  0.97C-0.16                0.11X+1.46               0.17X+1.46             
1,2-Dichloropropane a ..............  1.00C                     0.13X                    0.23X                  
cis-1,3-Dichloropropene a ..........  1.00C                     0.18X                    0.32X                  
trans-1,3-Dichloropropene a ........  1.00C                     0.18X                    0.32X                  
Methylene chloride..................  0.91C-0.93                0.11X+0.33               0.21X+1.43             
1,1,2,2-Tetrachloroethene...........  0.95C+0.19                0.14X+2.41               0.23X+2.79             
Tetrachloroethene...................  0.94C+0.06                0.14X+0.38               0.18X+2.21             
1,1,1-Trichloroethane...............  0.90C-0.16                0.15X+0.04               0.20X+0.37             
1,1,2-Trichloroethane...............  0.86C+0.30                0.13X-0.14               0.19X+0.67             
Trichloroethene.....................  0.87C+0.48                0.13X-0.03               0.23X+0.30             
Trichlorofluoromethane..............  0.89C-0.07                0.15X+0.67               0.26X+0.91             
Vinyl chloride......................  0.97C-0.36                0.13X+0.65               0.27X+0.40             
----------------------------------------------------------------------------------------------------------------
X'=Expected recovery for one or more measurements of a sample containing a concentration of C, in g/L. 
sn'=Expected single analyst standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
S\1\=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in     
  g/L.                                                                                                 
C=True value for the concentration, in g/L.                                                            
X=Average recovery found for measurements of samples containing a concentration of C, in g/L.          
a Estimates based upon the performance in a single laboratory.\10\                                              


[[Page 40]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.000


[[Page 41]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.001


[[Page 42]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.002


[[Page 43]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.003


[[Page 44]]

                     Method 602--Purgeable Aromatics

                        1. Scope and Application

    1.1  This method covers the determination of various purgeable 
aromatics. The following parameters may be determined by this method:

------------------------------------------------------------------------
                                                    STORET              
                    Parameter                         No.      CAS No.  
------------------------------------------------------------------------
Benzene..........................................     34030      71-43-2
Chlorobenzene....................................     34301     108-90-7
1,2-Dichlorobenzene..............................     34536      95-50-1
1,3-Dichlorobenzene..............................     34566     541-73-1
1,4-Dichlorobenzene..............................     34571     106-46-7
Ethylbenzene.....................................     34371     100-41-4
Toluene..........................................     34010     108-88-3
------------------------------------------------------------------------

    1.2  This is a purge and trap gas chromatographic (GC) method 
applicable to the determination of the compounds listed above in 
municipal and industrial discharges as provided under 40 CFR 136.1. When 
this method is used to analyze unfamiliar samples for any or all of the 
compounds above, compound identifications should be supported by at 
least one additional qualitative technique. This method describes 
analytical conditions for a second gas chromatographic column that can 
be used to confirm measurements made with the primary column. Method 624 
provides gas chromatograph/mass spectrometer (GC/MS) conditions 
appropriate for the qualitative and quantitative confirmation of results 
for all of the parameters listed above.
    1.3  The method detection limit (MDL, defined in Section 12.1) 
1 for each parameter is listed in Table 1. The MDL for a specific 
wastewater may differ from those listed, depending upon the nature of 
interferences in the sample matrix.
    1.4  Any modification of this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5.
    1.5  This method is restricted to use by or under the supervision of 
analysts experienced in the operation of a purge and trap system and a 
gas chromatograph and in the interpretation of gas chromatograms. Each 
analyst must demonstrate the ability to generate acceptable results with 
this method using the procedure described in Section 8.2.

                          2. Summary of Method

    2.1  An inert gas is bubbled through a 5-mL water sample contained 
in a specially-designed purging chamber at ambient temperature. The 
aromatics are efficiently transferred from the aqueous phase to the 
vapor phase. The vapor is swept through a sorbent trap where the 
aromatics are trapped. After purging is completed, the trap is heated 
and backflushed with the inert gas to desorb the aromatics onto a gas 
chromatographic column. The gas chromatograph is temperature programmed 
to separate the aromatics which are then detected with a photoionization 
detector.2, 3
    2.2  The method provides an optional gas chromatographic column that 
may be helpful in resolving the compounds of interest from interferences 
that may occur.

                            3. Interferences

    3.1  Impurities in the purge gas and organic compounds outgassing 
from the plumbing ahead of the trap account for the majority of 
contamination problems. The analytical system must be demonstrated to be 
free from contamination under the conditions of the analysis by running 
laboratory reagent blanks as described in Section 8.1.3. The use of non-
Teflon plastic tubing, non-Teflon thread sealants, or flow controllers 
with rubber components in the purge and trap system should be avoided.
    3.2  Samples can be contaminated by diffusion of volatile organics 
through the septum seal into the sample during shipment and storage. A 
field reagent blank prepared from reagent water and carried through the 
sampling and handling protocol can serve as a check on such 
contamination.
    3.3  Contamination by carry-over can occur whenever high level and 
low level samples are sequentially analyzed. To reduce carry-over, the 
purging device and sample syringe must be rinsed with reagent water 
between sample analyses. Whenever an unusually concentrated sample is 
encountered, it should be followed by an analysis of reagent water to 
check for cross contamination. For samples containing large amounts of 
water-soluble materials, suspended solids, high boiling compounds or 
high aromatic levels, it may be necessary to wash the purging device 
with a detergent solution, rinse it with distilled water, and then dry 
it in an oven at 105  deg.C between analyses. The trap and other parts 
of the system are also subject to contamination; therefore, frequent 
bakeout and purging of the entire system may be required.

                                4. Safety

    4.1  The toxicity or carcinogenicity of each reagent used in this 
method has not been precisely defined; however, each chemical compound 
should be treated as a potential health hazard. From this viewpoint, 
exposure to these chemicals must be reduced to the lowest possible level 
by whatever means available. The laboratory is responsible for 
maintaining a current awareness file of OSHA regulations regarding the 
safe handling of the chemicals specified in this method. A reference 
file of material data handling sheets should also be made available to 
all personnel involved in the chemical analysis. Additional references 
to laboratory safety

[[Page 45]]

are available and have been identified 4-6 for the information of 
the analyst.
    4.2  The following parameters covered by this method have been 
tentatively classified as known or suspected, human or mammalian 
carcinogens: benzene and 1,4-dichlorobenzene. Primary standards of these 
toxic compounds should be prepared in a hood. A NIOSH/MESA approved 
toxic gas respirator should be worn when the analyst handles high 
concentrations of these toxic compounds.

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete sampling.
    5.1.1  Vial]25-mL capacity or larger, equipped with a screw cap with 
a hole in the center (Pierce 13075 or equivalent). Detergent wash, 
rinse with tap and distilled water, and dry at 105  deg.C before use.
    5.1.2  Septum--Teflon-faced silicone (Pierce 12722 or equivalent). 
Detergent wash, rinse with tap and distilled water, and dry at 105 deg.C 
for 1 h before use.
    5.2  Purge and trap system--The purge and trap system consists of 
three separate pieces of equipment: A purging device, trap, and 
desorber. Several complete systems are now commercially available.
    5.2.1  The purging device must be designed to accept 5-mL samples 
with a water column at least 3 cm deep. The gaseous head space between 
the water column and the trap must have a total volume of less than 15 
mL. The purge gas must pass through the water column as finely divided 
bubbles with a diameter of less than 3 mm at the origin. The purge gas 
must be introduced no more than 5 mm from the base of the water column. 
The purging device illustrated in Figure 1 meets these design criteria.
    5.2.2  The trap must be at least 25 cm long and have an inside 
diameter of at least 0.105 in.
    5.2.2.1  The trap is packed with 1 cm of methyl silicone coated 
packing (Section 6.4.2) and 23 cm of 2,6-diphenylene oxide polymer 
(Section 6.4.1) as shown in Figure 2. This trap was used to develop the 
method performance statements in Section 12.
    5.2.2.2  Alternatively, either of the two traps described in Method 
601 may be used, although water vapor will preclude the measurement of 
low concentrations of benzene.
    5.2.3  The desorber must be capable of rapidly heating the trap to 
180  deg.C. The polymer section of the trap should not be heated higher 
than 180  deg.C and the remaining sections should not exceed 200  deg.C. 
The desorber illustrated in Figure 2 meets these design criteria.
    5.2.4  The purge and trap system may be assembled as a separate unit 
or be coupled to a gas chromatograph as illustrated in Figures 3, 4, and 
5.
    5.3  Gas chromatograph--An analytical system complete with a 
temperature programmable gas chromatograph suitable for on-column 
injection and all required accessories including syringes, analytical 
columns, gases, detector, and strip-chart recorder. A data system is 
recommended for measuring peak areas.
    5.3.1  Column 1--6 ft long x 0.082 in. ID stainless steel or glass, 
packed with 5% SP-1200 and 1.75% Bentone-34 on Supelcoport (100/120 
mesh) or equivalent. This column was used to develop the method 
performance statements in Section 12. Guidelines for the use of 
alternate column packings are provided in Section 10.1.
    5.3.2  Column 2--8 ft long x 0.1 in ID stainless steel or glass, 
packed with 5% 1,2,3-Tris(2-cyanoethoxy)propane on Chromosorb W-AW (60/
80 mesh) or equivalent.
    5.3.3  Detector--Photoionization detector (h-Nu Systems, Inc. Model 
PI-51-02 or equivalent). This type of detector has been proven effective 
in the analysis of wastewaters for the parameters listed in the scope 
(Section 1.1), and was used to develop the method performance statements 
in Section 12. Guidelines for the use of alternate detectors are 
provided in Section 10.1.
    5.4  Syringes--5-mL glass hypodermic with Luerlok tip (two each), if 
applicable to the purging device.
    5.5  Micro syringes--25-L, 0.006 in. ID needle.
    5.6  Syringe valve--2-way, with Luer ends (three each).
    5.7  Bottle--15-mL, screw-cap, with Teflon cap liner.
    5.8  Balance--Analytical, capable of accurately weighing 0.0001 g.

                               6. Reagents

    6.1  Reagent water--Reagent water is defined as a water in which an 
interferent is not observed at the MDL of the parameters of interest.
    6.1.1  Reagent water can be generated by passing tap water through a 
carbon filter bed containing about 1 lb of activated carbon (Filtrasorb-
300, Calgon Corp., or equivalent).
    6.1.2  A water purification system (Millipore Super-Q or equivalent) 
may be used to generate reagent water.
    6.1.3  Reagent water may also be prepared by boiling water for 15 
min. Subsequently, while maintaining the temperature at 90  deg.C, 
bubble a contaminant-free inert gas through the water for 1 h. While 
still hot, transfer the water to a narrow mouth screw-cap bottle and 
seal with a Teflon-lined septum and cap.
    6.2  Sodium thiosulfate--(ACS) Granular.
    6.3  Hydrochloric acid (1+1)--Add 50 mL of concentrated HCl (ACS) to 
50 mL of reagent water.
    6.4  Trap Materials:

[[Page 46]]

    6.4.1  2,6-Diphenylene oxide polymer--Tenax, (60/80 mesh), 
chromatographic grade or equivalent.
    6.4.2  Methyl silicone packing--3% OV-1 on Chromosorb-W (60/80 mesh) 
or equivalent.
    6.5  Methanol--Pesticide quality or equivalent.
    6.6  Stock standard solutions--Stock standard solutions may be 
prepared from pure standard materials or purchased as certified 
solutions. Prepare stock standard solutions in methanol using assayed 
liquids. Because of the toxicity of benzene and 1,4-dichlorobenzene, 
primary dilutions of these materials should be prepared in a hood. A 
NIOSH/MESA approved toxic gas respirator should be used when the analyst 
handles high concentrations of such materials.
    6.6.1  Place about 9.8 mL of methanol into a 10-mL ground glass 
stoppered volumetric flask. Allow the flask to stand, unstoppered, for 
about 10 min or until all alcohol wetted surfaces have dried. Weigh the 
flask to the nearest 0.1 mg.
    6.6.2  Using a 100-L syringe, immediately add two or more 
drops of assayed reference material to the flask, then reweigh. Be sure 
that the drops fall directly into the alcohol without contacting the 
neck of the flask.
    6.6.3  Reweigh, dilute to volume, stopper, then mix by inverting the 
flask several times. Calculate the concentration in g/
L from the net gain in weight. When compound purity is assayed 
to be 96% or greater, the weight can be used without correction to 
calculate the concentration of the stock standard. Commercially prepared 
stock standards can be used at any concentration if they are certified 
by the manufacturer or by an independent source.
    6.6.4  Transfer the stock standard solution into a Teflon-sealed 
screw-cap bottle. Store at 4  deg.C and protect from light.
    6.6.5  All standards must be replaced after one month, or sooner if 
comparison with check standards indicates a problem.
    6.7  Secondary dilution standards--Using stock standard solutions, 
prepare secondary dilution standards in methanol that contain the 
compounds of interest, either singly or mixed together. The secondary 
dilution standards should be prepared at concentrations such that the 
aqueous calibration standards prepared in Section 7.3.1 or 7.4.1 will 
bracket the working range of the analytical system. Secondary solution 
standards must be stored with zero headspace and should be checked 
frequently for signs of degradation or evaporation, especially just 
prior to preparing calibration standards from them.
    6.8  Quality control check sample concentrate--See Section 8.2.1.

                             7.  Calibration

    7.1  Assemble a purge and trap system that meets the specifications 
in Section 5.2. Condition the trap overnight at 180  deg.C by 
backflushing with an inert gas flow of at least 20 mL/min. Condition the 
trap for 10 min once daily prior to use.
    7.2  Connect the purge and trap system to a gas chromatograph. The 
gas chromatograph must be operated using temperature and flow rate 
conditions equivalent to those given in Table 1. Calibrate the purge and 
trap-gas chromatographic system using either the external standard 
technique (Section 7.3) or the internal standard technique (Section 
7.4).
    7.3  External standard calibration procedure:
    7.3.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter by carefully adding 20.0 
L of one or more secondary dilution standards to 100, 500, or 
1000 mL of reagent water. A 25-L syringe with a 0.006 in. ID 
needle should be used for this operation. One of the external standards 
should be at a concentration near, but above, the MDL (Table 1) and the 
other concentrations should correspond to the expected range of 
concentrations found in real samples or should define the working range 
of the detector. These aqueous standards must be prepared fresh daily.
    7.3.2  Analyze each calibration standard according to Section 10, 
and tabulate peak height or area responses versus the concentration in 
the standard. The results can be used to prepare a calibration curve for 
each compound. Alternatively, if the ratio of response to concentration 
(calibration factor) is a constant over the working range (<10% relative 
standard deviation, RSD), linearity through the origin can be assumed 
and the average ratio or calibration factor can be used in place of a 
calibration curve.
    7.4  Internal standard calibration procedure--To use this approach, 
the analyst must select one or more internal standards that are similar 
in analytical behavior to the compounds of interest. The analyst must 
further demonstrate that the measurement of the internal standard is not 
affected by method or matrix interferences. Because of these 
limitations, no internal standard can be suggested that is applicable to 
all samples. The compound, ,,,-
trifluorotoluene, recommended as a surrogate spiking compound in Section 
8.7 has been used successfully as an internal standard.
    7.4.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest as described in 
Section 7.3.1.
    7.4.2  Prepare a spiking solution containing each of the internal 
standards using the procedures described in Sections 6.6 and 6.7. It is 
recommended that the secondary dilution standard be prepared at a 
concentration of 15 g/mL of each internal standard compound. 
The addition of 10 l of this

[[Page 47]]

standard to 5.0 mL of sample or calibration standard would be equivalent 
to 30 g/L.
    7.4.3  Analyze each calibration standard according to Section 10, 
adding 10 L of internal standard spiking solution directly to 
the syringe (Section 10.4). Tabulate peak height or area responses 
against concentration for each compound and internal standard, and 
calculate response factors (RF) for each compound using Equation 1.

                                                                                                                
                                                                   RF=      (As)(Cis)    (Ais)(Cs)              
                                                                                                                

                                                              Equation 1
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Cis=Concentration of the internal standard
    Cs=Concentration of the parameter to be measured.
If the RF value over the working range is a constant (<10% RSD), the RF 
can be assumed to be invariant and the average RF can be used for 
calculations. Alternatively, the results can be used to plot a 
calibration curve of response ratios, As/Ais, vs. RF.
    7.5  The working calibration curve, calibration factor, or RF must 
be verified on each working day by the measurement of a QC check sample.
    7.5.1  Prepare the QC check sample as described in Section 8.2.2.
    7.5.2  Analyze the QC check sample according to Section 10.
    7.5.3  For each parameter, compare the response (Q) with the 
corresponding calibration acceptance criteria found in Table 2. If the 
responses for all parameters of interest fall within the designated 
ranges, analysis of actual samples can begin. If any individual Q falls 
outside the range, a new calibration curve, calibration factor, or RF 
must be prepared for that parameter according to Section 7.3 or 7.4.

                           8. Quality Control

    8.1 Each laboratory that uses this method is required to operate a 
formal quality control program. The mimimum requirements of this program 
consist of an initial demonstration of laboratory capability and an 
ongoing analysis of spiked samples to evaluate and document data 
quality. The laboratory must maintain records to document the quality of 
data that is generated. Ongoing data quality checks are compared with 
established performance criteria to determine if the results of analyses 
meet the performance characteristics of the method. When results of 
sample spikes indicate atypical method performance, a quality control 
check standard must be analyzed to confirm that the measurements were 
performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occurring in 
chromatography, the analyst is permitted certain options (detailed in 
Section 10.1) to improve the separations or lower the cost of 
measurements. Each time such a modification is made to the method, the 
analyst is required to repeat the procedure in Section 8.2.
    8.1.3  Each day, the analyst must analyze a reagent water blank to 
demonstrate that interferences from the analytical system are under 
control.
    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 10% of all samples to monitor and evaluate laboratory data 
quality. This procedure is described in Section 8.3.
    8.1.5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 10% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.5.
    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality control (QC) check sample concentrate is required 
containing each parameter of interest at a concentration of 10 
g/mL in methanol. The QC check sample concentrate must be 
obtained from the U.S. Environmental Protection Agency, Environmental 
Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If 
not available from that source, the QC check sample concentrate must be 
obtained from another external source. If not available from either 
source above, the QC check sample concentrate must be prepared by the 
laboratory using stock standards prepared independently from those used 
for calibration.
    8.2.2  Prepare a QC check sample to contain 20 g/L of each 
parameter by adding 200 L of QC check sample concentrate to 100 
mL of reagant water.
    8.2.3  Analyze four 5-mL aliquots of the well-mixed QC check sample 
according to Section 10.
    8.2.4  Calculate the average recovery (X) in g/L, and the 
standard deviation of the recovery (s) in g/L, for each 
parameter of interest using the four results.
    8.2.5  For each parameter compare s and X with the corresponding 
acceptance criteria

[[Page 48]]

for precision and accuracy, respectively, found in Table 2. If s and X 
for all parameters of interest meet the acceptance criteria, the system 
performance is acceptable and analysis of actual samples can begin. If 
any individual s exceeds the precision limit or any individual X falls 
outside the range for accuracy, the system performance is unacceptable 
for that parameter.

    Note: The large number of parameters in Table 2 present a 
substantial probability that one or more will fail at least one of the 
acceptance criteria when all parameters are analyzed.

    8.2.6  When one or more of the parameters tested fail at least one 
of the acceptance criteria, the analyst must proceed according to 
Section 8.2.6.1 or 8.2.6.2.
    8.2.6.1  Locate and correct the source of the problem and repeat the 
test for all parameters of interest beginning with Section 8.2.3.
    8.2.6.2  Beginning with Section 8.2.3, repeat the test only for 
those parameters that failed to meet criteria. Repeated failure, 
however, will confirm a general problem with the measurement system. If 
this occurs, locate and correct the source of the problem and repeat the 
test for all compounds of interest beginning with Section 8.2.3.
    8.3  The laboratory must, on an ongoing basis, spike at least 10% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing one to ten samples per month, at least one 
spiked sample per month is required.
    8.3.1  The concentration of the spike in the sample should be 
determined as follows:
    8.3.1.1  If, as in compliance monitoring, the concentration of a 
specific parameter in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of a specific parameter in the sample 
is not being checked against a limit specific to that parameter, the 
spike should be at 20 g/L or 1 to 5 times higher than the 
background concentration determined in Section 8.3.2, whichever 
concentration would be larger.
    8.3.2  Analyze one 5-mL sample aliquot to determine the background 
concentration (B) of each parameter. If necessary, prepare a new QC 
check sample concentrate (Section 8.2.1) appropriate for the background 
concentrations in the sample. Spike a second 5-mL sample aliquot with 10 
L of the QC check sample concentrate and analyze it to 
determine the concentration after spiking (A) of each parameter. 
Calculate each percent recovery (P) as 100(A-B)%/T, where T is the known 
true value of the spike.
    8.3.3  Compare the percent recovery (P) for each parameter with the 
corresponding QC acceptance criteria found in Table 2. These acceptance 
criteria were calculated to include an allowance for error in 
measurement of both the background and spike concentrations, assuming a 
spike to background ratio of 5:1. This error will be accounted for to 
the extent that the analyst's spike to background ratio approaches 
5:1.7 If spiking was performed at a concentration lower than 20 
g/L, the analyst must use either the QC acceptance criteria in 
Table 2, or optional QC acceptance criteria calculated for the specific 
spike concentration. To calculate optional acceptance criteria for the 
recovery of a parameter: (1) Calculate accuracy (X') using the equation 
in Table 3, substituting the spike concentration (T) for C; (2) 
calculate overall precision (S') using the equation in Table 3, 
substituting X' for X; (3) calculate the range for recovery at the spike 
concentration as (100 X'/T) plus-minus 2.44(100 S'/T)%.7
    8.3.4  If any individual P falls outside the designated range for 
recovery, that parameter has failed the acceptance criteria. A check 
standard containing each parameter that failed the criteria must be 
analyzed as described in Section 8.4.
    8.4  If any parameter fails the acceptance criteria for recovery in 
Section 8.3, a QC check standard containing each parameter that failed 
must be prepared and analyzed.

    Note: The frequency for the required analysis of a QC check standard 
will depend upon the number of parameters being simultaneously tested, 
the complexity of the sample matrix, and the performance of the 
laboratory.
    8.4.1  Prepare the QC check standard by adding 10 L of QC 
check sample concentrate (Section 8.2.1 or 8.3.2) to 5 mL of reagent 
water. The QC check standard needs only to contain the parameters that 
failed criteria in the test in Section 8.3.
    8.4.2  Analyze the QC check standard to determine the concentration 
measured (A) of each parameter. Calculate each percent recovery 
(Ps) as 100 (A/T)%, where T is the true value of the standard 
concentration.
    8.4.3  Compare the percent recovery (Ps) for each parameter 
with the corresponding QC acceptance criteria found in Table 2. Only 
parameters that failed the test in Section 8.3 need to be compared with 
these criteria. If the recovery of any such parameter falls outside the 
designated range, the laboratory performance for that parameter is 
judged to be out of control, and the problem must be immediately 
identified and corrected. The analytical result for that parameter in 
the unspiked sample is suspect and may not be reported for regulatory 
compliance purposes.
    8.5  As part of the QC program for the laboratory, method accuracy 
for wastewater samples must be assessed and records must be maintained. 
After the analysis of five

[[Page 49]]

spiked wastewater samples as in Section 8.3, calculate the average 
percent recovery (P) and the standard deviation of the percent recovery 
(sp). Express the accuracy assessment as a percent recovery 
interval from P-2sp to P+2sp. If P=90% and sp=10%, for 
example, the accuracy interval is expressed as 70-110%. Update the 
accuracy assessment for each parameter on a regular basis (e.g. after 
each five to ten new accuracy measurements).
    8.6  It is recommended that the laboratory adopt additional quality 
assurance practices for use with this method. The specific practices 
that are most productive depend upon the needs of the laboratory and the 
nature of the samples. Field duplicates may be analyzed to assess the 
precision of the environmental measurements. When doubt exists over the 
identification of a peak on the chromatogram, confirmatory techniques 
such as gas chromatography with a dissimilar column, specific element 
detector, or mass spectrometer must be used. Whenever possible, the 
laboratory should analyze standard reference materials and participate 
in relevant performance evaluation studies.
    8.7  The analyst should monitor both the performance of the 
analytical system and the effectiveness of the method in dealing with 
each sample matrix by spiking each sample, standard, and reagent water 
blank with surrogate compounds (e.g. , , ,-
trifluorotoluene) that encompass the range of the temperature program 
used in this method. From stock standard solutions prepared as in 
Section 6.6, add a volume to give 750 g of each surrogate to 45 
mL of reagent water contained in a 50-mL volumetric flask, mix and 
dilute to volume for a concentration of 15 mg/L. Add 10 
L of this surrogate spiking solution directly into the 5-mL 
syringe with every sample and reference standard analyzed. Prepare a 
fresh surrogate spiking solution on a weekly basis. If the internal 
standard calibration procedure is being used, the surrogate compounds 
may be added directly to the internal standard spiking solution (Section 
7.4.2).

            9. Sample Collection, Preservation, and Handling

    9.1  The samples must be iced or refrigerated from the time of 
collection until analysis. If the sample contains free or combined 
chlorine, add sodium thiosulfate preservative (10 mg/40 mL is sufficient 
for up to 5 ppm Cl2) to the empty sample bottle just prior to 
shipping to the sampling site. EPA Method 330.4 or 330.5 may be used for 
measurement of residual chlorine.8 Field test kits are available 
for this purpose.
    9.2  Collect about 500 mL of sample in a clean container. Adjust the 
pH of the sample to about 2 by adding 1+1 HCl while stirring. Fill the 
sample bottle in such a manner that no air bubbles pass through the 
sample as the bottle is being filled. Seal the bottle so that no air 
bubbles are entrapped in it. Maintain the hermetic seal on the sample 
bottle until time of analysis.
    9.3  All samples must be analyzed within 14 days of 
collection.3

                              10. Procedure

    10.1  Table 1 summarizes the recommended operating conditions for 
the gas chromatograph. Included in this table are estimated retention 
times and MDL that can be achieved under these conditions. An example of 
the separations achieved by Column 1 is shown in Figure 6. Other packed 
columns, chromatographic conditions, or detectors may be used if the 
requirements of Section 8.2 are met.
    10.2  Calibrate the system daily as described in Section 7.
    10.3  Adjust the purge gas (nitrogen or helium) flow rate to 40 mL/
min. Attach the trap inlet to the purging device, and set the purge and 
trap system to purge (Figure 3). Open the syringe valve located on the 
purging device sample introduction needle.
    10.4  Allow the sample to come to ambient temperature prior to 
introducing it to the syringe. Remove the plunger from a 5-mL syringe 
and attach a closed syringe valve. Open the sample bottle (or standard) 
and carefully pour the sample into the syringe barrel to just short of 
overflowing. Replace the syringe plunger and compress the sample. Open 
the syringe valve and vent any residual air while adjusting the sample 
volume to 5.0 mL. Since this process of taking an aliquot destroys the 
validity of the sample for future analysis, the analyst should fill a 
second syringe at this time to protect against possible loss of data. 
Add 10.0 L of the surrogate spiking solution (Section 8.7) and 
10.0 L of the internal standard spiking solution (Section 
7.4.2), if applicable, through the valve bore, then close the valve.
    10.5  Attach the syringe-syringe valve assembly to the syringe valve 
on the purging device. Open the syringe valves and inject the sample 
into the purging chamber.
    10.6  Close both valves and purge the sample for 12.00.1 
min at ambient temperature.
    10.7  After the 12-min purge time, disconnect the purging device 
from the trap. Dry the trap by maintaining a flow of 40 mL/min of dry 
purge gas through it for 6 min (Figure 4). If the purging device has no 
provision for bypassing the purger for this step, a dry purger should be 
inserted into the device to minimize moisture in the gas. Attach the 
trap to the chromatograph, adjust the purge and trap system to the 
desorb mode (Figure 5), and begin to temperature program the gas 
chromatograph. Introduce the trapped materials to the GC column by 
rapidly heating the trap to 180  deg.C while backflushing the trap with 
an inert gas between 20 and 60 mL/min for 4 min. If rapid heating of the 
trap cannot be achieved, the GC column must be used as

[[Page 50]]

a secondary trap by cooling it to 30  deg.C (subambient temperature, if 
poor peak geometry and random retention time problems persist) instead 
of the initial program temperature of 50  deg.C.
    10.8  While the trap is being desorbed into the gas chromatograph 
column, empty the purging chamber using the sample introduction syringe. 
Wash the chamber with two 5-mL flushes of reagent water.
    10.9  After desorbing the sample for 4 min, recondition the trap by 
returning the purge and trap system to the purge mode. Wait 15 s, then 
close the syringe valve on the purging device to begin gas flow through 
the trap. The trap temperature should be maintained at 180  deg.C. After 
approximately 7 min, turn off the trap heater and open the syringe valve 
to stop the gas flow through the trap. When the trap is cool, the next 
sample can be analyzed.
    10.10  Identify the parameters in the sample by comparing the 
retention times of the peaks in the sample chromatogram with those of 
the peaks in standard chromatograms. The width of the retention time 
window used to make identifications should be based upon measurements of 
actual retention time variations of standards over the course of a day. 
Three times the standard deviation of a retention time for a compound 
can be used to calculate a suggested window size; however, the 
experience of the analyst should weigh heavily in the interpretation of 
chromatograms.
    10.11  If the response for a peak exceeds the working range of the 
system, prepare a dilution of the sample with reagent water from the 
aliquot in the second syringe and reanalyze.

                            11. Calculations

    11.1  Determine the concentration of individual compounds in the 
sample.
    11.1.1  If the external standard calibration procedure is used, 
calculate the concentration of the parameter being measured from the 
peak response using the calibration curve or calibration factor 
determined in Section 7.3.2.
    11.1.2  If the internal standard calibration procedure is used, 
calculate the concentration in the sample using the response factor (RF) 
determined in Section 7.4.3 and Equation 2.

                                                                                                                
                                                                          (As)(Cis)                             
                                          Concentration (g/  = -------------                           
                                                      L)                  (Ais)(RF)                             
                                                                                                                

    Equation 2
where:
    As = Response for the parameter to be measured.
    Ais = Response for the internal standard.
    Cis = Concentration of the internal standard.
    11.2  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

                         12. Method Performance

    12.1  The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the value is above zero.1 The MDL concentrations 
listed in Table 1 were obtained using reagent water.9 Similar 
results were achieved using representative wastewaters. The MDL actually 
achieved in a given analysis will vary depending on instrument 
sensitivity and matrix effects.
    12.2  This method has been demonstrated to be applicable for the 
concentration range from the MDL to 100 X MDL.9 Direct aqueous 
injection techniques should be used to measure concentration levels 
above 1000 x MDL.
    12.3  This method was tested by 20 laboratories using reagent water, 
drinking water, surface water, and three industrial wastewaters spiked 
at six concentrations over the range 2.1 to 550 g/L.9 
Single operator precision, overall precision, and method accuracy were 
found to be directly related to the concentration of the parameter and 
essentially independent of the sample matrix. Linear equations to 
describe these relationships are presented in Table 3.

                               References

    1. 40 CFR part 136, appendix B.
    2. Lichtenberg, J.J. ``Determining Volatile Organics at Microgram-
per-Litre-Levels by Gas Chromatography,'' Journal American Water Works 
Association, 66, 739 (1974).
    3. Bellar, T.A., and Lichtenberg, J.J. ``Semi-Automated Headspace 
Analysis of Drinking Waters and Industrial Waters for Purgeable Volatile 
Organic Compounds,'' Proceedings of Symposium on Measurement of Organic 
Pollutants in Water and Wastewater. American Society for Testing and 
Materials, STP 686, C.E. Van Hall, editor, 1978.
    4. ``Carcinogens--Working with Carcinogens,'' Department of Health, 
Education, and Welfare, Public Health Service, Center for Disease 
Control, National Institute for Occupational Safety and Health. 
Publication No. 77-206, August 1977.
    5. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR 
part 1910), Occupational Safety and Health Administration, OSHA 2206 
(Revised, January 1976).
    6. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Safety, 3rd Edition, 1979.
    7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent 
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44

[[Page 51]]

used in the equation in Section 8.3.3. is two times the value 1.22 
derived in this report.)
    8.``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for 
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. 
Environmental Protection Agency, Office of Research and Development, 
Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268. 
March 1979.
    9. ``EPA Method Study 25, Method 602, Purgeable Aromatics,'' EPA 
600/4-84-042, National Technical Information Service, PB84-196682, 
Springfield, Virginia 22161, May 1984.

     Table 1--Chromatographic Conditions and Method Detection Limits    
------------------------------------------------------------------------
                                      Retention time (min)     Method   
                                     ----------------------   detection 
              Parameter                                         limit   
                                       Column 1   Column 2  (g/
                                                                 L)     
------------------------------------------------------------------------
Benzene.............................       3.33       2.75         0.2  
Toluene.............................       5.75       4.25         0.2  
Ethylbenzene........................       8.25       6.25         0.2  
Chlorobenzene.......................       9.17       8.02         0.2  
1,4-Dichlorobenzene.................      16.8       16.2          0.3  
1,3-Dichlorobenzene.................      18.2       15.0          0.4  
1,2-Dichlorobenzene.................      25.9       19.4          0.4  
------------------------------------------------------------------------
Column 1 conditions: Supelcoport (100/120 mesh) coated with 5% SP-1200/ 
  1.75% Bentone-34 packed in a 6 ft x 0.085 in. ID stainless steel      
  column with helium carrier gas at 36 mL/min flow rate. Column         
  temperature held at 50 C for 2 min then programmed at 6 C/min to 90 C 
  for a final hold.                                                     
Column 2 conditions: Chromosorb W-AW (60/80 mesh) coated with 5% 1,2,3- 
  Tris(2-cyanoethyoxy)propane packed in a 6 ft x 0.085 in. ID stainless 
  steel column with helium carrier gas at 30 mL/min flow rate. Column   
  temperature held at 40 C for 2 min then programmed at 2 C/min to 100 C
  for a final hold.                                                     


                          Table 2--Calibration and QC Acceptance Criteria--Method 602 a                         
----------------------------------------------------------------------------------------------------------------
                                                                                          Range for X           
                                                              Range for Q   Limit for s  (g/  Range for
                         Parameter                           (g/  (g/       L)       P, Ps (%)
                                                                  L)            L)                              
----------------------------------------------------------------------------------------------------------------
Benzene....................................................     15.4-24.6         4.1       10.0-27.9     39-150
Chlorobenzene..............................................     16.1-23.9         3.5       12.7-25.4     55-135
1,2-Dichlorobenzene........................................     13.6-26.4         5.8       10.6-27.6     37-154
1,3-Dichlorobenzene........................................     14.5-25.5         5.0       12.8-25.5     50-141
1,4-Dichlorobenzene........................................     13.9-26.1         5.5       11.6-25.5     42-143
Ethylbenzene...............................................     12.6-27.4         6.7       10.0-28.2     32-160
Toluene....................................................     15.5-24.5         4.0       11.2-27.7     46-148
----------------------------------------------------------------------------------------------------------------
Q=Concentration measured in QC check sample, in g/L (Section 7.5.3).                                   
s=Standard deviation of four recovery measurements, in g/L (Section 8.2.4).                            
X=Average recovery for four recovery measurements, in g/L (Section 8.2.4).                             
Ps, P=Percent recovery measured (Section 8.3.2, Section 8.4.2).                                                 
a Criteria were calculated assuming a QC check sample concentration of 20 g/L.                         
                                                                                                                
 Note: These criteria are based directly upon the method performance data in Table 3. Where necessary, the      
  limits for recovery have been broadened to assure applicability of the limits to concentrations below those   
  used to develop Table 3.                                                                                      


                Table 3--Method Accuracy and Precision as Functions of Concentration--Method 602                
----------------------------------------------------------------------------------------------------------------
                                                                   Accuracy, as   Single analyst      Overall   
                            Parameter                               recovery, X    precision, s    precision, S 
                                                                  (g/L)  (g/L)  (g/L)
----------------------------------------------------------------------------------------------------------------
Benzene.........................................................      0.92C+0.57      0.09X+0.59      0.21X+0.56
Chlorobenzene...................................................      0.95C+0.02      0.09X+0.23      0.17X+0.10
1,2-Dichlorobenzene.............................................      0.93C+0.52      0.17X-0.04      0.22X+0.53
1,3-Dichlorobenzene.............................................      0.96C-0.05      0.15X-0.10      0.19X+0.09
1,4-Dichlorobenzene.............................................      0.93C-0.09      0.15X+0.28      0.20X+0.41
Ethylbenzene....................................................      0.94C+0.31      0.17X+0.46      0.26X+0.23
Toluene.........................................................      0.94C+0.65      0.09X+0.48      0.18X+0.71
----------------------------------------------------------------------------------------------------------------
X=Expected recovery for one or more measurements of a sample containing a concentration of C, in g/L.  
s=Expected single analyst standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
S=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
C=True value for the Concentration, in g/L.                                                            
X=Average recovery found for measurements of samples containing a concentration of C, in g/L.          


[[Page 52]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.004


[[Page 53]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.005


[[Page 54]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.006


[[Page 55]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.007


[[Page 56]]

                 Method 603--Acrolein and Acrylonitrile

                        1. Scope and Application

    1.1  This method covers the determination of acrolein and 
acrylonitrile. The following parameters may be determined by this 
method:

------------------------------------------------------------------------
                                                    STORET              
                    Parameter                         No.      CAS No.  
------------------------------------------------------------------------
Acrolein.........................................     34210     107-02-8
Acrylonitrile....................................     34215     107-13-1
------------------------------------------------------------------------
                                                                        

    1.2  This is a purge and trap gas chromatographic (GC) method 
applicable to the determination of the compounds listed above in 
municipal and industrial discharges as provided under 40 CFR 136.1. When 
this method is used to analyze unfamiliar samples for either or both of 
the compounds above, compound identifications should be supported by at 
least one additional qualitative technique. This method describes 
analytical conditions for a second gas chromatographic column that can 
be used to confirm measurements made with the primary column. Method 624 
provides gas chromatograph/mass spectrometer (GC/MS) conditions 
appropriate for the qualitative and quantitative confirmation of results 
for the parameters listed above, if used with the purge and trap 
conditions described in this method.
    1.3  The method detection limit (MDL, defined in Section 12.1)1 
for each parameter is listed in Table 1. The MDL for a specific 
wastewater may differ from those listed, depending upon the nature of 
interferences in the sample matrix.
    1.4  Any modification of this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5.
    1.5  This method is restricted to use by or under the supervision of 
analysts experienced in the operation of a purge and trap system and a 
gas chromatograph and in the interpretation of gas chromatograms. Each 
analyst must demonstrate the ability to generate acceptable results with 
this method using the procedure described in Section 8.2.

                          2. Summary of Method

    2.1  An inert gas is bubbled through a 5-mL water sample contained 
in a heated purging chamber. Acrolein and acrylonitrile are transferred 
from the aqueous phase to the vapor phase. The vapor is swept through a 
sorbent trap where the analytes are trapped. After the purge is 
completed, the trap is heated and backflushed with the inert gas to 
desorb the compound onto a gas chromatographic column. The gas 
chromatograph is temperature programmed to separate the analytes which 
are then detected with a flame ionization detector.2, 3
    2.2  The method provides an optional gas chromatographic column that 
may be helpful in resolving the compounds of interest from the 
interferences that may occur.

                            3. Interferences

    3.1  Impurities in the purge gas and organic compound outgassing 
from the plumbing of the trap account for the majority of contamination 
problems. The analytical system must be demonstrated to be free from 
contamination under the conditions of the analysis by running laboratory 
reagent blanks as described in Section 8.1.3. The use of non-Teflon 
plastic tubing, non-Teflon thread sealants, or flow controllers with 
rubber components in the purge and trap system should be avoided.
    3.2  Samples can be contaminated by diffusion of volatile organics 
through the septum seal into the sample during shipment and storage. A 
field reagent blank prepared from reagent water and carried through the 
sampling and handling protocol can serve as a check on such 
contamination.
    3.3  Contamination by carry-over can occur whenever high level and 
low level samples are sequentially analyzed. To reduce carry-over, the 
purging device and sample syringe must be rinsed between samples with 
reagent water. Whenever an unusually concentrated sample is encountered, 
it should be followed by an analysis of reagent water to check for cross 
contamination. For samples containing large amounts of water-soluble 
materials, suspended solids, high boiling compounds or high analyte 
levels, it may be necessary to wash the purging device with a detergent 
solution, rinse it with distilled water, and then dry it in an oven at 
105  deg.C between analyses. The trap and other parts of the system are 
also subject to contamination, therefore, frequent bakeout and purging 
of the entire system may be required.

                                4. Safety

    4.1  The toxicity or carcinogenicity of each reagent used in this 
method has not been precisely defined; however, each chemical compound 
should be treated as a potential health hazard. From this view point, 
exposure to these chemicals must be reduced to the lowest possible level 
by whatever means available. The laboratory is responsible for 
maintaining a current awareness file of OSHA regulations regarding the 
safe handling of the chemicals specified in this method. A reference 
file of material data handling sheets should also be made available to 
all personnel involved in the chemical analysis. Additional references 
to laboratory safety are available and have been identified4, 6 for 
the information of the analyst.

[[Page 57]]

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete sampling.
    5.1.1  Vial--25-mL capacity or larger, equipped with a screw cap 
with a hole in the center (Pierce 13075 or equivalent). Detergent wash, 
rinse with tap and distilled water, and dry at 105  deg.C before use.
    5.1.2  Septum--Teflon-faced silicone (Pierce 12722 or equivalent). 
Detergent wash, rinse with tap and distilled water and dry at 105  deg.C 
for 1 h before use.
    5.2  Purge and trap system--The purge and trap system consists of 
three separate pieces of equipment: a purging device, trap, and 
desorber. Several complete systems are now commercially available.
    5.2.1  The purging device must be designed to accept 5-mL, samples 
with a water column at least 3 cm deep. The gaseous head space between 
the water column and the trap must have a total volume of less than 15 
mL. The purge gas must pass through the water column as finely divided 
bubbles with a diameter of less than 3 mm at the origin. The purge gas 
must be introduced no more than 5 mm from the base of the water column. 
The purging device must be capable of being heated to 85  deg.C within 
3.0 min after transfer of the sample to the purging device and being 
held at 85 2  deg.C during the purge cycle. The entire water 
column in the purging device must be heated. Design of this modification 
to the standard purging device is optional, however, use of a water bath 
is suggested.
    5.2.1.1  Heating mantle--To be used to heat water bath.
    5.2.1.2  Temperature controller--Equipped with thermocouple/sensor 
to accurately control water bath temperature to 2  deg.C. 
The purging device illustrated in Figure 1 meets these design criteria.
    5.2.2  The trap must be at least 25 cm long and have an inside 
diameter of at least 0.105 in. The trap must be packed to contain 1.0 cm 
of methyl silicone coated packing (Section 6.5.2) and 23 cm of 2,6-
diphenylene oxide polymer (Section 6.5.1). The minimum specifications 
for the trap are illustrated in Figure 2.
    5.2.3  The desorber must be capable of rapidly heating the trap to 
180  deg.C, The desorber illustrated in Figure 2 meets these design 
criteria.
    5.2.4  The purge and trap system may be assembled as a separate unit 
as illustrated in Figure 3 or be coupled to a gas chromatograph.
    5.3  pH paper--Narrow pH range, about 3.5 to 5.5 (Fisher Scientific 
Short Range Alkacid No. 2, 14-837-2 or equivalent).
    5.4  Gas chromatograph--An analytical system complete with a 
temperature programmable gas chromatograph suitable for on-column 
injection and all required accessories including syringes, analytical 
columns, gases, detector, and strip-chart recorder. A data system is 
recommended for measuring peak areas.
    5.4.1  Column 1--10 ft long x 2 mm ID glass or stainless steel, 
packed with Porapak-QS (80/100 mesh) or equivalent. This column was used 
to develop the method performance statements in Section 12. Guidelines 
for the use of alternate column packings are provided in Section 10.1.
    5.4.2  Column 2--6 ft long x 0.1 in. ID glass or stainless steel, 
packed with Chromosorb 101 (60/80 mesh) or equivalent.
    5.4.3  Detector--Flame ionization detector. This type of detector 
has proven effective in the analysis of wastewaters for the parameters 
listed in the scope (Section 1.1), and was used to develop the method 
performance statements in Section 12. Guidelines for the use of 
alternate detectors are provided in Section 10.1.
    5.5  Syringes--5-mL, glass hypodermic with Luerlok tip (two each).
    5.6  Micro syringes--25-L, 0.006 in. ID needle.
    5.7  Syringe valve--2-way, with Luer ends (three each).
    5.8  Bottle--15-mL, screw-cap, with Teflon cap liner.
    5.9  Balance--Analytical, capable of accurately weighing 0.0001 g.

                               6. Reagents

    6.1  Reagent water--Reagent water is defined as a water in which an 
interferent is not observed at the MDL of the parameters of interest.
    6.1.1  Reagent water can be generated by passing tap water through a 
carbon filter bed containing about 1 lb of activated carbon (Filtrasorb-
300, Calgon Corp., or equivalent).
    6.1.2  A water purification system (Millipore Super-Q or equivalent) 
may be used to generate reagent water.
    6.1.3  Regent water may also be prepared by boiling water for 15 
min. Subsequently, while maintaining the temperature at 90  deg.C, 
bubble a contaminant-free inert gas through the water for 1 h. While 
still hot, transfer the water to a narrow mouth screw-cap bottle and 
seal with a Teflon-lined septum and cap.
    6.2  Sodium thiosulfate--(ACS) Granular.
    6.3  Sodium hydroxide solution (10 N)--Dissolve 40 g of NaOH (ACS) 
in reagent water and dilute to 100 mL.
    6.4  Hydrochloric acid (1+1)--Slowly, add 50 mL of concentrated HCl 
(ACS) to 50 mL of reagent water.
    6.5  Trap Materials:
    6.5.1  2,6-Diphenylene oxide polymer--Tenax (60/80 mesh), 
chromatographic grade or equivalent.
    6.5.2  Methyl silicone packing--3% OV-1 on Chromosorb-W (60/80 mesh) 
or equivalent.

[[Page 58]]

    6.6  Stock standard solutions--Stock standard solutions may be 
prepared from pure standard materials or purchased as certified 
solutions. Prepare stock standard solutions in reagent water using 
assayed liquids. Since acrolein and acrylonitrile are lachrymators, 
primary dilutions of these compounds should be prepared in a hood. A 
NIOSH/MESA approved toxic gas respirator should be used when the analyst 
handles high concentrations of such materials.
    6.6.1  Place about 9.8 mL of reagent water into a 10-mL ground glass 
stoppered volumetric flask. For acrolein standards the reagent water 
must be adjusted to pH 4 to 5. Weight the flask to the nearest 0.1 mg.
    6.6.2  Using a 100-L syringe, immediately add two or more 
drops of assayed reference material to the flask, then reweigh. Be sure 
that the drops fall directly into the water without contacting the neck 
of the flask.
    6.6.3  Reweigh, dilute to volume, stopper, then mix by inverting the 
flask several times. Calculate the concentration in g/
L from the net gain in weight. When compound purity is assayed 
to be 96% or greater, the weight can be used without correction to 
calculate the concentration of the stock staldard. Optionally, stock 
standard solutions may be prepared using the pure standard material by 
volumetrically measuring the appropriate amounts and determining the 
weight of the material using the density of the material. Commercially 
prepared stock standards may be used at any concentration if they are 
certified by the manufactaurer or by an independent source.
    6.6.4  Transfer the stock standard solution into a Teflon-sealed 
screw-cap bottle. Store at 4  deg.C and protect from light.
    6.6.5  Prepare fresh standards daily.
    6.7  Secondary dilution standards--Using stock standard solutions, 
prepare secondary dilution standards in reagent water that contain the 
compounds of interest, either singly or mixed together. The secondary 
dilution standards should be prepared at concentrations such that the 
aqueous calibration standards prepared in Section 7.3.1 or 7.4.1 will 
bracket the working range of the analytical system. Secondary dilution 
standards should be prepared daily and stored at 4  deg.C.
    6.8  Quality control check sample concentrate--See Section 8.2.1.

                             7. Calibration

    7.1  Assemble a purge and trap system that meets the specifications 
in Section 5.2. Condition the trap overnight at 180  deg.C by 
backflushing with an inert gas flow of at least 20 mL/min. Condition the 
trap for 10 min once daily prior to use.
    7.2  Connect the purge and trap system to a gas chromatograph. The 
gas chromatograph must be operated using temperature and flow rate 
conditions equivalent to those given in Table 1. Calibrate the purge and 
trap-gas chromatographic system using either the external standard 
technique (Section 7.3) or the internal standard technique (Section 
7.4).
    7.3  External standard calibration procedure:
    7.3.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter by carefully adding 20.0 
L of one or more secondary dilution standards to 100, 500, or 
1000 mL of reagent water. A 25-L syringe with a 0.006 in. ID 
needle should be used for this operation. One of the external standards 
should be at a concentration near, but above, the MDL and the other 
concentrations should correspond to the expected range of concentrations 
found in real samples or should define the working range of the 
detector. These standards must be prepared fresh daily.
    7.3.2  Analyze each calibration standard according to Section 10, 
and tabulate peak height or area responses versus the concentration of 
the standard. The results can be used to prepare a calibration curve for 
each compound. Alternatively, if the ratio of response to concentration 
(calibration factor) is a constant over the working range (< 10% 
relative standard deviation, RSD), linearity through the origin can be 
assumed and the average ratio or calibration factor can be used in place 
of a calibration curve.
    7.4  Internal standard calibration procedure--To use this approach, 
the analyst must select one or more internal standards that are similar 
in analytical behavior to the compounds of interest. The analyst must 
further demonstrate that the measurement of the internal standard is not 
affected by method or matrix interferences. Because of these 
limitations, no internal standard can be suggested that is applicable to 
all samples.
    7.4.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest as described in 
Section 7.3.1.
    7.4.2  Prepare a spiking solution containing each of the internal 
standards using the procedures described in Sections 6.6 and 6.7. It is 
recommended that the secondary dilution standard be prepared at a 
concentration of 15 g/mL of each internal standard compound. 
The addition of 10 L of this standard to 5.0 mL of sample or 
calibration standard would be equivalent to 30 g/L.
    7.4.3  Analyze each calibration standard according to Section 10, 
adding 10 L of internal standard spiking solution directly to 
the syringe (Section 10.4). Tabulate peak height or area responses 
against concentration for each compound and internal standard, and 
calculate response factors (RF) for each compound using Equation 1.

[[Page 59]]



                                                                                                                
                                                                   RF=      (As)(Cis)    (Ais)(Cs)              
                                                                                                                
                                                                                                                

                                                              Equation 1
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Cis=Concentration of the internal standard.
    Cs=Concentration of the parameter to be measured.

If the RF value over the working range is a constant (<10% RSD), the RF 
can be assumed to be invariant and the average RF can be used for 
calculations. Alternatively, the results can be used to plot a 
calibration curve of response ratios, As/Ais, vs. RF.
    7.5  The working calibration curve, calibration factor, or RF must 
be verified on each working day by the measurement of a QC check sample.
    7.5.1  Prepare the QC check sample as described in Section 8.2.2.
    7.5.2  Analyze the QC check sample according to Section 10.
    7.5.3  For each parameter, compare the response (Q) with the 
corresponding calibration acceptance criteria found in Table 2. If the 
responses for all parameters of interest fall within the designated 
ranges, analysis of actual samples can begin. If any individual Q falls 
outside the range, a new calibration curve, calibration factor, or RF 
must be prepared for that parameter according to Section 7.3 or 7.4.

                           8. Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality control program. The minimum requirements of this program 
consist of an initial demonstration of laboratory capability and an 
ongoing analysis of spiked samples to evaluate and document data 
quality. The laboratory must maintain records to document the quality of 
data that is generated. Ongoing data quality checks are compared with 
established performance criteria to determine if the results of analyses 
meet the performance characteristics of the method. When results of 
sample spikes indicate atypical method performance, a quality control 
check standard must be analyzed to confirm that the measurements were 
performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occurring in 
chromatography, the analyst is permitted certain options (detailed in 
Section 10.1) to improve the separations or lower the cost of 
measurements. Each time such a modification is made to the method, the 
analyst is required to repeat the procedure in Section 8.2.
    8.1.3  Each day, the analyst must analyze a reagent water blank to 
demonstrate that interferences from the analytical system are under 
control.
    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 10% of all samples to monitor and evaluate laboratory data 
quality. This procedure is described in Section 8.3.
    8.1.5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 10% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.5.
    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality control (QC) check sample concentrate is required 
containing each parameter of interest at a concentration of 25 
g/mL in reagent water. The QC check sample concentrate must be 
obtained from the U.S. Environmental Protection Agency, Environmental 
Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If 
not available from that source, the QC check sample concentrate must be 
obtained from another external source. If not available from either 
source above, the QC check sample concentrate must be prepared by the 
laboratory using stock standards prepared independently from those used 
for calibration.
    8.2.2  Prepare a QC check sample to contain 50 g/L of each 
parameter by adding 200 L of QC check sample concentrate to 100 
mL of reagent water.
    8.2.3  Analyze four 5-mL aliquots of the well-mixed QC check sample 
according to Section 10.
    8.2.4  Calculate the average recovery (X) in g/L, and the 
standard deviation of the recovery (s) in g/L, for each 
parameter using the four results.
    8.2.5  For each parameter compare s and X with the corresponding 
acceptance criteria for precision and accuracy, respectively, found in 
Table 3. If s and X for all parameters of interest meet the acceptance 
criteria, the system performance is acceptable and analysis of actual 
samples can begin. If either s exceeds the precision limit or X falls 
outside the range for accuracy, the system performance is unacceptable 
for that parameter. Locate and correct the source of the

[[Page 60]]

problem and repeat the test for each compound of interest.
    8.3  The laboratory must, on an ongoing basis, spike at least 10% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing one to ten samples per month, at least one 
spiked sample per month is required.
    8.3.1  The concentration of the spike in the sample should be 
determined as follows:
    8.3.1.1  If, as in compliance monitoring, the concentration of a 
specific parameter in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of a specific parameter in the sample 
is not being checked against a limit specific to that parameter, the 
spike should be at 50 g/L or 1 to 5 times higher than the 
background concentration determined in Section 8.3.2, whichever 
concentration would be larger.
    8.3.2  Analyze one 5-mL sample aliquot to determine the background 
concentration (B) of each parameter. If necessary, prepare a new QC 
check sample concentrate (Section 8.2.1) appropriate for the background 
concentrations in the sample. Spike a second 5-mL sample aliquot with 10 
L of the QC check sample concentrate and analyze it to 
determine the concentration after spiking (A) of each parameter. 
Calculate each percent recovery (P) as 100(A-B)%/T, where T is the known 
true value of the spike.
    8.3.3  Compare the percent recovery (P) for each parameter with the 
corresponding QC acceptance criteria found in Table 3. These acceptance 
criteria were calculated to include an allowance for error in 
measurement of both the background and spike concentrations, assuming a 
spike to background ratio of 5:1. This error will be accounted for to 
the extent that the analyst's spike to background ratio approaches 
5:1.7
    8.3.4  If any individual P falls outside the designated range for 
recovery, that parameter has failed the acceptance criteria. A check 
standard containing each parameter that failed the criteria must be 
analyzed as described in Section 8.4.
    8.4  If any parameter fails the acceptance criteria for recovery in 
Section 8.3, a QC check standard containing each parameter that failed 
must be prepared and analyzed.

    Note: The frequency for the required analysis of a QC check standard 
will depend upon the number of parameters being simultaneously tested, 
the complexity of the sample matrix, and the performance of the 
laboratory.

    8.4.1  Prepare the QC check standard by adding 10 L of QC 
check sample concentrate (Section 8.2.1 or 8.3.2) to 5 mL of reagent 
water. The QC check standard needs only to contain the parameters that 
failed criteria in the test in Section 8.3.
    8.4.2  Analyze the QC check standard to determine the concentration 
measured (A) of each parameter. Calculate each percent recovery 
(Ps) as 100 (A/T)%, where T is the true value of the standard 
concentration.
    8.4.3  Compare the percent recovery (Ps) for each parameter 
with the corresponding QC acceptance criteria found in Table 3. Only 
parameters that failed the test in Section 8.3 need to be compared with 
these criteria. If the recovery of any such parameter falls outside the 
designated range, the laboratory performance for that parameter is 
judged to be out of control, and the problem must be immediately 
identified and corrected. The analytical result for that parameter in 
the unspiked sample is suspect and may not be reported for regulatory 
compliance purposes.
    8.5  As part of the QC program for the laboratory, method accuracy 
for wastewater samples must be assessed and records must be maintained. 
After the analysis of five spiked wastewater samples as in Section 8.3, 
calculate the average percent recovery (P) and the standard deviation of 
the percent recovery (sp). Express the accuracy assessment as a 
percent recovery interval from P-2sp to P+2sp. If P=90% and 
sp=10%, for example, the accuracy interval is expressed as 70-110%. 
Update the accuracy assessment for each parameter on a regular basis 
(e.g. after each five to ten new accuracy measurements).
    8.6  It is recommended that the laboratory adopt additional quality 
assurance practices for use with this method. The specific practices 
that are most productive depend upon the needs of the laboratory and the 
nature of the samples. Field duplicates may be analyzed to assess the 
precision of the environmental measurements. When doubt exists over the 
identification of a peak on the chromatogram, confirmatory techniques 
such as gas chromatography with a dissimilar column or mass spectrometer 
must be used. Whenever possible, the laboratory should analyze standard 
reference materials and participate in relevant performance evaluation 
studies.

            9. Sample Collection, Preservation, and Handling

    9.1  All samples must be iced or refrigerated from the time of 
collection until analysis. If the sample contains free or combined 
chlorine, add sodium thiosulfate preservative (10 mg/40 mL is sufficient 
for up to 5 ppm Cl2) to the empty sample bottle just prior to 
shipping to the sampling site. EPA Methods 330.4 and 330.5 may be used 
for measurement of residual chlorine.8 Field test kits are 
available for this purpose.
    9.2  If acrolein is to be analyzed, collect about 500 mL of sample 
in a clean glass container. Adjust the pH of the sample to 4 to 5

[[Page 61]]

using acid or base, measuring with narrow range pH paper. Samples for 
acrolein analysis receiving no pH adjustment must be analyzed within 3 
days of sampling.
    9.3  Grab samples must be collected in glass containers having a 
total volume of at least 25 mL. Fill the sample bottle just to 
overflowing in such a manner that no air bubbles pass through the sample 
as the bottle is being filled. Seal the bottle so that no air bubbles 
are entrapped in it. If preservative has been added, shake vigorously 
for 1 min. Maintain the hermetic seal on the sample bottle until time of 
analysis.
    9.4  All samples must be analyzed within 14 days of 
collection.3

                              10. Procedure

    10.1  Table 1 summarizes the recommended operating conditions for 
the gas chromatograph. Included in this table are estimated retention 
times and MDL that can be achieved under these conditions. An example of 
the separations achieved by Column 1 is shown in Figure 5. Other packed 
columns, chromatographic conditions, or detectors may be used if the 
requirements of Section 8.2 are met.
    10.2  Calibrate the system daily as described in Section 7.
    10.3  Adjust the purge gas (nitrogen or helium) flow rate to 20 mL-
min. Attach the trap inlet to the purging device, and set the purge and 
trap system to purge (Figure 3). Open the syringe valve located on the 
purging device sample introduction needle.
    10.4  Remove the plunger from a 5-mL syringe and attach a closed 
syringe valve. Open the sample bottle (or standard) and carefully pour 
the sample into the syringe barrel to just short of overflowing. Replace 
the syringe plunger and compress the sample. Open the syringe valve and 
vent any residual air while adjusting the sample volume to 5.0 mL. Since 
this process of taking an aliquot destroys the validity of the sample 
for future analysis, the analyst should fill a second syringe at this 
time to protect against possible loss of data. Add 10.0 L of 
the internal standard spiking solution (Section 7.4.2), if applicable, 
through the valve bore then close the valve.
    10.5  Attach the syringe-syringe valve assembly to the syringe valve 
on the purging device. Open the syringe valves and inject the sample 
into the purging chamber.
    10.6  Close both valves and purge the sample for 15.0  
0.1 min while heating at 85  2  deg.C.
    10.7  After the 15-min purge time, attach the trap to the 
chromatograph, adjust the purge and trap system to the desorb mode 
(Figure 4), and begin to temperature program the gas chromatograph. 
Introduce the trapped materials to the GC column by rapidly heating the 
trap to 180  deg.C while backflushing the trap with an inert gas between 
20 and 60 mL/min for 1.5 min.
    10.8  While the trap is being desorbed into the gas chromatograph, 
empty the purging chamber using the sample introduction syringe. Wash 
the chamber with two 5-mL flushes of reagent water.
    10.9  After desorbing the sample for 1.5 min, recondition the trap 
by returning the purge and trap system to the purge mode. Wait 15 s then 
close the syringe valve on the purging device to begin gas flow through 
the trap. The trap temperature should be maintained at 210  deg.C. After 
approximately 7 min, turn off the trap heater and open the syringe valve 
to stop the gas flow through the trap. When the trap is cool, the next 
sample can be analyzed.
    10.10  Identify the parameters in the sample by comparing the 
retention times of the peaks in the sample chromatogram with those of 
the peaks in standard chromatograms. The width of the retention time 
window used to make identifications should be based upon measurements of 
actual retention time variations of standards over the course of a day. 
Three times the standard deviation of a retention time for a compound 
can be used to calculate a suggested window size; however, the 
experience of the analyst should weigh heavily in the interpretation of 
chromatograms.

                            11. Calculations

    11.1  Determine the concentration of individual compounds in the 
sample.
    11.1.1  If the external standard calibration procedure is used, 
calculate the concentration of the parameter being measured from the 
peak response using the calibration curve or calibration factor 
determined in Section 7.3.2.
    11.1.2  If the internal standard calibration procedure is used, 
calculate the concentration in the sample using the response factor (RF) 
determined in Section 7.4.3 and Equation 2.

                                                                                                                
                                                                          (As)(Cis)                             
                                          Concentration (g/  = -------------                           
                                                      L)                  (Ais)(RF)                             
                                                                                                                

                                                              Equation 2
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Cis=Concentration of the internal standard.

    11.2  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

                         12. Method Performance

    12.1  The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported

[[Page 62]]

with 99% confidence that the value is above zero.1 The MDL 
concentrations listed in Table 1 were obtained using reagent 
water.9 The MDL actually achieved in a given analysis will vary 
depending on instrument sensitivity and matrix effects.
    12.2  This method is recommended for the concentration range from 
the MDL to 1,000 x MDL. Direct aqueous injection techniques should be 
used to measure concentration levels above 1,000 x MDL.
    12.3  In a single laboratory (Battelle-Columbus), the average 
recoveries and standard deviations presented in Table 2 were 
obtained.9 Seven replicate samples were analyzed at each spike 
level.

                               References

    1. 40 CFR part 136, appendix B.
    2. Bellar, T.A., and Lichtenberg, J.J. ``Determining Volatile 
Organics at Microgram-per-Litre-Levels by Gas Chromatography,'' Journal 
American Water Works Association, 66, 739 (1974).
    3. ``Evaluate Test Procedures for Acrolein and Acrylonitrile,'' 
Special letter report for EPA Project 4719-A, U.S. Environmental 
Protection Agency, Environmental Monitoring and Support Laboratory, 
Cincinnati, Ohio 45268, 27 June 1979.
    4. ``Carcinogens--Working With Carcinogens,'' Department of Health, 
Education, and Welfare, Public Health Service, Center for Disease 
Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    5. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR 
part 1910), Occupational Safety and Health Administration, OSHA 2206 
(Revised, January 1976).
    6. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent 
Recovery Data,'' American Laboratory, 15, 58-63 (1983).
    8. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for 
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory, Cincinnati, Ohio 45268, March 1979.
    9. ``Evaluation of Method 603 (Modified),'' EPA-600/4-84-ABC, 
National Technical Information Service, PB84-, Springfield, Virginia 
22161, Nov. 1984.

     Table 1--Chromatographic Conditions and Method Detection Limits    
------------------------------------------------------------------------
                                     Retention time (min)      Method   
                                   ------------------------   detection 
             Parameter                                          limit   
                                     Column 1    Column 2   (g/
                                                                 L)     
------------------------------------------------------------------------
Acrolein..........................     10.6         8.2          0.7    
Acrylonitrile.....................     12.7         9.8          0.5    
------------------------------------------------------------------------
Column 1 conditions: Porapak-QS (80/100 mesh) packed in a 10 ft  x  2 mm
  ID glass or stainless steel column with helium carrier gas at 30 mL/  
  min flow rate. Column temperature held isothermal at 110 C for 1.5 min
  (during desorption), then heated as rapidly as possible to 150 C and  
  held for 20 min; column bakeout at 190 C for 10 min.\9\               
Column 2 conditions: Chromosorb 101 (60/80 mesh) packed in a 6 ft. x 0.1
  in. ID glass or stainless steel column with helium carrier gas at 40  
  mL/min flow rate. Column temperature held isothermal at 80 deg.C for 4
  min, then programmed at 50 deg.C/min to 120 deg.C and held for 12 min.


                          Table 2--Single Laboratory Accuracy and Precision--Method 603                         
----------------------------------------------------------------------------------------------------------------
                                                                              Average      Standard             
                                                    Sample    Spike conc.    recovery      deviation    Average 
                    Parameter                       matrix   (g/  (g/  (g/   percent 
                                                                  L)            L)            L)        recovery
----------------------------------------------------------------------------------------------------------------
Acrolein.........................................        RW         5.0            5.2           0.2         104
                                                         RW        50.0           51.4           0.7         103
                                                       POTW         5.0            4.0           0.2          80
                                                       POTW        50.0           44.4           0.8          89
                                                         IW         5.0            0.1           0.1           2
                                                         IW       100.0            9.3           1.1           9
Acrylonitrile....................................        RW         5.0            4.2           0.2          84
                                                         RW        50.0           51.4           1.5         103
                                                       POTW        20.0           20.1           0.8         100
                                                       POTW       100.0          101.3           1.5         101
                                                         IW        10.0            9.1           0.8          91
                                                         IW       100.0          104.0           3.2         104
----------------------------------------------------------------------------------------------------------------
 ARW=Reagent water.                                                                                             
 APOTW=Prechlorination secondary effluent from a municipal sewage treatment plant.                              
 AIW=Industrial wastewater containing an unidentified acrolein reactant.                                        


[[Page 63]]


                          Table 3--Calibration and QC Acceptance Criteria--Method 603 a                         
----------------------------------------------------------------------------------------------------------------
                                                              Range for Q   Limit for S   Range for X           
                         Parameter                           (g/  (g/  (g/  Range for
                                                                  L)            L)            L)       P, Ps (%)
----------------------------------------------------------------------------------------------------------------
Acrolein...................................................    45.9-54.1         4.6       42.9-60.1      88-118
Acrylonitrile..............................................    41.2-58.8         9.9       33.1-69.9      71-135
----------------------------------------------------------------------------------------------------------------
a=Criteria were calculated assuming a QC check sample concentration of 50 g/L.9                        
Q=Concentration measured in QC check sample, in g/L (Section 7.5.3).                                   
s=Standard deviation of four recovery measurements, in g/L (Section 8.2.4).                            
X=Average recovery for four recovery measurements, in g/L (Section 8.2.4).                             
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).                                                 


[[Page 64]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.008


[[Page 65]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.009


[[Page 66]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.010


[[Page 67]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.011


[[Page 68]]

                           Method 604--Phenols

                        1. Scope and Application

    1.1  This method covers the determination of phenol and certain 
substituted phenols. The following parameters may be determined by this 
method:

------------------------------------------------------------------------
                                                    STORET              
                    Parameter                         No.      CAS No.  
------------------------------------------------------------------------
4-Chloro-3-methylphenol..........................     34452      59-50-7
2--Chlorophenol..................................     34586      95-57-8
2,4-Dichlorophenol...............................     34601     120-83-2
2,4-Dimethylphenol...............................     34606     105-67-9
2,4-Dinitrophenol................................     34616      51-28-5
2-Methyl-4,6-dinitrophenol.......................     34657     534-52-1
2-Nitrophenol....................................     34591      88-75-5
4-Nitrophenol....................................     34646     100-02-7
Pentachlorophenol................................     39032      87-86-5
Phenol...........................................     34694     108-95-2
2,4,6-Trichlorophenol............................     34621      88-06-2
------------------------------------------------------------------------
                                                                        

    1.2  This is a flame ionization detector gas chromatographic (FIDGC) 
method applicable to the determination of the compounds listed above in 
municipal and industrial discharges as provided under 40 CFR 136.1. When 
this method is used to analyze unfamiliar samples for any or all of the 
compounds above, compound identifications should be supported by at 
least one additional qualitative technique. This method describes 
analytical conditions for derivatization, cleanup, and electron capture 
detector gas chromatography (ECDGC) that can be used to confirm 
measurements made by FIDGC. Method 625 provides gas chromatograph/mass 
spectrometer (GC/MS) conditions appropriate for the qualitative and 
quantitative confirmation of results for all of the parameters listed 
above, using the extract produced by this method.
    1.3 The method detection limit (MDL, defined in Section 14.1) \1\ 
for each parameter is listed in Table 1. The MDL for a specific 
wastewater may differ from those listed, depending upon the nature of 
interferences in the sample matrix. The MDL listed in Table 1 for each 
parameter was achieved with a flame ionization detector (FID). The MDLs 
that were achieved when the derivatization cleanup and electron capture 
detector (ECD) were employed are presented in Table 2.
    1.4  Any modification of this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5.
    1.5  This method is restricted to use by or under the supervision of 
analysts experienced in the use of a gas chromatograph and in the 
interpretation of gas chromatograms. Each analyst must demonstrate the 
ability to generate acceptable results with this method using the 
procedure described in Section 8.2.

                          2. Summary of Method

    2.1  A measured volume of sample, approximately 1-L, is acidified 
and extracted with methylene chloride using a separatory funnel. The 
methylene chloride extract is dried and exchanged to 2-propanol during 
concentration to a volume of 10 mL or less. The extract is separated by 
gas chromatography and the phenols are then measured with an FID.\2\
    2.2  A preliminary sample wash under basic conditions can be 
employed for samples having high general organic and organic base 
interferences.
    2.3  The method also provides for a derivatization and column 
chromatography cleanup procedure to aid in the elimination of 
interferences.2,3 The derivatives are analyzed by ECDGC.

                            3. Interferences

    3.1  Method interferences may be caused by contaminants in solvents, 
reagents, glassware, and other sample processing hardware that lead to 
discrete artifacts and/or elevated baselines in gas chromatograms. All 
of these materials must be routinely demonstrated to be free from 
interferences under the conditions of the analysis by running laboratory 
reagent blanks as described in Section 8.1.3.
    3.1.1  Glassware must be scrupulously cleaned.\4\ Clean all 
glassware as soon as possible after use by rinsing with the last solvent 
used in it. Solvent rinsing should be followed by detergent washing with 
hot water, and rinses with tap water and distilled water. The glassware 
should then be drained dry, and heated in a muffle furnace at 400  deg.C 
for 15 to 30 min. Some thermally stable materials, such as PCBs, may not 
be eliminated by this treatment. Solvent rinses with acetone and 
pesticide quality hexane may be substituted for the muffle furnace 
heating. Thorough rinsing with such solvents usually eliminates PCB 
interference. Volumetric ware should not be heated in a muffle furnace. 
After drying and cooling, glassware should be sealed and stored in a 
clean environment to prevent any accumulation of dust or other 
contaminants. Store inverted or capped with aluminum foil.
    3.1.2  The use of high purity reagents and solvents helps to 
minimize interference problems. Purification of solvents by distillation 
in all-glass systems may be required.
    3.2  Matrix interferences may be caused by contaminants that are 
coextracted from the sample. The extent of matrix interferences will 
vary considerably from source to source, depending upon the nature and 
diversity of the industrial complex or municipality being sampled. The 
derivatization cleanup procedure in Section 12 can be used to overcome

[[Page 69]]

many of these interferences, but unique samples may require additional 
cleanup approaches to achieve the MDL listed in Tables 1 and 2.
    3.3  The basic sample wash (Section 10.2) may cause significantly 
reduced recovery of phenol and 2,4-dimethylphenol. The analyst must 
recognize that results obtained under these conditions are minimum 
concentrations.

                                4. Safety

    4.1  The toxicity or carcinogenicity of each reagent used in this 
mothod has not been precisely defined; however, each chemical compound 
should be treated as a potential health hazard. From this viewpoint, 
exposure to these chemicals must be reduced to the lowest possible level 
by whatever means available. The laboratory is responsible for 
maintaining a current awareness file of OSHA regulations regarding the 
safe handling of the chemicals specified in this method. A reference 
file of material data handling sheets should also be made available to 
all personnel involved in the chemical analysis. Additional references 
to laboratory safety are available and have been identified 5--7 
for the information of analyst.
    4.2  Special care should be taken in handling pentafluorobenzyl 
bromide, which is a lachrymator, and 18-crown-6-ether, which is highly 
toxic.

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete or composite sampling.
    5.1.1  Grab sample bottle--1-L or 1-qt, amber glass, fitted with a 
screw cap lined with Teflon. Foil may be substituted for Teflon if the 
sample is not corrosive. If amber bottles are not available, protect 
samples from light. The bottle and cap liner must be washed, rinsed with 
acetone or methylene chloride, and dried before use to minimize 
contamination.
    5.1.2  Automatic sampler (optional)--The sampler must incorporate 
glass sample containers for the collection of a minimum of 250 mL of 
sample. Sample containers must be kept refrigerated at 4  deg.C and 
protected from light during compositing. If the sampler uses a 
peristaltic pump, a minimum length of compressible silicone rubber 
tubing may be used. Before use, however, the compressible tubing should 
be thoroughly rinsed with methanol, followed by repeated rinsings with 
distilled water to minimize the potential for contamination of the 
sample. An integrating flow meter is required to collect flow 
proportional composites.
    5.2  Glassware (All specifications are suggested. Catalog numbers 
are included for illustration only.):
    5.2.1  Separatory funnel--2-L, with Teflon stopcock.
    5.2.2  Drying column--Chromatographic column, 400 mm long x 19 mm 
ID, with coarse frit filter disc.
    5.2.3  Chromatographic column--100 mm long x 10 mm ID, with Teflon 
stopcock.
    5.2.4  Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes 
K-570050-1025 or equivalent). Calibration must be checked at the volumes 
employed in the test. Ground glass stopper is used to prevent 
evaporation of extracts.
    5.2.5  Evaporative flask, Kuderna-Danish--500-mL (Kontes K-570001-
0500 or equivalent). Attach to concentrator tube with springs.
    5.2.6  Snyder column, Kuderna-Danish--Three-ball macro (Kontes K-
503000-0121 or equivalent).
    5.2.7  Snyder column, Kuderna-Danish--Two-ball micro (Kontes K-
569001-0219 or equivalent).
    5.2.8  Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
    5.2.9  Reaction flask--15 to 25-mL round bottom flask, with standard 
tapered joint, fitted with a water-cooled condenser and U-shaped drying 
tube containing granular calcium chloride.
    5.3  Boiling chips--Approximately 10/40 mesh. Heat to 400  deg.C for 
30 min or Soxhlet extract with methylene chloride.
    5.4  Water bath--Heated, with concentric ring cover, capable of 
temperature control (2 deg.C). The bath should be used in a 
hood.
    5.5  Balance--Analytical, capable of accurately weighting 0.0001 g.
    5.6  Gas chromatograph--An analytical system complete with a 
temperature programmable gas chromatograph suitable for on-column 
injection and all required accessories including syringes, analytical 
columns, gases, detector, and strip-chart recorder. A data system is 
recommended for measuring peak areas.
    5.6.1  Column for underivatized phenols--1.8 m long x 2 mm ID glass, 
packed with 1% SP-1240DA on Supelcoport (80/100 mesh) or equivalent. 
This column was used to develop the method performance statements in 
Section 14. Guidelines for the use of alternate column packings are 
provided in Section 11.1.
    5.6.2  Column for derivatized phenols--1.8 m long x 2 mm ID glass, 
packed with 5% OV-17 on Chromosorb W-AW-DMCS (80/100 mesh) or 
equivalent. This column has proven effective in the analysis of 
wastewaters for derivatization products of the parameters listed in the 
scope (Section 1.1), and was used to develop the method performance 
statements in Section 14. Guidelines for the use of alternate column 
packings are provided in Section 11.1.
    5.6.3  Detectors--Flame ionization and electron capture detectors. 
The FID is used when determining the parent phenols. The ECD is used 
when determining the derivatized phenols. Guidelines for the use of

[[Page 70]]

alternatve detectors are provided in Section 11.1.

                               6. Reagents

    6.1  Reagent water--Reagent water is defined as a water in which an 
interferent is not observed at the MDL of the parameters of interest.
    6.2  Sodium hydroxide solution (10 N)--Dissolve 40 g of NaOH (ACS) 
in reagent water and dilute to 100 mL.
    6.3  Sodium hydroxide solution (1 N)--Dissolve 4 g of NaOH (ACS) in 
reagent water and dilute to 100 mL.
    6.4  Sodium sulfate--(ACS) Granular, anhydrous. Purify by heating at 
400 deg.C for 4 h in a shallow tray.
    6.5  Sodium thiosulfate--(ACS) Granular.
    6.6  Sulfuric acid (1+1)--Slowly, add 50 mL of H2SO4 (ACS, 
sp. gr. 1.84) to 50 mL of reagent water.
    6.7  Sulfuric acid (1 N)--Slowly, add 58 mL of H2SO4 (ACS, 
sp. gr. 1.84) to reagent water and dilute to 1 L.
    6.8  Potassium carbonate--(ACS) Powdered.
    6.9  Pentafluorobenzyl bromide (-Bromopentafluorotoluene)--
97% minimum purity.
    Note: This chemical is a lachrymator. (See Section 4.2.)
    6.10  18-crown-6-ether (1,4,7,10,13,16-Hexaoxacyclooctadecane)--98% 
minimum purity.
    Note: This chemical is highly toxic.
    6.11  Derivatization reagent--Add 1 mL of pentafluorobenzyl bromide 
and 1 g of 18-crown-6-ether to a 50-mL volumetric flask and dilute to 
volume with 2-propanol. Prepare fresh weekly. This operation should be 
carried out in a hood. Store at 4  deg.C and protect from light.
    6.12  Acetone, hexane, methanol, methylene chloride, 2-propanol, 
toluene--Pesticide quality or equivalent.
    6.13  Silica gel--100/200 mesh, Davison, grade-923 or equivalent. 
Activate at 130  deg.C overnight and store in a desiccator.
    6.14  Stock standard solutions (1.00 g/L)--Stock 
standard solutions may be prepared from pure standard materials or 
purchased as certified solutions.
    6.14.1  Prepare stock standard solutions by accurately weighing 
about 0.0100 g of pure material. Dissolve the material in 2-propanol and 
dilute to volume in a 10-mL volumetric flask. Larger volumes can be used 
at the convenience of the analyst. When compound purity is assayed to be 
96% or greater, the weight can be used without correction to calculate 
the concentration of the stock standard. Commercially prepared stock 
standards can be used at any concentration if they are certified by the 
manufacturer or by an independent source.
    6.14.2  Transfer the stock standard solutions into Teflon-sealed 
screw-cap bottles. Store at 4  deg.C and protect from light. Stock 
standard solutions should be checked frequently for signs of degradation 
or evaporation, especially just prior to preparing calibration standards 
from them.
    6.14.3  Stock standard solutions must be replaced after six months, 
or sooner if comparison with check standards indicates a problem.
    6.15  Quality control check sample concentrate--See Section 8.2.1.

                             7. Calibration

    7.1  To calibrate the FIDGC for the anaylsis of underivatized 
phenols, establish gas chromatographic operating conditions equivalent 
to those given in Table 1. The gas chromatographic system can be 
calibrated using the external standard technique (Section 7.2) or the 
internal standard technique (Section 7.3).
    7.2  External standard calibration procedure for FIDGC:
    7.2.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask and diluting to volume 
with 2-propanol. One of the external standards should be at a 
concentration near, but above, the MDL (Table 1) and the other 
concentrations should correspond to the expected range of concentrations 
found in real samples or should define the working range of the 
detector.
    7.2.2  Using injections of 2 to 5 l, analyze each 
calibration standard according to Section 11 and tabulate peak height or 
area responses against the mass injected. The results can be used to 
prepare a calibration curve for each compound. Alternatively, if the 
ratio of response to amount injected (calibration factor) is a constant 
over the working range (<10% relative standard deviation, RSD), 
linearity through the origin can be assumed and the average ratio or 
calibration factor can be used in place of a calibration curve.
    7.3  Internal standard calibration procedure for FIDGC--To use this 
approach, the analyst must select one or more internal standards that 
are similar in analytical behavior to the compounds of interest. The 
analyst must further demonstrate that the measurement of the internal 
standard is not affected by method or matrix interferences. Because of 
these limitations, no internal standard can be suggested that is 
applicable to all samples.
    7.3.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask. To each calibration 
standard, add a known constant amount of one or more internal standards, 
and dilute to volume with 2-propanol. One of the standards

[[Page 71]]

should be at a concentration near, but above, the MDL and the other 
concentrations should correspond to the expected range of concentrations 
found in real samples or should define the working range of the 
detector.
    7.3.2  Using injections of 2 to 5 L, analyze each 
calibration standard according to Section 11 and tabulate peak height or 
area responses against concentration for each compound and internal 
standard. Calculate response factors (RF) for each compound using 
Equation 1.

                                                                                                                
                                                                   RF=      (As)(Cis)    (Ais)(Cs)              
                                                                                                                

                                                              Equation 1
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Cis=Concentration of the internal standard (g/L).

    Cs=Concentration of the parameter to be measured (g/
L).
    If the RF value over the working range is a constant (<10% RSD), the 
RF can be assumed to be invariant and the average RF can be used for 
calculations. Alternatively, the results can be used to plot a 
calibration curve of response ratios, As/Ais, vs. RF.
    7.4  The working calibration curve, calibration factor, or RF must 
be verified on each working day by the measurement of one or more 
calibration standards. If the response for any parameter varies from the 
predicted response by more than 15%, a new calibration curve 
must be prepared for that compound.
    7.5  To calibrate the ECDGC for the analysis of phenol derivatives, 
establish gas chromatographic operating conditions equivalent to those 
given in Table 2.
    7.5.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask and diluting to volume 
with 2-propanol. One of the external standards should be at a 
concentration near, but above, the MDL (Table 2) and the other 
concentrations should correspond to the expected range of concentrations 
found in real samples or should define the working range of the 
detector.
    7.5.2  Each time samples are to be derivatized, simultaneously treat 
a 1-mL aliquot of each calibration standard as described in Section 12.
    7.5.3  After derivatization, analyze 2 to 5 L of each 
column eluate collected according to the method beginning in Section 
12.8 and tabulate peak height or area responses against the calculated 
equivalent mass of underivatized phenol injected. The results can be 
used to prepare a calibration curve for each compound.
    7.6  Before using any cleanup procedure, the analyst must process a 
series of calibration standards through the procedure to validate 
elution patterns and the absence of interferences from the reagents.

                           8. Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality control program. The minimum requirements of this program 
consist of an initial demonstration of laboratory capability and an 
ongoing analysis of spiked samples to evaluate and document data 
quality. The laboratory must maintain records to document the quality of 
data that is generated. Ongoing data quality checks are compared with 
established performance criteria to determine if the results of analyses 
meet the performance characteristics of the method. When results of 
sample spikes indicate atypical method performance, a quality control 
check standard must be analyzed to confirm that the measurements were 
performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occurring in 
chromatography, the analyst is permitted certain options (detailed in 
Sections 10.6 and 11.1) to improve the separations or lower the cost of 
measurements. Each time such a modification is made to the method, the 
analyst is required to repeat the procedure in Section 8.2.
    8.1.3  Before processing any samples the analyst must analyze a 
reagent water blank to demonstrate that interferences from the 
analytical system and glassware are under control. Each time a set of 
samples is extracted or reagents are changed a reagent water blank must 
be processed as a safeguard against laboratory contamination.
    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 10% of all samples to monitor and evaluate laboratory data 
quality. This procedure is described in Section 8.3.
    8.1.5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 10% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.5.

[[Page 72]]

    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality control (QC) check sample concentrate is required 
containing each parameter of interest at a concentration of 100 
g/mL in 2-propanol. The QC check sample concentrate must be 
obtained from the U.S. Environmental Protection Agency, Environmental 
Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If 
not available from that source, the QC check sample concentrate must be 
obtained from another external source. If not available from either 
source above, the QC check sample concentrate must be prepared by the 
laboratory using stock standards prepared independently from those used 
for calibration.
    8.2.2  Using a pipet, prepare QC check samples at a concentration of 
100 g/L by adding 1.00 mL of QC check sample concentrate to 
each of four 1-L aliquots of reagent water.
    8.2.3  Analyze the well-mixed QC check samples according to the 
method beginning in Section 10.
    8.2.4  Calculate the average recovery (X) in g/L, and the 
standard deviation of the recovery (s) in g/L, for each 
parameter using the four results.
    8.2.5  For each parameter compare s and X with the corresponding 
acceptance criteria for precision and accuracy, respectively, found in 
Table 3. If s and X for all parameters of interest meet the acceptance 
criteria, the system performance is acceptable and analysis of actual 
samples can begin. If any individual s exceeds the precision limit or 
any individual X falls outside the range for accuracy, the system 
performance is unacceptable for that parameter.
    Note: The large number of parameters in Talbe 3 present a 
substantial probability that one or more will fail at least one of the 
acceptance criteria when all parameters are analyzed.
    8.2.6  When one or more of the parameters tested fail at least one 
of the acceptance criteria, the analyst must proceed according to 
Section 8.2.6.1 or 8.2.6.2.
    8.2.6.1  Locate and correct the source of the problem and repeat the 
test for all parameters of interest beginning with Section 8.2.2.
    8.2.6.2  Beginning with Section 8.2.2, repeat the test only for 
those parameters that failed to meet criteria. Repeated failure, 
however, will confirm a general problem with the measurement system. If 
this occurs, locate and correct the source of the problem and repeat the 
test for all compounds of interest beginning with Section 8.2.2.
    8.3  The laboratory must, on an ongoing basis, spike at least 10% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing one to ten samples per month, at least one 
spiked sample per month is required.
    8.3.1  The concentration of the spike in the sample should be 
determined as follows:
    8.3.1.1  If, as in compliance monitoring, the concentration of a 
specific parameter in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of a specific parameter in the sample 
is not being checked against a limit specific to that parameter, the 
spike should be at 100 g/L or 1 to 5 times higher than the 
background concentration determined in Section 8.3.2, whichever 
concentration would be larger.
    8.3.1.3  If it is impractical to determine background levels before 
spiking (e.g., maximum holding times will be exceeded), the spike 
concentration should be (1) the regulatory concentration limit, if any, 
or, if none, (2) the larger of either 5 times higher than the expected 
background concentration or 100 g/L.
    8.3.2  Analyze one sample aliquot to determine the background 
concentration (B) of each parameter. If necessary, prepare a new QC 
check sample concentrate (Section 8.2.1) appropriate for the background 
concentrations in the sample. Spike a second sample aliquot with 1.0 mL 
of the QC check sample concentrate and analyze it to determine the 
concentration after spiking (A) of each parameter. Calculate each 
percent recovery (P) as 100(A-B)%/T, where T is the known true value of 
the spike.
    8.3.3  Compare the percent recovery (P) for each parameter with the 
corresponding QC acceptance criteria found in Table 3. These acceptance 
criteria were calculated to include an allowance for error in 
measurement of both the background and spike concentrations, assuming a 
spike to background ratio of 5:1. This error will be accounted for to 
the extent that the analyst's spike to background ratio approaches 
5:1.8 If spiking was performed at a concentration lower than 100 
g/L, the analyst must use either the QC acceptance criteria in 
Table 3, or optional QC acceptance criteria calculated for the specific 
spike concentration. To calculate optional acceptance criteria for the 
recovery of a parameter: (1) Calculate accuracy (X') using the equation 
in Table 4, substituting the spike concentration (T) for C; (2) 
calculate overall precision (S') using the equation in Table 4, 
substituting X' for X; (3) calculate the range for recovery at the spike 
concentration as (100 X'/T)2.44(100 S'/T)%.8
    8.3.4  If any individual P falls outside the designated range for 
recovery, that parameter has failed the acceptance criteria. A check 
standard containing each parameter that failed the criteria must be 
analyzed as described in Section 8.4.

[[Page 73]]

    8.4  If any parameter fails the acceptance criteria for recovery in 
Section 8.3, a QC check standard containing each parameter that failed 
must be prepared and analyzed.
    Note: The frequency for the required analysis of a QC check standard 
will depend upon the number of parameters being simultaneously tested, 
the complexity of the sample matrix, and the performance of the 
laboratory.
    8.4.1  Prepare the QC check standard by adding 1.0 mL of QC check 
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The 
QC check standard needs only to contain the parameters that failed 
criteria in the test in Section 8.3.
    8.4.2  Analyze the QC check standard to determine the concentration 
measured (A) of each parameter. Calculate each percent recovery 
(Ps) as 100 (A/T)%, where T is the true value of the standard 
concentration.
    8.4.3  Compare the percent recovery (Ps) for each parameter 
with the corresponding QC acceptance criteria found in Table 3. Only 
parameters that failed the test in Section 8.3 need to be compared with 
these criteria. If the recovery of any such parameter falls outside the 
designated range, the laboratory performance for that parameter is 
judged to be out of control, and the problem must be immediately 
identified and corrected. The analytical result for that parameter in 
the unspiked sample is suspect and may not be reported for regulatory 
compliance purposes.
    8.5  As part of the QC program for the laboratory, method accuracy 
for wastewater samples must be assessed and records must be maintained. 
After the analysis of five spiked wastewater samples as in Section 8.3, 
calculate the average percent recovery (P) and the standard deviation of 
the percent recovery (sp). Express the accuracy assessment as a 
percent recovery interval from P-2sp to P+2sp. If P=90% and 
sp=10%, for example, the accuracy interval is expressed as 70-110%. 
Update the accuracy assessment for each parameter on a regular basis 
(e.g. after each five to ten new accuracy measurements).
    8.6.  It is recommended that the laboratory adopt additional quality 
assurance practices for use with this method. The specific practices 
that are most productive depend upon the needs of the laboratory and the 
nature of the samples. Field duplicates may be analyzed to assess the 
precision of the environmental measurements. When doubt exists over the 
identification of a peak on the chromatogram, confirmatory techniques 
such as gas chromatography with a dissimilar column, specific element 
detector, or mass spectrometer must be used. Whenever possible, the 
laboratory should analyze standard reference materials and participate 
in relevant performance evaluation studies.

            9. Sample Collection, Preservation, and Handling

    9.1  Grab samples must be collected in glass containers. 
Conventional sampling practices 9 should be followed, except that 
the bottle must not be prerinsed with sample before collection. 
Composite samples should be collected in refrigerated glass containers 
in accordance with the requirements of the program. Automatic sampling 
equipment must be as free as possible of Tygon tubing and other 
potential sources of contamination.
    9.2  All samples must be iced or refrigerated at 4  deg.C from the 
time of collection until extraction. Fill the sample bottles and, if 
residual chlorine is present, add 80 mg of sodium thiosulfate per liter 
of sample and mix well. EPA Methods 330.4 and 330.5 may be used for 
measurement of residual chlorine.10 Field test kits are available 
for this purpose.
    9.3  All samples must be extracted within 7 days of collection and 
completely analyzed within 40 days of extraction.2

                          10. Sample Extraction

    10.1  Mark the water meniscus on the side of sample bottle for later 
determination of sample volume. Pour the entire sample into a 2-L 
separatory funnel.
    10.2  For samples high in organic content, the analyst may solvent 
wash the sample at basic pH as prescribed in Sections 10.2.1 and 10.2.2 
to remove potential method interferences. Prolonged or exhaustive 
contact with solvent during the wash may result in low recovery of some 
of the phenols, notably phenol and 2,4-dimethylphenol. For relatively 
clean samples, the wash should be omitted and the extraction, beginning 
with Section 10.3, should be followed.
    10.2.1  Adjust the pH of the sample to 12.0 or greater with sodium 
hydroxide solution.
    10.2.2  Add 60 mL of methylene chloride to the sample by shaking the 
funnel for 1 min with periodic venting to release excess pressure. 
Discard the solvent layer. The wash can be repeated up to two additional 
times if significant color is being removed.
    10.3  Adjust the sample to a pH of 1 to 2 with sulfuric acid.
    10.4  Add 60 mL of methylene chloride to the sample bottle, seal, 
and shake 30 s to rinse the inner surface. Transfer the solvent to the 
separatory funnel and extract the sample by shaking the funnel for 2 
min. with periodic venting to release excess pressure. Allow the organic 
layer to separate from the water phase for a minimum of 10 min. If the 
emulsion interface between layers is more than one-third the volume of 
the solvent layer, the analyst must employ mechanical techniques to 
complete the phase separation. The optimum technique depends upon the 
sample, but may include stirring, filtration

[[Page 74]]

of the emulsion through glass wool, centrifugation, or other physical 
methods. Collect the methylene chloride extract in a 250-mL Erlenmeyer 
flask.
    10.5  Add a second 60-mL volume of methylene chloride to the sample 
bottle and repeat the extraction procedure a second time, combining the 
extracts in the Erlenmeyer flask. Perform a third extraction in the same 
manner.
    10.6  Assemble a Kuderna-Danish (K-D) concentrator by attaching a 
10-mL concentrator tube to a 500-mL evaporative flask. Other 
concentration devices or techniques may be used in place of the K-D 
concentrator if the requirements of Section 8.2 are met.
    10.7  Pour the combined extract through a solvent-rinsed drying 
column containing about 10 cm of anhydrous sodium sulfate, and collect 
the extract in the K-D concentrator. Rinse the Erlenmeyer flask and 
column with 20 to 30 mL of methylene chloride to complete the 
quantitative transfer.
    10.8  Add one or two clean boiling chips to the evaporative flask 
and attach a three-ball Snyder column. Prewet the Snyder column by 
adding about 1 mL of methylene chloride to the top. Place the K-D 
apparatus on a hot water bath (60 to 65  deg.C) so that the concentrator 
tube is partially immersed in the hot water, and the entire lower 
rounded surface of the flask is bathed with hot vapor. Adjust the 
vertical position of the apparatus and the water temperature as required 
to complete the concentration in 15 to 20 min. At the proper rate of 
distillation the balls of the column will actively chatter but the 
chambers will not flood with condensed solvent. When the apparent volume 
of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain 
and cool for at least 10 min.
    10.9  Increase the temperature of the hot water bath to 95 to 100 
deg.C. Remove the Synder column and rinse the flask and its lower joint 
into the concentrator tube with 1 to 2 mL of 2-propanol. A 5-mL syringe 
is recommended for this operation. Attach a two-ball micro-Snyder column 
to the concentrator tube and prewet the column by adding about 0.5 mL of 
2-propanol to the top. Place the micro-K-D apparatus on the water bath 
so that the concentrator tube is partially immersed in the hot water. 
Adjust the vertical position of the apparatus and the water temperature 
as required to complete concentration in 5 to 10 min. At the proper rate 
of distillation the balls of the column will actively chatter but the 
chambers will not flood. When the apparent volume of liquid reaches 2.5 
mL, remove the K-D apparatus and allow it to drain and cool for at least 
10 min. Add an additional 2 mL of 2-propanol through the top of the 
micro-Snyder column and resume concentrating as before. When the 
apparent volume of liquid reaches 0.5 mL, remove the K-D apparatus and 
allow it to drain and cool for at least 10 min.
    10.10  Remove the micro-Snyder column and rinse its lower joint into 
the concentrator tube with a minimum amount of 2-propanol. Adjust the 
extract volume to 1.0 mL. Stopper the concentrator tube and store 
refrigerated at 4  deg.C if further processing will not be performed 
immediately. If the extract will be stored longer than two days, it 
should be transferred to a Teflon-sealed screw-cap vial. If the sample 
extract requires no further cleanup, proceed with FIDGC analysis 
(Section 11). If the sample requires further cleanup, proceed to Section 
12.
    10.11  Determine the original sample volume by refilling the sample 
bottle to the mark and transferring the liquid to a 1000-mL graduated 
cylinder. Record the sample volume to the nearest 5 mL.

            11. Flame Ionization Detector Gas Chromatography

    11.1  Table 1 summarizes the recommended operating conditions for 
the gas chromatograph. Included in this table are retention times and 
MDL that can be achieved under these conditions. An example of the 
separations achieved by this column is shown in Figure 1. Other packed 
or capillary (open-tubular) columns, chromatographic conditions, or 
detectors may be used if the requirements of Section 8.2 are met.
    11.2  Calibrate the system daily as described in Section 7.
    11.3  If the internal standard calibration procedure is used, the 
internal standard must be added to the sample extract and mixed 
thoroughly immediately before injection into the gas chromatograph.
    11.4  Inject 2 to 5 L of the sample extract or standard 
into the gas chromatograph using the solvent-flush technique.11 
Smaller (1.0 L) volumes may be injected if automatic devices 
are employed. Record the volume injected to the nearest 0.05 L, 
and the resulting peak size in area or peak height units.
    11.5  Identify the parameters in the sample by comparing the 
retention times of the peaks in the sample chromatogram with those of 
the peaks in standard chromatograms. The width of the retention time 
window used to make identifications should be based upon measurements of 
actual retention time variations of standards over the course of a day. 
Three times the standard deviation of a retention time for a compound 
may be used to calculate a suggested window size; however, the 
experience of the analyst should weigh heavily in the interpretation of 
chromatograms.
    11.6  If the response for a peak exceeds the working range of the 
system, dilute the extract and reanalyze.

[[Page 75]]

    11.7  If the measurement of the peak response is prevented by the 
presence of interferences, an alternative gas chromatographic procedure 
is required. Section 12 describes a derivatization and column 
chromatographic procedure which has been tested and found to be a 
practical means of analyzing phenols in complex extracts.

   12. Derivatization and Electron Capture Detector Gas Chromatography

    12.1  Pipet a 1.0-mL aliquot of the 2-propanol solution of standard 
or sample extract into a glass reaction vial. Add 1.0 mL of derivatizing 
reagent (Section 6.11). This amount of reagent is sufficient to 
derivatize a solution whose total phenolic content does not exceed 0.3 
mg/mL.
    12.2  Add about 3 mg of potassium carbonate to the solution and 
shake gently.
    12.3  Cap the mixture and heat it for 4 h at 80  deg.C in a hot 
water bath.
    12.4  Remove the solution from the hot water bath and allow it to 
cool.
    12.5  Add 10 mL of hexane to the reaction flask and shake vigorously 
for 1 min. Add 3.0 mL of distilled, deionized water to the reaction 
flask and shake for 2 min. Decant a portion of the organic layer into a 
concentrator tube and cap with a glass stopper.
    12.6  Place 4.0 g of silica gel into a chromatographic column. Tap 
the column to settle the silica gel and add about 2 g of anhydrous 
sodium sulfate to the top.
    12.7  Preelute the column with 6 mL of hexane. Discard the eluate 
and just prior to exposure of the sodium sulfate layer to the air, pipet 
onto the column 2.0 mL of the hexane solution (Section 12.5) that 
contains the derivatized sample or standard. Elute the column with 10.0 
mL of hexane and discard the eluate. Elute the column, in order, with: 
10.0 mL of 15% toluene in hexane (Fraction 1); 10.0 mL of 40% toluene in 
hexane (Fraction 2); 10.0 mL of 75% toluene in hexane (Fraction 3); and 
10.0 mL of 15% 2-propanol in toluene (Fraction 4). All elution mixtures 
are prepared on a volume: volume basis. Elution patterns for the 
phenolic derivatives are shown in Table 2. Fractions may be combined as 
desired, depending upon the specific phenols of interest or level of 
interferences.
    12.8  Analyze the fractions by ECDGC. Table 2 summarizes the 
recommended operating conditions for the gas chromatograph. Included in 
this table are retention times and MDL that can be achieved under these 
conditions. An example of the separations achieved by this column is 
shown in Figure 2.
    12.9  Calibrate the system daily with a minimum of three aliquots of 
calibration standards, containing each of the phenols of interest that 
are derivatized according to Section 7.5.
    12.10  Inject 2 to 5 L of the column fractions into the gas 
chromatograph using the solvent-flush technique. Smaller (1.0 
L) volumes can be injected if automatic devices are employed. 
Record the volume injected to the nearest 0.05 L, and the 
resulting peak size in area or peak height units. If the peak response 
exceeds the linear range of the system, dilute the extract and 
reanalyze.

                            13. Calculations

    13.1  Determine the concentration of individual compounds in the 
sample analyzed by FIDGC (without derivatization) as indicated below.
    13.1.1  If the external standard calibration procedure is used, 
calculate the amount of material injected from the peak response using 
the calibration curve or calibration factor determined in Section 7.2.2. 
The concentration in the sample can be calculated from Equation 2.

                                                                                                                
                                                                           (A)(Vt)                              
                                        Concentration (g/  = -----------------                         
                                                    L)                     (Vi)(Vs)                             
                                                                                                                

                                                              Equation 2
where:
    A=Amount of material injected (ng).
    Vi=Volume of extract injected (L).
    Vt=Volume of total extract (L).
    Vs=Volume of water extracted (mL).

    13.1.2  If the internal standard calibration procedure is used, 
calculate the concentration in the sample using the response factor (RF) 
determined in Section 7.3.2 and Equation 3.

                                                                                                                
                                                                           (As)(Is)                             
                                        Concentration (g/  = -----------------                         
                                                    L)                  (Ais)(RF)(Vo)                           
                                                                                                                

                                                              Equation 3
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Is=Amount of internal standard added to each extract 
(g).
    Vo=Volume of water extracted (L).

    13.2  Determine the concentration of individual compounds in the 
sample analyzed by derivatization and ECDGC according to Equation 4.

                                                                                                                
                                                                        (A)(Vt)(B)(D)                           
                                        Concentration (g/  = -----------------                         
                                                    L)                  (Vi)(Vs)(C)(E)                          
                                                                                                                

                                                              Equation 4
where:
    A=Mass of underivatized phenol represented by area of peak in sample 
chromatogram, determined from calibration curve in Section 7.5.3 (ng).
    Vi=Volume of eluate injected (L).

[[Page 76]]

    Vt=Total volume of column eluate or combined fractions from 
which Vi was taken (L).
    Vs=Volume of water extracted in Section 10.10 (mL).
    B=Total volume of hexane added in Section 12.5 (mL).
    C=Volume of hexane sample solution added to cleanup column in 
Section 12.7 (mL).
    D=Total volume of 2-propanol extract prior to derivatization (mL).
    E=Volume of 2-propanol extract carried through derivatization in 
Section 12.1 (mL).

    13.3  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

                         14. Method Performance

    14.1  The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the value is above zero.1 The MDL concentrations 
listed in Tables 1 and 2 were obtained using reagent water.12 
Similar results were achieved using representative wastewaters. The MDL 
actually achieved in a given analysis will vary depending on instrument 
sensitivity and matrix effects.
    14.2  This method was tested by 20 laboratories using reagent water, 
drinking water, surface water, and three industrial wastewaters spiked 
as six concentrations over the range 12 to 450 g/L.13 
Single operator precision, overall precision, and method accuracy were 
found to be directly related to the concentration of the parameter and 
essentially independent of the sample matrix. Linear equations to 
describe these relationships for a flame ionization detector are 
presented in Table 4.

                               References

    1. 40 CFR part 136, appendix B.
    2. ``Determination of Phenols in Industrial and Municipal 
Wastewaters,'' EPA 600/4-84-ABC, National Technical Information Service, 
PBXYZ, Springfield, Virginia 22161, November 1984.
    3. Kawahara, F. K. ``Microdetermination of Derivatives of Phenols 
and Mercaptans by Means of Electron Capture Gas Chromatography,'' 
Analytical Chemistry, 40, 1009 (1968).
    4. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard 
Practices for Preparation of Sample Containers and for Preservation of 
Organic Constituents,'' American Society for Testing and Materials, 
Philadelphia.
    5. ``Carcinogens--Working With Carcinogens,'' Department of Health, 
Education, and Welfare, Public Health Service, Center for Disease 
Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    6. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR 
part 1910), Occupational Safety and Health Administration, OSHA 2206 
(Revised, January 1976).
    7. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    8. Provost, L. P., and Elder, R. S. ``Interpretation of Percent 
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44 
used in the equation in Section 8.3.3 is two times the value 1.22 
derived in this report.)
    9. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard 
Practices for Sampling Water,'' American Society for Testing and 
Materials, Philadelphia.
    10. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methmds for 
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory, Cincinnati, Ohio 45268, March 1979.
    11. Burke, J. A. ``Gas Chromatography for Pesticide Residue 
Analysis; Some Practical Aspects,'' Journal of the Association of 
Official Analytical Chemists, 48, 1037 (1965).
    12. ``Development of Detection Limits, EPA Method 604, Phenols,'' 
Special letter report for EPA Contract 68-03-2625, U.S. Environmental 
Protection Agency, Environmental Monitoring and Support Laboratory, 
Cincinnati, Ohio 45268.
    13. ``EPA Method Study 14 Method 604-Phenols,'' EPA 600/4-84-044, 
National Technical Information Service, PB84-196211, Springfield, 
Virginia 22161, May 1984.

     Table 1--Chromatographic Conditions and Method Detection Limits    
------------------------------------------------------------------------
                                                               Method   
                                                              detection 
                   Parameter                     Retention      limit   
                                                time (min)  (g/
                                                                 L)     
------------------------------------------------------------------------
2-Chlorophenol................................        1.70          0.31
2-Nitrophenol.................................        2.00          0.45
Phenol........................................        3.01          0.14
2,4-Dimethylphenol............................        4.03          0.32
2,4-Dichlorophenol............................        4.30          0.39
2,4,6-Trichlorophenol.........................        6.05          0.64
4-Chloro-3-methylphenol.......................        7.50          0.36
2,4-Dinitrophenol.............................       10.00         13.0 
2-Methyl-4,6-dinitrophenol....................       10.24         16.0 
Pentachlorophenol.............................       12.42          7.4 
4-Nitrophenol.................................       24.25          2.8 
------------------------------------------------------------------------
Column conditions: Supelcoport (80/100 mesh) coated with 1% SP-1240DA   
  packed in a 1.8 m long x 2 mm ID glass column with nitrogen carrier   
  gas at 30 mL/min flow rate. Column temperature was 80 C at injection, 
  programmed immediately at 8 C/min to 150 C final temperature. MDL were
  determined with an FID.                                               


[[Page 77]]


          Table 2--Silica Gel Fractionation and Electron Capture Gas Chromatography of PFBB Derivatives         
----------------------------------------------------------------------------------------------------------------
                                                                 Percent recovery by                   Method   
                                                                     fraction a          Retention    detection 
                      Parent compound                       ----------------------------    time        limit   
                                                                                           (min)    (g/
                                                               1      2      3      4                    L)     
----------------------------------------------------------------------------------------------------------------
2-Chlorophenol.............................................  .....     90      1  .....        3.3         0.58 
2-Nitrophenol..............................................  .....  .....      9     90        9.1         0.77 
Phenol.....................................................  .....     90     10  .....        1.8         2.2  
2,4-Dimethylphenol.........................................  .....     95      7  .....        2.9         0.63 
2,4-Dichlorophenol.........................................  .....     95      1  .....        5.8         0.68 
2,4,6-Trichlorophenol......................................     50     50  .....  .....        7.0         0.58 
4-Chloro-3-methylphenol....................................  .....     84     14  .....        4.8         1.8  
Pentachlorophenol..........................................     75     20  .....  .....       28.8         0.59 
4-Nitrophenol..............................................  .....  .....      1     90       14.0         0.70 
----------------------------------------------------------------------------------------------------------------
Column conditions: Chromosorb W-AW-DMCS (80/100 mesh) coated with 5% OV-17 packed in a 1.8 m long x 2.0 mm ID   
  glass column with 5% methane/95% argon carrier gas at 30 mL/min flow rate. Column temperature held isothermal 
  at 200 C. MDL were determined with an ECD.                                                                    
                                                                                                                
a Eluant composition:                                                                                           
    Fraction 1--15% toluene in hexane.                                                                          
    Fraction 2--40% toluene in hexane.                                                                          
    Fraction 3--75% toluene in hexane.                                                                          
    Fraction 4--15% 2-propanol in toluene.                                                                      


                                   Table 3--QC Acceptance Criteria--Method 604                                  
----------------------------------------------------------------------------------------------------------------
                                                                                        Range for X             
                                                            Test conc.    Limit for s  (g/   Range for 
                        Parameter                          (g/  (g/       L)          P, Ps   
                                                                L)            L)                      (percent) 
----------------------------------------------------------------------------------------------------------------
4-Chloro-3-methylphenol..................................        100            16.6     56.7-113.4       49-122
2-Chlorophenol...........................................        100            27.0     54.1-110.2       38-126
2,4-Dichlorophenol.......................................        100            25.1     59.7-103.3       44-119
2,4-Dimethylphenol.......................................        100            33.3     50.4-100.0       24-118
4,6-Dinitro-2-methylphenol...............................        100            25.0     42.4-123.6       30-136
2,4-Dinitrophenol........................................        100            36.0     31.7-125.1       12-145
2-Nitrophenol............................................        100            22.5     56.6-103.8       43-117
4-Nitrophenol............................................        100            19.0     22.7-100.0       13-110
Pentachlorophenol........................................        100            32.4     56.7-113.5       36-134
Phenol...................................................        100            14.1     32.4-100.0       23-108
2,4,6-Trichlorophenol....................................        100            16.6     60.8-110.4       53-119
----------------------------------------------------------------------------------------------------------------
s--Standard deviation of four recovery measurements, in g/L (Section 8.2.4).                           
X--Average recovery for four recovery measurements, in g/L (Section 8.2.4).                            
P, Ps--Percent recovery measured (Section 8.3.2, Section 8.4.2).                                                
                                                                                                                
Note: These criteria are based directly upon the method performance data in Table 4. Where necessary, the limits
  for recovery have been broadened to assure applicability of the limits to concentrations below those used to  
  develop Table 4.                                                                                              


                Table 4--Method Accuracy and Precision as Functions of Concentration--Method 604                
----------------------------------------------------------------------------------------------------------------
                                                            Accuracy, as      Single Analyst        Overall     
                       Parameter                            recovery, X'      precision, sr'     precision, S'  
                                                           (g/L)     (g/L)     (g/L) 
----------------------------------------------------------------------------------------------------------------
4-Chloro-3-methylphenol................................         0.87C-1.97         0.11X-0.21         0.16X+1.41
2-Chlorophenol.........................................         0.83C-0.84         0.18X+0.20         0.21X+0.75
2,4-Dichlorophenol.....................................         0.81C+0.48         0.17X-0.02         0.18X+0.62
2,4-Dimethylphenol.....................................         0.62C-1.64         0.30X-0.89         0.25X+0.48
4,6-Dinitro-2-methylphenol.............................         0.84C-1.01         0.15X+1.25         0.19X+5.85
2,4-Dinitrophenol......................................         0.80C-1.58         0.27X-1.15         0.29X+4.51
2-Nitrophenol..........................................         0.81C-0.76         0.15X+0.44         0.14X+3.84
4-Nitrophenol..........................................         0.46C+0.18         0.17X+2.43         0.19X+4.79
Pentachlorophenol......................................         0.83C+2.07         0.22X-0.58         0.23X+0.57
Phenol.................................................         0.43C+0.11         0.20X-0.88         0.17X+0.77
2,4,6-Trichlorophenol..................................         0.86C-0.40         0.10X+0.53         0.13X+2.40
----------------------------------------------------------------------------------------------------------------
X'=Expected recovery for one or more measurements of a sample containing a concentration of C, in g/L. 
sr'=Expected single analyst standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
S'=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
C=True value for the concentration, in g/L.                                                            
X=Average recovery found for measurements of samples containing a concentration of C, in g/L.          


[[Page 78]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.012


[[Page 79]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.013


[[Page 80]]

                         Method 605--Benzidines

                        1. Scope and Application

    1.1  This method covers the determination of certain benzidines. The 
following parameters can be determined by this method:

------------------------------------------------------------------------
                   Parameter                     Storet No     CAS No.  
------------------------------------------------------------------------
Benzidine.....................................        39120      92-87-5
3,3-Dichlorobenzidine.........................        34631      91-94-1
------------------------------------------------------------------------

    1.2  This is a high performance liquid chromatography (HPLC) method 
applicable to the determination of the compounds listed above in 
municipal and industrial discharges as provided under 40 CFR 136.1. When 
this method is used to analyze unfamiliar samples for the compounds 
above, identifications should be supported by at least one additional 
qualitative technique. This method describes electrochemical conditions 
at a second potential which can be used to confirm measurements made 
with this method. Method 625 provides gas chromatograph/mass 
spectrometer (GC/MS) conditions appropriate for the qualitative and 
quantitative confirmation of results for the parameters listed above, 
using the extract produced by this method.
    1.3  The method detection limit (MDL, defined in Section 14.1) 
1 for each parameter is listed in Table 1. The MDL for a specific 
wastewater may differ from those listed, depending upon the nature of 
the interferences in the sample matrix.
    1.4  Any modification of this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5.
    1.5  This method is restricted to use by or under the supervision of 
analysts experienced in the use of HPLC instrumentation and in the 
interpretation of liquid chromatograms. Each analyst must demonstrate 
the ability to generate acceptable results with this method using the 
procedure described in Section 8.2.

                          2. Summary of Method

    2.1  A measured volume of sample, approximately 1-L, is extracted 
with chloroform using liquid-liquid extractions in a separatory funnel. 
The chloroform extract is extracted with acid. The acid extract is then 
neutralized and extracted with chloroform. The final chloroform extract 
is exchanged to methanol while being concentrated using a rotary 
evaporator. The extract is mixed with buffer and separated by HPLC. The 
benzidine compounds are measured with an electrochemical detector.2
    2.2  The acid back-extraction acts as a general purpose cleanup to 
aid in the elimination of interferences.

                            3. Interferences

    3.1  Method interferences may be caused by contaminants in solvents, 
reagents, glassware, and other sample processing hardware that lead to 
discrete artifacts and/or elevated baselines in chromatograms. All of 
these materials must be routinely demonstrated to be free from 
interferences under the conditions of the analysis by running laboratory 
reagent blanks as described in Section 8.1.3.
    3.1.1  Glassware must be scrupulously cleaned.3 Clean all 
glassware as soon as possible after use by rinsing with the last solvent 
used in it. Solvent rinsing should be followed by detergent washing with 
hot water, and rinses with tap water and distilled water. The glassware 
should then be drained dry, and heated in a muffle furnace at 400  deg.C 
for 15 to 30 min. Some thermally stable materials may not be eliminated 
by this treatment. Solvent rinses with acetone and pesticide quality 
hexane may be substituted for the muffle furnace heating. Volumetric 
ware should not be heated in a muffle furnace. After drying and cooling, 
glassware should be sealed and stored in a clean environment to prevent 
any accumulation of dust or other contaminants. Store inverted or capped 
with aluminum foil.
    3.1.2  The use of high purity reagents and solvents helps to 
minimize interference problems. Purification of solvents by distillation 
in all-glass systems may be required.
    3.2  Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary 
considerably from source to source, depending upon the nature and 
diversity of the industrial complex or municipality being sampled. The 
cleanup procedures that are inherent in the extraction step are used to 
overcome many of these interferences, but unique samples may require 
additional cleanup approaches to achieve the MDL listed in Table 1.
    3.3  Some dye plant effluents contain large amounts of components 
with retention times closed to benzidine. In these cases, it has been 
found useful to reduce the electrode potential in order to eliminate 
interferences and still detect benzidine. (See Section 12.7.)

                                4. Safety

    4.1  The toxicity or carcinogenicity of each reagent used in this 
method has not been precisely defined; however, each chemical compound 
should be treated as a potential health harzard. From this viewpoint, 
exposure to these chemicals must be reduced to the lowest possible level 
by whatever means available. The laboratory is responsible for 
maintaining a current awareness file of OSHA regulations regarding the 
safe handling of the chemicals specified in this method. A reference 
file of material data handling

[[Page 81]]

sheets should also be made available to all personnel involved in the 
chemical analysis. Additional references to laboratory safety are 
available and have been identified 4-6 for the information of the 
analyst.
    4.2  The following parameters covered by this method have been 
tentatively classified as known or suspected, human or mammalian 
carcinogens: benzidine and 3,3'-dichlorobenzidine. Primary standards of 
these toxic compounds should be prepared in a hood. A NIOSH/MESA 
approved toxic gas respirator should be worn when the analyst handles 
high concentrations of these toxic compounds.
    4.3  Exposure to chloroform should be minimized by performing all 
extractions and extract concentrations in a hood or other well-
ventiliated area.

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete or composite sampling.
    5.1.1  Grab sample bottle--1-L or 1-qt, amber glass, fitted with a 
screw cap lined with Teflon. Foil may be substituted for Teflon if the 
sample is not corrosive. If amber bottles are not available, protect 
samples from light. The bottle and cap liner must be washed, rinsed with 
acetone or methylene chloride, and dried before use to minimize 
contamination.
    5.1.2  Automatic sampler (optional)--The sampler must incorporate 
glass sample containers for the collection of a minimum of 250 mL of 
sample. Sample containers must be kept refrigerated at 4 deg.C and 
protected from light during compositing. If the sampler uses a 
peristaltic pump, a minimum length of compressible silicone rubber 
tubing may be used. Before use, however, the compressible tubing should 
be thoroughly rinsed with methanol, followed by repeated rinsings with 
distilled water to minimize the potential for contamination of the 
sample. An integrating flow meter is required to collect flow 
proportional composites.
    5.2  Glassware (All specifications are suggested):
    5.2.1  Separatory funnels--2000, 1000, and 250-mL, with Teflon 
stopcock.
    5.2.2  Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
    5.2.3  Rotary evaporator.
    5.2.4  Flasks--Round bottom, 100-mL, with 24/40 joints.
    5.2.5  Centrifuge tubes--Conical, graduated, with Teflon-lined screw 
caps.
    5.2.6  Pipettes--Pasteur, with bulbs.
    5.3  Balance--Analytical, capable of accurately weighing 0.0001 g.
    5.4  High performance liquid chromatograph (HPLC)--An analytical 
system complete with column supplies, high pressure syringes, detector, 
and compatible recorder. A data system is recommended for measuring peak 
areas and retention times.
    5.4.1  Solvent delivery system--With pulse damper, Altex 110A or 
equivalent.
    5.4.2  Injection valve (optional)--Waters U6K or equivalent.
    5.4.3  Electrochemical detector--Bioanalytical Systems LC-2A with 
glassy carbon electrode, or equivalent. This detector has proven 
effective in the analysis of wastewaters for the parameters listed in 
the scope (Section 1.1), and was used to develop the method performance 
statements in Section 14. Guidelines for the use of alternate detectors 
are provided in Section 12.1.
    5.4.4  Electrode polishing kit--Princeton Applied Research Model 
9320 or equivalent.
    5.4.5  Column--Lichrosorb RP-2, 5 micron particle diameter, in a 25 
cm  x  4.6 mm ID stainless steel column. This column was used to develop 
the method performance statements in Section 14. Guidelines for the use 
of alternate column packings are provided in Section 12.1.

                               6. Reagents

    6.1  Reagent water--Reagent water is defined as a water in which an 
interferent is not observed at the MDL of the parameters of interest.
    6.2  Sodium hydroxide solution (5 N)--Dissolve 20 g of NaOH (ACS) in 
reagent water and dilute to 100 mL.
    6.3  Sodium hydroxide solution (1 M)--Dissolve 40 g of NaOH (ACS) in 
reagent water and dilute to 1 L.
    6.4  Sodium thiosulfate--(ACS) Granular.
    6.5  Sodium tribasic phosphate (0.4 M)--Dissolve 160 g of trisodium 
phosphate decahydrate (ACS) in reagent water and dilute to 1 L.
    6.6  Sulfuric acid (1+1)--Slowly, add 50 mL of H2SO4 (ACS, 
sp. gr. 1.84) to 50 mL of reagent water.
    6.7  Sulfuric acid (1 M)--Slowly, add 58 mL of H2SO4 (ACS, 
sp. gr. 1.84) to reagent water and dilute to 1 L.
    6.8  Acetate buffer (0.1 M, pH 4.7)--Dissolve 5.8 mL of glacial 
acetic acid (ACS) and 13.6 g of sodium acetate trihydrate (ACS) in 
reagent water which has been purified by filtration through a RO-4 
Millipore System or equivalent and dilute to 1 L.
    6.9  Acetonitrile, chloroform (preserved with 1% ethanol), 
methanol--Pesticide quality or equivalent.
    6.10  Mobile phase--Place equal volumes of filtered acetonitrile 
(Millipore type FH filter or equivalent) and filtered acetate buffer 
(Millipore type GS filter or equivalent) in a narrow-mouth, glass 
container and mix thoroughly. Prepare fresh weekly. Degas daily by 
sonicating under vacuum, by heating an stirring, or by purging with 
helium.
    6.11  Stock standard solutions (1.00 g/L)--Stock 
standard solutions may be prepared from pure standard materials or 
purchased as certified solutions.

[[Page 82]]

    6.11.1  Prepare stock standard solutions by accurately weighing 
about 0.0100 g of pure material. Dissolve the material in methanol and 
dilute to volume in a 10-mL volumetric flask. Larger volumes can be used 
at the convenience of the analyst. When compound purity is assayed to be 
96% or greater, the weight can be used without correction to calculate 
the concentration of the stock standard. Commercially prepared stock 
standards can be used at any concentration if they are certified by the 
manufacturer or by an independent source.
    6.11.2  Transfer the stock standard solutions into Teflon-sealed 
screw-cap bottles. Store at 4  deg.C and protect from light. Stock 
standard solutions should be checked frequently for signs of degradation 
or evaporation, especially just prior to preparing calibration standards 
from them.
    6.11.3  Stock standard solutions must be replaced after six months, 
or sooner if comparison with check standards indicates a problem.
    6.12  Quality control check sample concentrate--See Section 8.2.1.

                             7. Calibration

    7.1  Establish chromatographic operating conditions equivalent to 
those given in Table 1. The HPLC system can be calibrated using the 
external standard technique (Section 7.2) or the internal standard 
technique (Section 7.3).
    7.2  External standard calibration procedure:
    7.2.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask and diluting to volume 
with mobile phase. One of the external standards should be at a 
concentration near, but above, the MDL (Table 1) and the other 
concentrations should correspond to the expected range of concentrations 
found in real samples or should define the working range of the 
detector.
    7.2.2  Using syringe injections of 5 to 25 L or a constant 
volume injection loop, analyze each calibration standard according to 
Section 12 and tabulate peak height or area responses against the mass 
injected. The results can be used to prepare a calibration curve for 
each compound. Alternatively, if the ratio of response to amount 
injected (calibration factor) is a constant over the working range (<10% 
relative standard deviation, RSD), linearity through the origin can be 
assumed and the average ratio or calibration factor can be used in place 
of a calibration curve.
    7.3  Internal standard calibration procedure--To use this approach, 
the analyst must select one or more internal standards that are similar 
in analytical behavior to the compounds of interest. The analyst must 
further demonstrate that the measurement of the internal standard is not 
affected by method or matrix interferences. Because of these 
limitations, no internal standard can be suggested that is applicable to 
all samples.
    7.3.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask. To each calibration 
standard, add a known constant amount of one or more internal standards, 
and dilute to volume with mobile phase. One of the standards should be 
at a concentration near, but above, the MDL and the other concentrations 
should correspond to the expected range of concentrations found in real 
samples or should define the working range of the detector.
    7.3.2  Using syringe injections of 5 to 25 L or a constant 
volume injection loop, analyze each calibration standard according to 
Section 12 and tabulate peak height or area responses against 
concentration for each compound and internal standard. Calculate 
response factors (RF) for each compound using Equation 1.

                                                                                                                
                                                                   RF=      (As)(Cis)    (Ais)(Cs)              
                                                                                                                

                                                              Equation 1
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Cis=Concentration of the internal standard (g/L).
    Cs=Concentration of the parameter to be measured (g/
L).

    If the RF value over the working range is a constant (<10% RSD), the 
RF can be assumed to be invariant and the average RF can be used for 
calculations. Alternatively, the results can be used to plot a 
calibration curve of response ratios, As/Ais, vs. RF.
    7.4  The working calibration curve, calibration factor, or RF must 
be verified on each working day by the measurement of one or more 
calibration standards. If the response for any parameter varies from the 
predicted response by more than 15%, a new calibration curve 
must be prepared for that compound. If serious loss of response occurs, 
polish the electrode and recalibrate.
    7.5  Before using any cleanup procedure, the analyst must process a 
series of calibration standards through the procedure to validate 
elution patterns and the absence of interferences from the reagents.

                           8. Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality control program. The minimum requirements of

[[Page 83]]

this program consist of an initial demonstration of laboratory 
capability and an ongoing analysis of spiked samples to evaluate and 
document data quality. The laboratory must maintain records to document 
the quality of data that is generated. Ongoing data quality checks are 
compared with established performance criteria to determine if the 
results of analyses meet the performance characteristics of the method. 
When results of sample spikes indicate atypical method performance, a 
quality control check standard must be analyzed to confirm that the 
measurements were performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occurring in 
chromatography, the analyst is permitted certain options (detailed in 
Sections 10.9, 11.1, and 12.1) to improve the separations or lower the 
cost of measurements. Each time such a modification is made to the 
method, the analyst is required to repeat the procedure in Section 8.2.
    8.1.3  Before processing any samples, the analyst must analyze a 
reagent water blank to demonstrate that interferences from the 
analytical system and glassware are under control. Each time a set of 
samples is extracted or reagents are changed, a reagent water blank must 
be processed as a safeguard against laboratory contamination.
    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 10% of all samples to monitor and evaluate laboratory data 
quality. This procedure is described in Section 8.3.
    8.1.5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 10% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.5.
    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality control (QC) check sample concentrate is required 
containing benzidine and/or 3,3'-dichlorobenzidine at a concentration of 
50 g/mL each in methanol. The QC check sample concentrate must 
be obtained from the U.S. Environmental Protection Agency, Environmental 
Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If 
not available from that source, the QC check sample concentrate must be 
obtained from another external source. If not available from either 
source above, the QC check sample concentrate must be prepared by the 
laboratory using stock standards prepared independently from those used 
for calibration.
    8.2.2  Using a pipet, prepare QC check samples at a concentration of 
50 g/L by adding 1.00 mL of QC check sample concentrate to each 
of four 1-L-L aliquots of reagent water.
    8.2.3  Analyze the well-mixed QC check samples according to the 
method beginning in Section 10.
    8.2.4  Calculate the average recovery (X) in g/L, and the 
standard deviation of the recovery (s) in g/L, for each 
parameter using the four results.
    8.2.5  For each parameter compare s and X with the corresponding 
acceptance criteria for precision and accuracy, respectively, found in 
Table 2. If s and X for all parameters of interest meet the acceptance 
criteria, the system performance is acceptable and analysis of actual 
samples can begin. If any individual s exceeds the precision limit or 
any individual X falls outside the range for accuracy, the system 
performance is unacceptable for that parameter. Locate and correct the 
source of the problem and repeat the test for all parameters of interest 
beginning with Section 8.2.2.
    8.3  The laboratory must, on an ongoing basis, spike at least 10% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing one to ten samples per month, at least one 
spiked sample per month is required.
    8.3.1  The concentration of the spike in the sample should be 
determined as follows:
    8.3.1.1  If, as in compliance monitoring, the concentration of a 
specific parameter in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of a specific parameter in the sample 
is not being checked against a limit specific to that parameter, the 
spike should be at 50 g/L or 1 to 5 times higher than the 
background concentration determined in Section 8.3.2, whichever 
concentration would be larger.
    8.3.1.3  If it is impractical to determine background levels before 
spiking (e.g., maximum holding times will be exceeded), the spike 
concentration should be (1) the regulatory concentration limit, if any; 
or, if none (2) the larger of either 5 times higher than the expected 
background concentration or 50 g/L.
    8.3.2  Analyze one sample aliquot to determine the background 
concentration (B) of each parameter. If necessary, prepare a new QC 
check sample concentrate (Section 8.2.1)

[[Page 84]]

appropriate for the background concentrations in the sample. Spike a 
second sample aliquot with 1.0 mL of the QC check sample concentrate and 
analyze it to determine the concentration after spiking (A) of each 
parameter. Calculate each percent recovery (P) as 100(A-B)%/T, where T 
is the known true value of the spike.
    8.3.3  Compare the percent recovery (P) for each parameter with the 
corresponding QC acceptance criteria found in Table 2. These acceptance 
criteria were calculated to include an allowance for error in 
measurement of both the background and spike concentrations, assuming a 
spike to background ratio of 5:1. This error will be accounted for to 
the extent that the analyst's spike to background ratio approaches 
5:1.\7\ If spiking was performed at a concentration lower than 50 
g/L, the analyst must use either the QC acceptance criteria in 
Table 2, or optional QC acceptance criteria calculated for the specific 
spike concentration. To calculate optional acceptance criteria for the 
recovery of a parameter: (1) Calculate accuracy (X') using the equation 
in Table 3, substituting the spike concentration (T) for C; (2) 
calculate overall precision (S') using the equation in Table 3, 
substituting X' for X; (3) calculate the range for recovery at the spike 
concentration as (100 X'/T)2.44(100 S'/T)%.\7\
    8.3.4  If any individual P falls outside the designated range for 
recovery, that parameter has failed the acceptance criteria. A check 
standard containing each parameter that failed the criteria must be 
analyzed as described in Section 8.4.
    8.4  If any parameter fails the acceptance criteria for recovery in 
Section 8.3, a QC check standard containing each parameter that failed 
must be prepared and analyzed.
    Note: The frequency for the required analysis of a QC check standard 
will depend upon the number of parameters being simultaneously tested, 
the complexity of the sample matrix, and the performance of the 
laboratory.
    8.4.1  Prepare the QC check standard by adding 1.0 mL of QC check 
sample concentrate (Sections 8.2.1 or 8.3.2) to 1 L of reagent water. 
The QC check standard needs only to contain the parameters that failed 
criteria in the test in Section 8.3.
    8.4.2  Analyze the QC check standard to determine the concentration 
measured (A) of each parameter. Calculate each percent recovery 
(Ps) as 100 (A/T)%, where T is the true value of the standard 
concentration.
    8.4.3  Compare the percent recovery (Ps) for each parameter 
with the corresponding QC acceptance criteria found in Table 2. Only 
parameters that failed the test in Section 8.3 need to be compared with 
these criteria. If the recovery of any such parameter falls outside the 
designated range, the laboratory performance for that parameter is 
judged to be out of control, and the problem must be immediately 
identified and corrected. The analytical result for that parameter in 
the unspiked sample is suspect and may not be reported for regulatory 
compliance purposes.
    8.5  As part of the QC program for the laboratory, method accuracy 
for wastewater samples must be assessed and records must be maintained. 
After the analysis of five spiked wastewater samples as in Section 8.3, 
calculate the average percent recovery (P) and the standard deviation of 
the percent recovery (sp). Express the accuracy assessment as a 
percent recovery interval from P-2sp to P+2sp. If P=90% and 
sp=10%, for example, the accuracy interval is expressed as 70-110%. 
Update the accuracy assessment for each parameter on a regular basis 
(e.g. after each five to ten new accuracy measurements).
    8.6  It is recommended that the laboratory adopt additional quality 
assurance practices for use with this method. The specific practices 
that are most productive depend upon the needs of the laboratory and the 
nature of the samples. Field duplicates may be analyzed to assess the 
precision of the environmental measurements. When doubt exists over the 
identification of a peak on the chromatogram, confirmatory techniques 
such as HPLC with a dissimilar column, gas chromatography, or mass 
spectrometer must be used. Whenever possible, the laboratory should 
analyze standard reference materials and participate in relevant 
performance evaluation studies.

            9. Sample Collection, Preservation, and Handling

    9.1  Grab samples must be collected in glass containers. 
Conventional sampling practices\8\ should be followed, except that the 
bottle must not be prerinsed with sample before collection. Composite 
samples should be collected in refrigerated glass containers in 
accordance with the requirements of the program. Automatic sampling 
equipment must be as free as possible of Tygon tubing and other 
potential sources of contamination.
    9.2  All samples must be iced or refrigerated at 4 deg.C and stored 
in the dark from the time of collection until extraction. Both benzidine 
and 3,3'-dichlorobenzidine are easily oxidized. Fill the sample bottles 
and, if residual chlorine is present, add 80 mg of sodium thiosulfate 
per liter of sample and mix well. EPA Methods 330.4 and 330.5 may be 
used for measurement of residual chlorine.\9\ Field test kits are 
available for this purpose. After mixing, adjust the pH of the sample to 
a range of 2 to 7 with sulfuric acid.
    9.3  If 1,2-diphenylhydrazine is likely to be present, adjust the pH 
of the sample to 4.0 0.2 to prevent rearrangement to 
benzidine.
    9.4  All samples must be extracted within 7 days of collection. 
Extracts may be held up to 7 days before analysis, if stored under an 
inert (oxidant free) atmosphere.\2\ The extract should be protected from 
light.

[[Page 85]]

                          10. Sample Extraction

    10.1  Mark the water meniscus on the side of the sample bottle for 
later determination of sample volume. Pour the entire sample into a 2-L 
separatory funnel. Check the pH of the sample with wide-range pH paper 
and adjust to within the range of 6.5 to 7.5 with sodium hydroxide 
solution or sulfuric acid.
    10.2  Add 100 mL of chloroform to the sample bottle, seal, and shake 
30 s to rinse the inner surface. (Caution: Handle chloroform in a well 
ventilated area.) Transfer the solvent to the separatory funnel and 
extract the sample by shaking the funnel for 2 min with periodic venting 
to release excess pressure. Allow the organic layer to separate from the 
water phase for a minimum of 10 min. If the emulsion interface between 
layers is more than one-third the volume of the solvent layer, the 
analyst must employ mechanical techniques to complete the phase 
separation. The optimum technique depends upon the sample, but may 
include stirring, filtration of the emulsion through glass wool, 
centrifugation, or other physical methods. Collect the chloroform 
extract in a 250-mL separatory funnel.
    10.3  Add a 50-mL volume of chloroform to the sample bottle and 
repeat the extraction procedure a second time, combining the extracts in 
the separatory funnel. Perform a third extraction in the same manner.
    10.4  Separate and discard any aqueous layer remaining in the 250-mL 
separatory funnel after combining the organic extracts. Add 25 mL of 1 M 
sulfuric acid and extract the sample by shaking the funnel for 2 min. 
Transfer the aqueous layer to a 250-mL beaker. Extract with two 
additional 25-mL portions of 1 M sulfuric acid and combine the acid 
extracts in the beaker.
    10.5  Place a stirbar in the 250-mL beaker and stir the acid extract 
while carefully adding 5 mL of 0.4 M sodium tribasic phosphate. While 
monitoring with a pH meter, neutralize the extract to a pH between 6 and 
7 by dropwise addition of 5 N sodium hydroxide solution while stirring 
the solution vigorously. Approximately 25 to 30 mL of 5 N sodium 
hydroxide solution will be required and it should be added over at least 
a 2-min period. Do not allow the sample pH to exceed 8.
    10.6  Transfer the neutralized extract into a 250-mL separatory 
funnel. Add 30 mL of chloroform and shake the funnel for 2 min. Allow 
the phases to separate, and transfer the organic layer to a second 250-
mL separatory funnel.
    10.7  Extract the aqueous layer with two additional 20-mL aliquots 
of chloroform as before. Combine the extracts in the 250-mL separatory 
funnel.
    10.8  Add 20 mL of reagent water to the combined organic layers and 
shake for 30 s.
    10.9  Transfer the organic extract into a 100-mL round bottom flask. 
Add 20 mL of methanol and concentrate to 5 mL with a rotary evaporator 
at reduced pressure and 35  deg.C. An aspirator is recommended for use 
as the source of vacuum. Chill the receiver with ice. This operation 
requires approximately 10 min. Other concentration techniques may be 
used if the requirements of Section 8.2 are met.
    10.10  Using a 9-in. Pasteur pipette, transfer the extract to a 15-
mL, conical, screw-cap centrifuge tube. Rinse the flask, including the 
entire side wall, with 2-mL portions of methanol and combine with the 
original extract.
    10.11  Carefully concentrate the extract to 0.5 mL using a gentle 
stream of nitrogen while heating in a 30  deg.C water bath. Dilute to 2 
mL with methanol, reconcentrate to 1 mL, and dilute to 5 mL with acetate 
buffer. Mix the extract thoroughly. Cap the centrifuge tube and store 
refrigerated and protected from light if further processing will not be 
performed immediately. If the extract will be stored longer than two 
days, it should be transferred to a Teflon-sealed screw-cap vial. If the 
sample extract requires no further cleanup, proceed with HPLC analysis 
(Section 12). If the sample requires further cleanup, proceed to Section 
11.
    10.12  Determine the original sample volume by refilling the sample 
bottle to the mark and transferring the liquid to a 1,000-mL graduated 
cylinder. Record the sample volume to the nearest 5 mL.

                       11. Cleanup and Separation

    11.1  Cleanup procedures may not be necessary for a relatively clean 
sample matrix. If particular circumstances demand the use of a cleanup 
procedure, the analyst first must demonstrate that the requirements of 
Section 8.2 can be met using the method as revised to incorporate the 
cleanup procedure.

               12. High Performance Liquid Chromatography

    12.1  Table 1 summarizes the recommended operating conditions for 
the HPLC. Included in this table are retention times, capacity factors, 
and MDL that can be achieved under these conditions. An example of the 
separations achieved by this HPLC column is shown in Figure 1. Other 
HPLC columns, chromatographic conditions, or detectors may be used if 
the requirements of Section 8.2 are met. When the HPLC is idle, it is 
advisable to maintain a 0.1 mL/min flow through the column to prolong 
column life.
    12.2  Calibrate the system daily as described in Section 7.
    12.3  If the internal standard calibration procedure is being used, 
the internal standard must be added to the sample extract and mixed 
thoroughly immediately before injection into the instrument.

[[Page 86]]

    12.4  Inject 5 to 25 L of the sample extract or standard 
into the HPLC. If constant volume injection loops are not used, record 
the volume injected to the nearest 0.05 L, and the resulting 
peak size in area or peak height units.
    12.5  Identify the parameters in the sample by comparing the 
retention times of the peaks in the sample chromatogram with those of 
the peaks in standard chromatograms. The width of the retention time 
window used to make identifications should be based upon measurements of 
actual retention time variations of standards over the course of a day. 
Three times the standard deviation of a retention time for a compound 
can be used to calculate a suggested window size; however, the 
experience of the analyst should weigh heavily in the interpretation of 
chromatograms.
    12.6  If the response for a peak exceeds the working range of the 
system, dilute the extract with mobile phase and reanalyze.
    12.7  If the measurement of the peak response for benzidine is 
prevented by the presence of interferences, reduce the electrode 
potential to +0.6 V and reanalyze. If the benzidine peak is still 
obscured by interferences, further cleanup is required.

                            13. Calculations

    13.1  Determine the concentration of individual compounds in the 
sample.
    13.1.1  If the external standard calibration procedure is used, 
calculate the amount of material injected from the peak response using 
the calibration curve or calibration factor determined in Section 7.2.2. 
The concentration in the sample can be calculated from Equation 2.

                                                                                                                
                                                                           (A)(Vt)                              
                                        Concentration (g/  = -----------------                         
                                                    L)                     (Vi)(Vs)                             
                                                                                                                

                                                              Equation 2
where:
    A=Amount of material injected (ng).
    Vi=Volume of extract injected (L).
    Vt=Volume of total extract (L).
    Vs=Volume of water extracted (mL).

    13.1.2  If the internal standard calibration procedure is used, 
calculate the concentration in the sample using the response factor (RF) 
determined in Section 7.3.2 and Equation 3.

                                                                                                                
                                                                           (As)(Is)                             
                                        Concentration (g/  = -----------------                         
                                                    L)                  (Ais)(RF)(Vo)                           
                                                                                                                

                                                              Equation 3
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Is=Amount of internal standard added to each extract 
(g).
    Vo=Volume of water extracted (L).

    13.2  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

                         14. Method Performance

    14.1  The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the value is above zero.\1\ The MDL concentrations 
listed in Table 1 were obtained using reagent water.\10\ Similar results 
were achieved using representative wastewaters. The MDL actually 
achieved in a given analysis will vary depending on instrument 
sensitivity and matrix effects.
    14.2  This method has been tested for linearity of spike recovery 
from reagent water and has been demonstrated to be applicable over the 
concentration range from 7 x MDL to 3000 x MDL.\10\
    14.3  This method was tested by 17 laboratories using reagent water, 
drinking water, surface water, and three industrial wastewaters spiked 
at six concentrations over the range 1.0 to 70 g/L.\11\ Single 
operator precision, overall precision, and method accuracy were found to 
be directly related to the concentration of the parameter and 
essentially independent of the sample matrix. Linear equations to 
describe these relationships are presented in Table 3.

                               References

    1. 40 CFR part 136, appendix B.
    2. ``Determination of Benzidines in Industrial and Muncipal 
Wastewaters,'' EPA 600/4-82-022, National Technical Information Service, 
PB82-196320, Springfield, Virginia 22161, April 1982.
    3. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard 
Practices for Preparation of Sample Containers and for Preservation of 
Organic Constituents,'' American Society for Testing and Materials, 
Philadelphia.
    4. ``Carcinogens--Working With Carcinogens,'' Department of Health, 
Education, and Welfare, Public Health Service, Center for Disease 
Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    5. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR 
part 1910), Occupational Safety and Health Administration, OSHA 2206 
(Revised, January 1976).
    6. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent 
Recovery Data,'' American

[[Page 87]]

Laboratory, 15, 58-63 (1983). (The value 2.44 used in the equation in 
Section 8.3.3 is two times the value 1.22 derived in this report.)
    8. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard 
Practices for Sampling Water,'' American Society for Testing and 
Materials, Philadelphia.
    9. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 
(Spectrophotometric, DPD) for Chlorine Total Residual,'' Methods for 
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory, Cincinnati, Ohio 45268, March 1979.
    10. ``EPA Method Study 15, Method 605 (Benzidines),'' EPA 600/4-84-
062, National Technical Information Service, PB84-211176, Springfield, 
Virginia 22161, June 1984.
    11. ``EPA Method Validation Study 15, Method 605 (Benzidines),'' 
Report for EPA Contract 68-03-2624 (In preparation).

     Table 1--Chromatographic Conditions and Method Detection Limits    
------------------------------------------------------------------------
                                                               Method   
                                      Retention    Column     detection 
              Parameter                  time     capacity      limit   
                                        (min)      factor   (g/
                                                    (k)          L)     
------------------------------------------------------------------------
Benzidine...........................        6.1       1.44         0.08 
3,3-Dichlorobenzidine...............       12.1       3.84         0.13 
------------------------------------------------------------------------
HPLC Column conditions: Lichrosorb RP-2, 5 micron particle size, in a 25
  cm x 4.6 mm ID stainless steel column. Mobile Phase: 0.8 mL/min of 50%
  acetonitrile/50% 0.1M pH 4.7 acetate buffer. The MDL were determined  
  using an electrochemical detector operated at +0.8 V.                 


                                   Table 2--QC Acceptance Criteria--Method 605                                  
----------------------------------------------------------------------------------------------------------------
                                                                                          Range for X           
                                                              Test conc.    Limit for s  (g/  Range for
                         Parameter                           (g/  (g/       L)         P, Ps  
                                                                  L)            L)                     (percent)
----------------------------------------------------------------------------------------------------------------
Benzidine..................................................           50          18.7      9.1-61.0       D-140
3.3-Dichlorobenzidine......................................           50          23.6     18.7-50.0       5-128
----------------------------------------------------------------------------------------------------------------
s=Standard deviation of four recovery measurements, in g/L (Section 8.2.4).                            
X=Average recovery for four recovery measurements, in g/L (Section 8.2.4).                             
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).                                                 
D=Detected; result must be greater than zero.                                                                   
                                                                                                                
Note: These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits
  for recovery have been broadened to assure applicability of the limits to concentrations below those used to  
  develop Table 3.                                                                                              


                Table 3--Method Accuracy and Precision as Functions of Concentration--Method 605                
----------------------------------------------------------------------------------------------------------------
                                                                   Accuracy, as                                 
                                                                     recovery,    Single analyst      Overall   
                            Parameter                              X(g/   precision, sr   precision, S 
                                                                        L)        (g/L)  (g/L)
----------------------------------------------------------------------------------------------------------------
Benzidine.......................................................      0.70C+0.06      0.28X+0.19      0.40X+0.18
3,3-Dichlorobenzidine...........................................      0.66C+0.23      0.39X-0.05      0.38X+0.02
----------------------------------------------------------------------------------------------------------------
X=Expected recovery for one or more measurements of a sample containing a concentration of C, in g/L.  
sr=Expected single analyst standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
S=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
C=True value for the concentration, in g/L.                                                            
X=Average recovery found for measurements of samples containing a concentration of C, in g/L.          


[[Page 88]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.014


[[Page 89]]

                       Method 606--Phthalate Ester

                        1. Scope and Application

    1.1  This method covers the determination of certain phthalate 
esters. The following parameters can be determined by this method:

------------------------------------------------------------------------
                                                      STORET            
                     Parameter                         No.      CAS No. 
------------------------------------------------------------------------
Bis(2-ethylhexyl) phthalate........................    39100    117-81-7
Butyl benzyl phthalate.............................    34292     85-68-7
Di-n-butyl phthalate...............................    39110     84-74-2
Diethyl phthalate..................................    34336     84-66-2
Dimethyl phthalate.................................    34341    131-11-3
Di-n-octyl phthalate...............................    34596    117-84-0
------------------------------------------------------------------------

    1.2  This is a gas chromatographic (GC) method applicable to the 
determination of the compounds listed above in municipal and industrial 
discharges as provided under 40 CFR 136.1. When this method is used to 
analyze unfamiliar samples for any or all of the compounds above, 
compound identifications should be supported by at least one additional 
qualitative technique. This method describes analytical conditions for a 
second gas chromatographic column that can be used to confirm 
measurements made with the primary column. Method 625 provides gas 
chromatograph/mass spectrometer (GC/MS) conditions appropriate for the 
qualitative and quantitative confirmation of results for all of the 
parameters listed above, using the extract produced by this method.
    1.3  The method detection limit (MDL, defined in Section 14.1)\1\ 
for each parameter is listed in Table 1. The MDL for a specific 
wastewater may differ from those listed, depending upon the nature of 
interferences in the sample matrix.
    1.4  The sample extraction and concentration steps in this method 
are essentially the same as in Methods 608, 609, 611, and 612. Thus, a 
single sample may be extracted to measure the parameters included in the 
scope of each of these methods. When cleanup is required, the 
concentration levels must be high enough to permit selecting aliquots, 
as necessary, to apply appropriate cleanup procedures. The analyst is 
allowed the latitude, under Section 12, to select chromatographic 
conditions appropriate for the simultaneous measurement of combinations 
of these parameters.
    1.5  Any modification of this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5.
    1.6  This method is restricted to use by or under the supervision of 
analysts experienced in the use of a gas chromatograph and in the 
interpretation of gas chromatograms. Each analyst must demonstrate the 
ability to generate acceptable results with this method using the 
procedure described in Section 8.2.

                          2. Summary of Method

    2.1  A measured volume of sample, approximately 1-L, is extracted 
with methylene chloride using a separatory funnel. The methylene 
chloride extract is dried and exchanged to hexane during concentration 
to a volume of 10 mL or less. The extract is separated by gas 
chromatography and the phthalate esters are then measured with an 
electron capture detector.\2\
    2.2  Analysis for phthalates is especially complicated by their 
ubiquitous occurrence in the environment. The method provides Florisil 
and alumina column cleanup procedures to aid in the elimination of 
interferences that may be encountered.

                            3. Interferences

    3.1  Method interferences may be caused by contaminants in solvents, 
reagents, glassware, and other sample processing hardware that lead to 
discrete artifacts and/or elevated baselines in gas chromatograms. All 
of these materials must be routinely demonstrated to be free from 
interferences under the conditions of the analysis by running laboratory 
reagent blanks as described in Section 8.1.3.
    3.1.1  Glassware must be scrupulously cleaned.\3\ Clean all 
glassware as soon as possible after use by rinsing with the last solvent 
used in it. Solvent rinsing should be followed by detergent washing with 
hot water, and rinses with tap water and distilled water. The glassware 
should then be drained dry, and heated in a muffle furnace at 400  deg.C 
for 15 to 30 min. Some thermally stable materials, such as PCBs, may not 
be eliminated by this treatment. Solvent rinses with acetone and 
pesticide quality hexane may be substituted for the muffle furnace 
heating. Thorough rinsing with such solvents usually eliminates PCB 
interference. Volumetric ware should not be heated in a muffle furnace. 
After drying and cooling, glassware should be sealed and stored in a 
clean environment to prevent any accumulation of dust or other 
contaminants. Store inverted or capped with aluminum foil.
    3.1.2  The use of high purity reagents and solvents helps to 
minimize interference problems. Purification of solvents by distillation 
in all-glass systems may be required.
    3.2  Phthalate esters are contaminants in many products commonly 
found in the laboratory. It is particularly important to avoid the use 
of plastics because phthalates are commonly used as plasticizers and are 
easily extracted from plastic materials. Serious phthalate contamination 
can result at any time, if consistent quality control is not practiced. 
Great care must be experienced to prevent such contamination. Exhaustive 
cleanup of reagents and glassware may be required to eliminate 
background phthalate contamination.4,5

[[Page 90]]

    3.3  Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary 
considerably from source to source, depending upon the nature and 
diversity of the industrial complex or municipality being sampled. The 
cleanup procedures in Section 11 can be used to overcome many of these 
interferences, but unique samples may require additional cleanup 
approaches to achieve the MDL listed in Table 1.

                                4. Safety

    4.1  The toxicity or carcinogenicity of each reagent used in this 
method has not been precisely defined; however, each chemical compound 
should be treated as a potential health hazard. From this viewpoint, 
exposure to these chemicals must be reduced to the lowest possible level 
by whatever means available. The laboratory is responsible for 
maintaining a current awareness file of OSHA regulations regarding the 
safe handling of the chemicals specified in this method. A reference 
file of material data handling sheets should also be made available to 
all personnel involved in the chemical analysis. Additional references 
to laboratory safety are available and have been identified \6\-\8\ 
for the information of the analyst.

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete or composite sampling.
    5.1.1  Grab sample bottle--1-L or 1-qt, amber glass, fitted with a 
screw cap lined with Teflon. Foil may be substituted for Teflon if the 
sample is not corrosive. If amber bottles are not available, protect 
samples from light. The bottle and cap liner must be washed, rinsed with 
acetone or methylene chloride, and dried before use to minimize 
contamination.
    5.1.2  Automatic sampler (optional)--The sampler must incorporate 
glass sample containers for the collection of a minimum of 250 mL of 
sample. Sample containers must be kept refrigerated at 4  deg.C and 
protected from light during compositing. If the sampler uses a 
peristaltic pump, a minimum length of compressible silicone rubber 
tubing may be used. Before use, however, the compressible tubing should 
be thoroughly rinsed with methanol, followed by repeated rinsings with 
distilled water to minimize the potential for contamination of the 
sample. An integrating flow meter is required to collect flow 
proportional composites.
    5.2  Glassware (All specifications are suggested. Catalog numbers 
are included for illustration only).
    5.2.1  Separatory funnel--2-L, with Teflon stopcock.
    5.2.2  Drying column--Chromatographic column, approximately 400 mm 
long  x  19 mm ID, with coarse frit filter disc.
    5.2.3  Chromatographic column--300 mm long  x  10 mm ID, with Teflon 
stopcock and coarse frit filter disc at bottom (Kontes K-420540-0213 or 
equivalent).
    5.2.4  Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes 
K-570050-1025 or equivalent). Calibration must be checked at the volumes 
employed in the test. Ground glass stopper is used to prevent 
evaporation of extracts.
    5.2.5  Evaporative flask, Kuderna-Danish--500-mL (Kontes K-570001-
0500 or equivalent). Attach to concentrator tube with springs.
    5.2.6  Snyder column, Kuderna-Danish--Three-ball macro (Kontes K-
503000-0121 or equivalent).
    5.2.7  Snyder column, Kuderna-Danish--Two-ball micro (Kontes K-
569001-0219 or equivalent).
    5.2.8  Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
    5.3  Boiling chips--Approximately 10/40 mesh. Heat to 400  deg.C for 
30 min or Soxhlet extract with methylene chloride.
    5.4  Water bath--Heated, with concentric ring cover, capable of 
temperature control (2  deg.C). The bath should be used in a 
hood.
    5.5  Balance--Analytical, capable of accurately weighing 0.0001 g.
    5.6  Gas chromatograph--An analytical system complete with gas 
chromatograph suitable for on-column injection and all required 
accessories including syringes, analytical columns, gases, detector, and 
strip-chart recorder. A data system is recommended for measuring peak 
areas.
    5.6.1  Column 1--1.8 m long  x  4 mm ID glass, packed with 1.5% SP-
2250/1.95% SP-2401 Supelcoport (100/120 mesh) or equivalent. This column 
was used to develop the method performance statemelts in Section 14. 
Guidelines for the use of alternate column packings are provided in 
Section 12.1.
    5.6.2  Column 2--1.8 m long  x  4 mm ID glass, packed with 3% OV-1 
on Supelcoport (100/120 mesh) or equivalent.
    5.6.3  Detector--Electron capture detector. This detector has proven 
effective in the analysis of wastewaters for the parameters listed in 
the scope (Section 1.1), and was used to develop the method performance 
statements in Section 14. Guidelines for the use of alternate detectors 
are provided in Section 12.1.

                               6. Reagents

    6.1  Reagent water--Reagent water is defined as a water in which an 
interferent is not observed at the MDL of the parameters of interest.
    6.2  Acetone, hexane, isooctane, methylene chloride, methanol--
Pesticide quality or equivalent.
    6.3  Ethyl ether--nanograde, redistilled in glass if necessary.
    6.3.1  Ethyl ether must be shown to be free of peroxides before it 
is used as indicated by

[[Page 91]]

EM Laboratories Quant test strips. (Available from Scientific Products 
Co., Cat. No. P1126-8, and other suppliers.)
    6.3.2  Procedures recommended for removal of peroxides are provided 
with the test strips. After cleanup, 20 mL of ethyl alcohol preservative 
must be added to each liter of ether.
    6.4  Sodium sulfate--(ACS) Granular, anhydrous. Several levels of 
purification may be required in order to reduce background phthalate 
levels to an acceptable level: 1) Heat 4 h at 400  deg.C in a shallow 
tray, 2) Heat 16 h at 450 to 500  deg.C in a shallow tray, 3) Soxhlet 
extract with methylene chloride for 48 h.
    6.5  Florisil--PR grade (60/100 mesh). Purchase activated at 1250 
deg.F and store in the dark in glass containers with ground glass 
stoppers or foil-lined screw caps. To prepare for use, place 100 g of 
Florisil into a 500-mL beaker and heat for approximately 16 h at 40 
deg.C. After heating transfer to a 500-mL reagent bottle. Tightly seal 
and cool to room temperature. When cool add 3 mL of reagent water. Mix 
thoroughly by shaking or rolling for 10 min and let it stand for at 
least 2 h. Keep the bottle sealed tightly.
    6.6  Alumina--Neutral activity Super I, W200 series (ICN Life 
Sciences Group, No. 404583). To prepare for use, place 100 g of alumina 
into a 500-mL beaker and heat for approximately 16 h at 400  deg.C. 
After heating transfer to a 500-mL reagent bottle. Tightly seal and cool 
to room temperature. When cool add 3 mL of reagent water. Mix thoroughly 
by shaking or rolling for 10 min and let it stand for at least 2 h. Keep 
the bottle sealed tightly.
    6.7  Stock standard solutions (1.00 g/L)--Stock 
standard solutions can be prepared from pure standard materials or 
purchased as certified solutions.
    6.7.1  Prepare stock standard solutions by accurately weighing about 
0.0100 g of pure material. Dissolve the material in isooctane and dilute 
to volume in a 10-mL volumetric flask. Larger volumes can be used at the 
convenience of the analyst. When compound purity is assayed to be 96% or 
greater, the weight can be used without correction to calculate the 
concentration of the stock standard. Commercially prepared stock 
standards can be used at any concentration if they are certified by the 
manufacturer or by an independent source.
    6.7.2  Transfer the stock standard solutions into Teflon-sealed 
screw-cap bottles. Store at 4  deg.C and protect from light. Stock 
standard solutions should be checked frequently for signs of degradation 
or evaporation, especially just prior to preparing calibration standards 
from them.
    6.7.3  Stock standard solutions must be replaced after six months, 
or sooner if comparison with check standards indicates a problem.
    6.8  Quality control check sample concentrate--See Section 8.2.1.

                             7. Calibration

    7.1  Establish gas chromatograph operating conditions equivalent to 
those given in Table 1. The gas chromatographic system can be calibrated 
using the external standard technique (Section 7.2) or the internal 
standard technique (Section 7.3).
    7.2  External standard calibration procedure:
    7.2.1  Prepared calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask and diluting to volume 
with isooctane. One of the external standards should be at a 
concentration near, but above, the MDL (Table 1) and the other 
concentrations should correspond to the expected range of concentrations 
found in real samples or should define the working range of the 
detector.
    7.2.2  Using injections of 2 to 5 L, analyze each 
calibration standard according to Section 12 and tabulate peak height or 
area responses against the mass injected. The results can be used to 
prepare a calibration curve for each compound. Alternatively, if the 
ratio of response to amount injected (calibration factor) is a constant 
over the working range (< 10% relative standard deviation, RSD), 
linearity through the origin can be assumed and the average ratio or 
calibration factor can be used in place of a calibration curve.
    7.3  Internal standard calibration procedure--To use this approach, 
the analyst must select one or more internal standards that are similar 
in analytical behavior to the compounds of interest. The analyst must 
further demonstrate that the measurement of the internal standard is not 
affected by method or matrix interferences. Because of these 
limitations, no internal standard can be suggested that is applicable to 
all samples.
    7.3.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flash. To each calibration 
standard, add a known constant amount of one or more internal standards, 
and dilute to volume with isooctane. One of the standards should be at a 
concentraton near, but above, the MDL and the other concentrations 
should correspond to the expected range of concentrations found in real 
samples or should define the working range of the detector.
    7.3.2  Using injections of 2 to 5 L, analyze each 
calibration standard according to Section 12 and tabulate peak height or 
area responses against concentration for each compound and internal 
standard. Calculate

[[Page 92]]

response factors (RF) for each compound using Equation 1.

                                                                                                                
                                                                   RF=      (As)(Cis)    (Ais)(Cs)              
                                                                                                                

                                                              Equation 1
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Cis=Concentration of the internal standard (g/L).
    Cs=Concentration of the parameter to be measured (g/
L).
    If the RF value over the working range is a constant (< 10% RSD), 
the RF can be assumed to be invariant and the average RF can be used for 
calculations. Alternatively, the results can be used to plot a 
calibration curve of response ratios, As/Ais, vs. RF.
    7.4  The working calibration curve, calibration factor, or RF must 
be verified on each working day by the measurement of one or more 
calibration standards. If the response for any parameter varies from the 
predicted response by more than 15%, a new calibration curve 
must be prepared for that compound.
    7.5  Before using any cleanup procedure, the analyst must process a 
series of calibration standards through the procedure to validate 
elution patterns and the absence of interferences from the reagents.

                           8. Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality control program. The minimum requirements of this program 
consist of an initial demonstration of laboratory capability and an 
ongoing analysis of spiked samples to evaluate and document data 
quality. The laboratory must maintain records to document the quality of 
data that is generated. Ongoing data quality checks are compared with 
established performance criteria to determine if the results of analyses 
meet the performance characteristics of the method. When results of 
sample spikes indicate atypical method performance, a quality control 
check standard must be analyzed to confirm that the measurements were 
performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occurring in 
chromatography, the analyst is permitted certain options (detailed in 
Sections 10.4, 11.1, and 12.1) to improve the separations or lower the 
cost of measurements. Each time such a modification is made to the 
method, the analyst is required to repeat the procedure in Section 8.2.
    8.1.3  Before processing any samples, the analyst must analyze a 
reagent water blank to demonstrate that interferences from the 
analytical system and glassware are under control. Each time a set of 
samples is extracted or reagents are changed, a reagent water blank must 
be processed as a safeguard against laboratory contamination.
    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 10% of all samples to monitor and evaluate laboratory data 
quality. This procedure is described in Section 8.3.
    8.1.5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 10% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.5.
    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality contrml (QC) check sample concentrate is required 
containing each parameter of interest at the following concentrations in 
acetone: butyl benzyl phthalate, 10 g/mL; bis(2-ethylhexyl) 
phthalate, 50 g/mL; di-n-octyl phthalate, 50 g/mL; any 
other phthlate, 25 g/mL. The QC check sample concentrate must 
be obtained from the U.S. Environmental Protection Agancy, Environmental 
Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If 
not available from that source, the QC check sample concentrate must be 
obtained from another external source. If not available from either 
source above, the QC check sample concentrate must be prepared by the 
laboratory using stock standards prepared independently from those used 
for calibration.
    8.2.2  Using a pipet, prepare QC check samples at the test 
concentrations shown in Table 2 by adding 1.00 mL of QC check sample 
concentrate to each of four 1-L aliquots of reagent water.
    8.2.3  Analyze the well-mixed QC check samples according to the 
method beginning in Section 10.
    8.2.4  Calculate the average recovery (X) in g/L, and the 
standard deviation of the recovery (s) in g/L, for each 
parameter using the four results.
    8.2.5  For each parameter compare s and X with the corresponding 
acceptance criteria for precision and accuracy, respectively, found in 
Table 2. If s and X for all parameters of interest meet the acceptance 
criteria, the system performance is acceptable and analysis of actual 
samples can begin. If

[[Page 93]]

any individual s exceeds the precision limit or any individual X falls 
outside the range for accuracy, the system performance is unacceptable 
for that parameter. Locate and correct the source of the problem and 
repeat the test for all parameters of interest beginning with Section 
8.2.2.
    8.3  The laboratory must, on an ongoing basis, spike at least 10% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing one to ten samples per month, at least one 
spiked sample per month is required.
    8.3.1  The concentration of the spike in the sample should be 
determined as follows:
    8.3.1.1  If, as in compliance monitoring, the concentration of a 
specific parameter in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of a specific parameter in the sample 
is not being checked against a limit specific to that parameter, the 
spike should be at the test concentration in Section 8.2.2 or 1 to 5 
times higher than the background concentration determined in Section 
8.3.2, whichever concentration would be larger.
    8.3.1.3  If it is impractical to determine background levels before 
spiking (e.g., maximum holding times will be exceeded), the spike 
concentration should be (1) the regulatory concentration limit, if any; 
or, if none (2) the larger of either 5 times higher than the expected 
background concentration or the test concentration in Section 8.2.2.
    8.3.2  Analyze one sample aliquot to determine the background 
concentration (B) of each parameter. If necessary, prepare a new QC 
check sample concentrate (Section 8.2.1) appropriate for the background 
concentrations in the sample. Spike a second sample aliquot with 1.0 mL 
of the QC check sample concentrate and analyze it to determine the 
concentration after spiking (A) of each parameter. Calculate each 
percent recovery (P) as 100(A-B)%/T, where T is the known true value of 
the spike.
    8.3.3  Compare the percent recovery (P) for each parameter with the 
corresponding QC acceptance criteria found in Table 2. These acceptance 
criteria were calculated to include an allowance for error in 
measurement of both the background and spike concentrations, assuming a 
spike to background ratio of 5:1. This error will be accounted for to 
the extent that the analyst's spike to background ratio approaches 
5:1.\9\ If spiking was performed at a concentration lower than the test 
concentration in Section 8.2.2, the analyst must use either the QC 
acceptance criteria in Table 2, or optional QC acceptance criteria 
calculated for the specific spike concentration. To calculate optional 
acceptance criteria for the recovery of a parameter: (1) Calculate 
accuracy (X') using the equation in Table 3, substituting the spike 
concentration (T) for C; (2) calculate overall precision (S') using the 
equation in Table 3, substituting X' for X; (3) calculate the range for 
recovery at the spike concentration as (100 X'/T)2.44(100 
S'/T)%.\9\
    8.3.4  If any individual P falls outside the designated range for 
recovery, that parameter has failed the acceptance criteria. A check 
standard containing each parameter that failed the criteria must be 
analyzed as described in Section 8.4.
    8.4  If any parameter fails the acceptance criteria for recovery in 
Section 8.3, a QC check standard containing each parameter that failed 
must be prepared and analyzed.
    Note: The frequency for the required analysis of a QC check standard 
will depend upon the number of parameters being simultaneously tested, 
the complexity of the sample matrix, and the performance of the 
laboratory.
      8.4.1  Prepare the QC check standard by adding 1.0 mL of QC check 
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The 
QC check standard needs only to contain the parameters that failed 
criteria in the test in Section 8.3.
      8.4.2  Analyze the QC check standard to determine the 
concentration measured (A) of each parameter. Calculate each percent 
recovery (Ps) as 100 (A/T)%, where T is the true value of the 
standard concentration.
      8.4.3  Compare the percent recovery (Ps) for each parameter 
with the corresponding QC acceptance criteria found in Table 2. Only 
parameters that failed the test in Section 8.3 need to be compared with 
these criteria. If the recovery of any such parameter falls outside the 
designated range, the laboratory performance for that parameter is 
judged to be out of control, and the problem must be immediately 
identified and corrected. The analytical result for that parameter in 
the unspiked sample is suspect and may not be reported for regulatory 
compliance purposes.
      8.5  As part of the QC program for the laboratory, method accuracy 
for wastewater samples must be assessed and records must be maintained. 
After the analysis of five spiked wastewater samples as in Section 8.3, 
calculate the average percent recovery (P) and the standard deviation of 
the percent recovery (sp). Express the accuracy assessment as a 
percent recovery interval from P-2sp to P+2sp. If P=90% and 
sp=10%, for example, the accuracy interval is expressed as 70-110%. 
Update the accuracy assessment for each parameter on a regular basis 
(e.g. after each five to ten new accuracy measurements).
      8.6  It is recommended that the laboratory adopt additional 
quality assurance practices for use with this method. The specific 
practices that are most productive depend upon the needs of the 
laboratory and

[[Page 94]]

the nature of the samples. Field duplicates may be analyzed to assess 
the precision of the environmental measurements. When doubt exists over 
the identification of a peak on the chromatogram, confirmatory 
techniques such as gas chromatography with a dissimilar column, specific 
element detector, or mass spectrometer must be used. Whenever possible, 
the laboratory should analyze standard reference materials and 
participate in relevant performance evaluation studies.

            9. Sample Collection, Preservation, and Handling

    9.1  Grab samples must be collected in glass containers. 
Conventional sampling practices\10\ should be followed, except that the 
bottle must not be prerinsed with sample before collection. Composite 
samples should be collected in refrigerated glass containers in 
accordance with the requirements of the program. Automatic sampling 
equipment must be as free as possible of Tygon tubing and other 
potential sources of contamination.
    9.2  All samples must be iced or refrigerated at 4  deg.C from the 
time of collection until extraction.
    9.3  All samples must be extracted within 7 days of collection and 
completely analyzed within 40 days of extraction.\2\

                          10. Sample Extraction

    10.1  Mark the water meniscus on the side of the sample bottle for 
later determination of sample volume. Pour the entire sample into a 2-L 
separatory funnel.
    10.2  Add 60 mL of methylene chloride to the sample bottle, seal, 
and shake 30 s to rinse the inner surface. Transfer the solvent to the 
separatory funnel and extract the sample by shaking the funnel for 2 
min. with periodic venting to release excess pressure. Allow the organic 
layer to separate from the water phase for a minimum of 10 min. If the 
emulsion interface between layers is more than one-third the volume of 
the solvent layer, the analyst must employ mechanical techniques to 
complete the phrase separation. The optimum technique depends upon the 
sample, but may include stirring, filtration of the emulsion through 
glass wool, centrifugation, or other physical methods. Collect the 
methylene chloride extract in a 250-mL Erlenmeyer flask.
    10.3  Add a second 60-mL volume of methylene chloride to the sample 
bottle and repeat the extraction procedure a second time, combining the 
extracts in the Erlenmeyer flask. Perform a third extraction in the same 
manner.
    10.4  Assemble a Kuderna-Danish (K-D) concentrator by attaching a 
10-mL concentrator tube to a 500-mL evaporative flask. Other 
concentrator devices or techniques may be used in place of the K-D 
concentrator if the requirements of Section 8.2 are met.
    10.5  Pour the combined extract through a solvent-rinsed drying 
column containing about 10 cm of anhydrous sodium sulfate, and collect 
the extract in the K-D concentrator. Rinse the Erlenmeyer flask and 
column with 20 to 30 mL of methylene chloride to complete the 
quantitative transfer.
    10.6  Add one or two clean boiling chips to the evaporative flask 
and attach a three-ball Snyder column. Prewet the Snyder column by 
adding about 1 mL of methylene chloride to the top. Place the K-D 
apparatus on a hot water bath (60 to 65  deg.C) so that the concentrator 
tube is partially immersed in the hot water, and the entire lower 
rounded surface of the flask is bathed with hot vapor. Adjust the 
vertical position of the apparatus and the water temperature as required 
to complete the concentration in 15 to 20 min. At the proper rate of 
distillation the balls of the column will actively chatter but the 
chambers will not flood with condensed solvent. When the apparent volume 
of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain 
and cool for at least 10 min.
    10.7  Increase the temperature of the hot water bath to about 80 
deg.C. Momentarily remove the Snyder column, add 50 mL of hexane and a 
new boiling chip, and reattach the Snyder column. Concentrate the 
extract as in Section 10.6, except use hexane to prewet the column. The 
elapsed time of concentration should be 5 to 10 min.
    10.8  Remove the Snyder column and rinse the flask and its lower 
joint into the concentrator tube with 1 to 2 mL of hexane. A 5-mL 
syringe is recommended for this operation. Adjust the extract volume to 
10 mL. Stopper the concentrator tube and store refrigerated if further 
processing will not be performed immediately. If the extract will be 
stored longer than two days, it should be transferred to a Teflon-sealed 
screw-cap vial. If the sample extract requires no further cleanup, 
proceed with gas chromatographic analysis (Section 12). If the sample 
requires further cleanup, proceed to Section 11.
    10.9  Determine the original sample volume by refilling the sample 
bottle to the mark and transferring the liquid to a 1000-mL graduated 
cylinder. Record the sample volume to the nearest 5 mL.

                       11. Cleanup and Separation

    11.  Cleanup procedures may not be necessary for a relatively clean 
sample matrix. If particular circumstances demand the use of a cleanup 
procedure, the analyst may use either procedure below or any other 
appropriate procedure. However, the analyst first must demonstrate that 
the requirements of Section 8.2 can be met using the method as revised 
to incorporate the cleanup procedure.

[[Page 95]]

    11.2  If the entire extract is to be cleaned up by one of the 
following procedures, it must be concentrated to 2.0 mL. To the 
concentrator tube in Section 10.8, add a clean boiling chip and attach a 
two-ball micro-Snyder column. Prewet the column by adding about 0.5 mL 
of hexane to the top. Place the micro-K-D apparatus on a hot water bath 
(80  deg.C) so that the concentrator tube is partially immersed in the 
hot water. Adjust the vertical position of the apparatus and the water 
temperature as required to complete the concentration in 5 to 10 min. At 
the proper rate of distillation the balls of the column will actively 
chatter but the chambers will not flood. When the apparent volume of 
liquid reaches about 0.5 mL, remove the K-D apparatus and allow it to 
drain and cool for at least 10 min. Remove the micro-Snyder column and 
rinse its lower joint into the concentrator tube with 0.2 mL of hexane. 
Adjust the final volume to 2.0 mL and proceed with one of the following 
cleanup procedures.
    11.3  Florisil column cleanup for phthalate esters:
    11.3.1  Place 10 g of Florisil into a chromatographic column. Tap 
the column to settle the Florisil and add 1 cm of anhydrous sodium 
sulfate to the top.
    11.3.2  Preelute the column with 40 mL of hexane. The rate for all 
elutions should be about 2 mL/min. Discard the eluate and just prior to 
exposure of the sodium sulfate layer to the air, quantitatively transfer 
the 2-mL sample extract onto the column using an additional 2 mL of 
hexane to complete the transfer. Just prior to exposure of the sodium 
sulfate layer to the air, add 40 mL of hexane and continue the elution 
of the column. Discard this hexane eluate.
    11.3.3  Next, elute the column with 100 mL of 20% ethyl ether in 
hexane (V/V) into a 500-mL K-D flask equipped with a 10-mL concentrator 
tube. Concentrate the collected fraction as in Section 10.6. No solvent 
exchange is necessary. Adjust the volume of the cleaned up extract to 10 
mL in the concentrator tube and analyze by gas chromatography (Section 
12).
    11.4  Alumina column cleanup for phthalate esters:
    11.4.1  Place 10 g of alumina into a chromatographic column. Tap the 
column to settle the alumina and add 1 cm of anhydrous sodium sulfate to 
the top.
    11.4.2  Preelute the column with 40 mL of hexane. The rate for all 
elutions should be about 2 mL/min. Discard the eluate and just prior to 
exposure of the sodium sulfate layer to the air, quantitatively transfer 
the 2-mL sample extract onto the column using an additional 2 mL of 
hexane to complete the transfer. Just prior to exposure of the sodium 
sulfate layer to the air, add 35 mL of hexane and continue the elution 
of the column. Discard this hexane eluate.
    11.4.3  Next, elute the column with 140 mL of 20% ethyl ether in 
hexane (V/V) into a 500-mL K-D flask equipped with a 10-mL concentrator 
type. Concentrate the collected fraction as in Section 10.6. No solvent 
exchange is necessary. Adjust the volume of the cleaned up extract to 10 
mL in the concentrator tube and analyze by gas chromatography (Section 
12).

                         12. Gas Chromatography

    12.1  Table 1 summarizes the recommended operating conditions for 
the gas chromatograph. Included in this table are retention times and 
MDL that can be achieved under these conditions. Examples of the 
separations achieved by Column 1 are shown in Figures 1 and 2. Other 
packed or capillary (open-tubular) columns, chromatographic conditions, 
or detectors may be used if the requirements of Section 8.2 are met.
    12.2  Calibrate the system daily as described in Section 7.
    12.3  If the internal standard calibration procedure is being used, 
the internal staldard must be added to the sample extract and mixed 
thoroughly immediately before injection into the gas chromatograph.
    12.4  Inject 2 to 5 L of the sample extract or standard 
into the gas-chromatograph using the solvent-flush technique.\11\ 
Smaller (1.0 L) volumes may be injected if automatic devices 
are employed. Record the volume injected to the nearest 0.05 L, 
and the resulting peak size in area or peak height units.
    12.5  Identify the parameters in the sample by comparing the 
retention times of the peaks in the sample chromatogram with those of 
the peaks in standard chromatograms. The width of the retention time 
window used to make identifications should be based upon measurements of 
actual retention time variations of standards over the course of a day. 
Three times the standard deviation of a retention time for a compound 
can be used to calculate a suggested window size; however, the 
experience of the analyst should weigh heavily in the interpretation of 
chromatograms.
    12.6  If the response for a peak exceeds the working range of the 
system, dilute the extract and reanalyze.
    12.7  If the measurement of the peak response is prevented by the 
presence of interferences, further cleanup is required.

                            13. Calculations

    13.1  Determine the concentration of individual compounds in the 
sample.
    13.1.1  If the external standard calibration procedure is used, 
calculate the amount of material injected from the peak response using 
the calibration curve or calibration

[[Page 96]]

factor determined in Section 7.2.2. The concentration in the sample can 
be calculated from Equation 2.

                                                                                                                
                                                                           (A)(Vt)                              
                                        Concentration (g/  = -----------------                         
                                                    L)                     (Vi)(Vs)                             
                                                                                                                

                                                              Equation 2
where:
    A=Amount of material injected (ng).
    Vi=Volume of extract injected (L).
    Vt=Volume of total extract (L).
    Vs=Volume of water extracted (mL).

    13.1.2  If the internal standard calibration procedure is used, 
calculate the concentration in the sample using the response factor (RF) 
determined in Section 7.3.2 and Equation 3.

                                                                                                                
                                                                           (As)(Is)                             
                                        Concentration (g/  = -----------------                         
                                                    L)                  (Ais)(RF)(Vo)                           
                                                                                                                

                                                              Equation 3
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Is=Amount of internal standard added to each extract 
(g).
    Vo=Volume of water extracted (L).
    13.2  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

                         14. Method Performance

    14.1  The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the value is above zero.\1\ The MDL concentrations 
listed in Table 1 were obtained using reagent water.\12\ Similar results 
were achieved using representative wastewaters. The MDL actually 
achieved in a given analysis will vary depending on instrument 
sensitivity and matrix effects.
    14.2  This method has been tested for linearity of spike recovery 
from reagent water and has been demonstrated to be applicable over the 
concentration range from 5  x  MDL to 1000  x  MDL with the following 
exceptions: dimethyl and diethyl phthalate recoveries at 1000  x  MDL 
were low (70%); bis-2-ethylhexyl and di-n-octyl phthalate recoveries at 
5  x  MDL were low (60%).\12\
    14.3  This method was tested by 16 laboratories using reagent water, 
drinking water, surface water, and three industrial wastewaters spiked 
at six concentrations over the range 0.7 to 106 g/L.\13\ Single 
operator precision, overall precision, and method accuracy were found to 
be directly related to the concentration of the parameter and 
essentially independent of the sample matrix. Linear equations to 
describe these relationships are presented in Table 3.

                               References

    1. 40 CFR part 136, appendix B.
    2. ``Determination of Phthalates in Industrial and Muncipal 
Wastewaters,'' EPA 600/4-81-063, National Technical Information Service, 
PB81-232167, Springfield, Virginia 22161, July 1981.
    3. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard 
Practices for Preparation of Sample Containers and for Preservation of 
Organic Constituents,'' American Society for Testing and Materials, 
Philadelphia.
    4. Giam, C.S., Chan, H.S., and Nef, G.S. ``Sensitive Method for 
Determination of Phthalate Ester Plasticizers in Open-Ocean Biota 
Samples,'' Analytical Chemistry, 47, 2225 (1975).
    5. Giam, C.S., and Chan, H.S. ``Control of Blanks in the Analysis of 
Phthalates in Air and Ocean Biota Samples,'' U.S. National Bureau of 
Standards, Special Publication 442, pp. 701-708, 1976.
    6. ``Carcinogens--Working with Carcinogens,'' Department of Health, 
Education, and Welfare, Public Health Service, Center for Disease 
Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    7. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR 
part 1910), Occupational Safety and Health Administration, OSHA 2206 
(Revised, January 1976).
    8. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    9. Provost L.P., and Elder, R.S. ``Interpretation of Percent 
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44 
used in the equation in Section 8.3.3 is two times the value 1.22 
derived in this report.)
    10. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard 
Practices for Sampling Water,'' American Society for Testing and 
Materials, Philadelphia.
    11. Burke, J.A. ``Gas Chromatography for Pesticide Residue Analysis; 
Some Practical Aspects,'' Journal of the Association of Official 
Analytical Chemists, 48, 1037 (1965).
    12. ``Method Detection Limit and Analytical Curve Studies, EPA 
Methods 606, 607, and 608,'' Special letter report for EPA Contract 68-
03-2606, U.S. Environmental Protection Agency, Environmental Monitoring 
and Support Laboratory, Cincinnati, Ohio 45268, June 1980.
    13. ``EPA Method Study 16 Method 606 (Phthalate Esters),'' EPA 600/
4-84-056, National Technical Information Service, PB84-211275, 
Springfield, Virginia 22161, June 1984.

[[Page 97]]



     Table 1--Chromatographic Conditions and Method Detection Limits    
------------------------------------------------------------------------
                                   Retention time (min)        Method   
                               ----------------------------   detection 
           Parameter                                            limit   
                                  Column 1      Column 2    (g/
                                                                 L)     
------------------------------------------------------------------------
Dimethyl phthalate............          2.03          0.95          0.29
Diethyl phthalate.............          2.82          1.27          0.49
Di-n-butyl phthalate..........          8.65          3.50          0.36
Butyl benzyl phthalate........        a 6.94        a 5.11          0.34
Bis(2-ethylhexyl) phthalate...        a 8.92       a 10.5           2.0 
Di-n-octyl phthalate..........       a 16.2        a 18.0           3.0 
------------------------------------------------------------------------
Column 1 conditions: Supelcoport (100/120 mesh) coated with 1.5% SP-2250/
  1.95% SP-2401 packed in a 1.8 m long  x  4 mm ID glass column with 5% 
  methane/95% argon carrier gas at 60 mL/min flow rate. Column          
  temperature held isothermal at 180C, except where otherwise indicated.
Column 2 conditions: Supelcoport (100/120 mesh) coated with 3% OV-1     
  packed in a 1.8 m long  x  4 mm ID glass column with 5% methane/95%   
  argon carrier gas at 60 mL/min flow rate. Column temperature held     
  isothermal at 200 C, except where otherwise indicated.                
                                                                        
a 220 C column temperature.                                             


                                   Table 2--QC Acceptance Criteria--Method 606                                  
----------------------------------------------------------------------------------------------------------------
                                                                                          Range for X           
                                                              Test conc.    Limit for s  (g/  Range for
                         Parameter                           (g/  (g/       L)         P, Ps  
                                                                  L)            L)                     (percent)
----------------------------------------------------------------------------------------------------------------
Bis(2-ethylhexyl) phthalate................................           50          38.4      1.2-55.9       D-158
Butyl benzyl phthalate.....................................           10           4.2      5.7-11.0      30-136
Di-n-butyl phthalate.......................................           25           8.9     10.3-29.6      23-136
Diethyl phthalate..........................................           25           9.0      1.9-33.4       D-149
Dimethyl phathalate........................................           25           9.5      1.3-35.5       D-156
Di-n-octyl phthalate.......................................           50          13.4        D-50.0       D-114
----------------------------------------------------------------------------------------------------------------
s=Standard deviation of four recovery measurements, in g/L (Section 8.2.4).                            
X=Average recovery for four recovery measurements, in g/L (Section 8.2.4).                             
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).                                                 
D=Detected; result must be greater than zero.                                                                   
                                                                                                                
Note: These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits
  for recovery have been broadened to assure applicability of the limits to concentrations below those used to  
  develop Table 3.                                                                                              


                Table 3--Method Accuracy and Precision as Functions of Concentration--Method 606                
----------------------------------------------------------------------------------------------------------------
                                                                   Accuracy, as   Single analyst      Overall   
                            Parameter                              recovery, X'   precision, sr'   precision, S'
                                                                  (g/L)  (g/L)  (g/L)
----------------------------------------------------------------------------------------------------------------
Bis(2-ethylhexyl) phthalate.....................................      0.53C+2.02      0.80X-2.54      0.73X-0.17
Butyl benzyl phthalate..........................................      0.82C+0.13      0.26X+0.04      0.25X+0.07
Di-n-butyl phthalate............................................      0.79C+0.17      0.23X+0.20      0.29X+0.06
Diethyl phthalate...............................................      0.70C+0.13      0.27X+0.05      0.45X+0.11
Dimethyl phthalate..............................................      0.73C+0.17      0.26X+0.14      0.44X+0.31
Di-n-octyl phthalate............................................      0.35C-0.71      0.38X+0.71      0.62X+0.34
----------------------------------------------------------------------------------------------------------------
X'=Expected recovery for one or more measurements of a sample containing a concentration of C, in g/L. 
sr'=Expected single analyst standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
S'=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
C=True value for the concentration, in g/L.                                                            
X=Average recovery found for measurements of samples containing a concentration of C, in g/L.          


[[Page 98]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.015

  
  
  
  
  
  
  

[[Page 99]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.016


  
  
  
  
  
  
  

[[Page 100]]

                        Method 607--Nitrosamines

                        1. Scope and Application

    1.1  This method covers the determination of certain nitrosamines. 
The following parameters can be determined by this method:

------------------------------------------------------------------------
                   Parameter                     Storet No.    CAS No.  
------------------------------------------------------------------------
N-Nitrosodimethylamine........................        34438      62-75-9
N-Nitrosodiphenylamine........................        34433      86-30-6
N-Nitrosodi-n-propylamine.....................        34428     621-64-7
------------------------------------------------------------------------

    1.2  This is a gas chromatographic (GC) method applicable to the 
determination of the parameters listed above in municipal and industrial 
discharges as provided under 40 CFR 136.1. When this method is used to 
analyze unfamiliar samples for any or all of the compmunds above, 
compound identifications should be supported by at least one additional 
qualitative technique. This method describes analytical conditimns for a 
second gas chromatographic column that can be used to confirm 
measurements made with the primary column. Method 625 provides gas 
chromatograph/mass spectrometer (GC/MS) conditions appropriate for the 
qualitative and quantitative confirmation of results for N-nitrosodi-n-
propylamine. In order to confirm the presence of N-nitrosodiphenylamine, 
the cleanup procedure specified in Section 11.3 or 11.4 must be used. In 
order to confirm the presence of N-nitrosodimethylamine by GC/MS, Column 
1 of this method must be substituted for the column recommended in 
Method 625. Confirmation of these parameters using GC-high resolution 
mass spectrometry or a Thermal Energy Analyzer is also recommended. 
1,2
    1.3  The method detection limit (MDL, defined in Section 14.1)3 
for each parameter is listed in Table 1. The MDL for a specific 
wastewater may differ from those listed, depending upon the nature of 
interferences in the sample matrix.
    1.4  Any modification of this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5.
    1.5  This method is restricted to use by or under the supervision of 
analysts experienced in the use of a gas chromatograph and in the 
interpretation of gas chromatograms. Each analyst must demonstrate the 
ability to generate acceptable results with this method using the 
procedure described in Section 8.2.

                          2. Summary of Method

    2.1  A measured volume of sample, approximately 1-L, is extracted 
with methylene chloride using a separatory funnel. The methylene 
chloride extract is washed with dilute hydrochloric acid to remove free 
amines, dried, and concentrated to a volume of 10 mL or less. After the 
extract has been exchanged to methanol, it is separated by gas 
chromatography and the parameters are then measured with a nitrogen-
phosphorus detector.4
    2.2  The method provides Florisil and alumina column cleanup 
procedures to separate diphenylamine from the nitrosamines and to aid in 
the elimination of interferences that may be encountered.

                            3. Interferences

    3.1  Method interferences may be caused by contaminants in solvents, 
reagents, glassware, and other sample processing hardware that lead to 
discrete artifacts and/or elevated baselines in gas chromatograms. All 
of these materials must be routinely demonstrated to be free from 
interferences under the conditions of the analysis by running laboratory 
reagent blanks as described in Section 8.1.3.
    3.1.1  Glassware must be scrupulously cleaned.5 Clean all 
glassware as soon as possible after use by rinsing with the last solvent 
used in it. Solvent rinsing should be followed by detergent washing with 
hot water, and rinses with tap water and distilled water. The glassware 
should then be drained dry, and heated in a muffle furnace at 400  deg.C 
for 15 to 30 min. Solvent rinses with acetone and pesticide quality 
hexane may be substituted for the muffle furnace heating. Volumetric 
ware should not be heated in a muffle furnace. After drying and cooling, 
glassware should be sealed and stored in a clean environment to prevent 
any accumulation of dust or other contaminants. Store inverted or capped 
with aluminum foil.
    3.1.2  The use of high purity reagents and solvents helps to 
minimize interference problems. Purification of solvents by distillation 
in all-glass systems may be required.
    3.2  Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary 
considerably from source to source, depending upon the nature and 
diversity of the industrial complex or municipality being sampled. The 
cleanup procedures in Section 11 can be used to overcome many of these 
interferences, but unique samples may require additional cleanup 
approaches to achieve the MDL listed in Table 1.
    3.3  N-Nitrosodiphenylamine is reported6-9 to undergo 
transnitrosation reactions. Care must be exercised in the heating or 
concentrating of solutions containing this compound in the presence of 
reactive amines.
    3.4  The sensitive and selective Thermal Energy Analyzer and the 
reductive Hall detector may be used in place of the nitrogen-phosphorus 
detector when interferences are encountered. The Thermal Energy Analyzer 
offers the highest selectivity of the non-MS detectors.

[[Page 101]]

                                4. Safety

    4.1  The toxicity or carcinogenicity of each reagent used in this 
method has not been precisely defined; however, each chemical compound 
should be treated as a potential health hazard. From this viewpoint, 
exposure to these chemicals must be reduced to the lowest possible level 
by whatever means available. The laboratory is responsible for 
maintaining a current awareness file of OSHA regulations regarding the 
safe handling of the chemicals specified in this method. A reference 
file of material data handling sheets should also be made available to 
all personnel involved in the chemical analysis. Additional references 
to laboratory safety are available and have been identified 10-12 
for the information of the analyst.
    4.2  These nitrosamines are known carcinogens 13-17, therefore, 
utmost care must be exercised in the handling of these materials. 
Nitrosamine reference standards and standard solutions should be handled 
and prepared in a ventilated glove box within a properly ventilated 
room.

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete or composite sampling.
    5.1.1  Grab sample bottle--1-L or 1-qt, amber glass, fitted with a 
screw cap lined with Teflon. Foil may be substituted for Teflon if the 
sample is not corrosive. If amber bottles are not available, protect 
samples from light. The bottle and cap liner must be washed, rinsed with 
acetone or methylene chloride, and dried before use to minimize 
contamination.
    5.1.2  Automatic sampler (optional)--The sampler must incorporate 
glass sample containers for the collection of a minimum of 250 mL of 
sample. Sample containers must be kept refrigerated at 4  deg.C and 
protected from light during compositing. If the sampler uses a 
peristaltic pump, a minimum length of compressible silicone rubber 
tubing may be used. Before use, however, the compressible tubing should 
be thoroughly rinsed with methanol, followed by repeated rinsings with 
distilled water to minimize the potential for contamination of the 
sample. An integrating flowmeter is required to collect flow 
proportional composites.
    5.2  Glassware (All specifications are suggested. Catalog numbers 
are included for illustration only.):
    5.2.1  Separatory funnels--2-L and 250-mL, with Teflon stopcock.
    5.2.2  Drying column--Chromatographic column, approximately 400 mm 
long  x  19 mm ID, with coarse frit filter disc.
    5.2.3  Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes 
K-570050-1025 or equivalent). Calibration must be checked at the volumes 
employed in the test. Ground glass stopper is used to prevent 
evaporation of extracts.
    5.2.4  Evaporative flask, Kuderna-Danish--500-mL (Kontes K-570001-
0500 or equivalent). Attach to concentrator tube with springs.
    5.2.5  Snyder column, Kuderna-Danish--Three-ball macro (Kontes K-
503000-0121 or equivalent).
    5.2.6  Snyder column, Kuderna-Danish--Two-ball micro (Kontes K-
569001-0219 or equivalent).
    5.2.7  Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
    5.2.8  Chromatographic column--Approximately 400 mm long  x  22 mm 
ID, with Teflon stopcock and coarse frit filter disc at bottom (Kontes 
K-420540-0234 or equivalent), for use in Florisil column cleanup 
procedure.
    5.2.9  Chromatographic column--Approximately 300 mm long  x  10 mm 
ID, with Teflon stopcock and coarse frit filter disc at bottom (Kontes 
K-420540-0213 or equivalent), for use in alumina column cleanup 
procedure.
    5.3  Boiling chips--Approximately 10/40 mesh. Heat to 400  deg.C for 
30 min or Soxhlet extract with methylene chloride.
    5.4  Water bath--Heated, with concentric ring cover, capable of 
temperature control (2  deg.C). The bath should be used in a 
hood.
    5.5  Balance--Analytical, capable of accurately weighing 0.0001 g.
    5.6  Gas chromatograph--An analytical system complete with gas 
chromatograph suitable for on-column injection and all required 
accessories including syringes, analytical columns, gases, detector, and 
strip-chart recorder. A data system is recommended for measuring peak 
areas.
    5.6.1  Column 1--1.8 m long  x  4 mm ID glass, packed with 10% 
Carbowax 20 M/2% KOH on Chromosorb W-AW (80/100 mesh) or equivalent. 
This column was used to develop the method performance statements in 
Section 14. Guidelines for the use of alternate column packings are 
provided in Section 12.2.
    5.6.2  Column 2--1.8 m long x 4 mm ID glass, packed with 10% SP-2250 
on Supel- coport (100/120 mesh) or equivalent.
    5.6.3  Detector--Nitrogen-phosphorus, reductive Hall, or Thermal 
Energy Analyzer detector.\1\,\2\ These detectors have proven 
effective in the analysis of wastewaters for the parameters listed in 
the scope (Section 1.1). A nitrogen-phosphorus detector was used to 
develop the method performance statements in Section 14. Guidelines for 
the use of alternate detectors are provided in Section 12.2.

                               6. Reagents

    6.1  Reagent water--Reagent water is defined as a water in which an 
interferent is not observed at the MDL of the parameters of interest.
    6.2  Sodium hydroxide solution (10 N)--Dissolve 40 g of NaOH (ACS) 
in reagent water and dilute to 100 ml.

[[Page 102]]

    6.3  Sodium thiosulfate--(ACS) Granular.
    6.4  Sulfuric acid (1+1)--Slowly, add 50 mL of H2SO4 (ACS, 
sp. gr. 1.84) to 50 mL of reagent water.
    6.5  Sodium sulfate--(ACS) Granular, anhydrous. Purify by heating at 
400  deg.C for 4 h in a shallow tray.
    6.6  Hydrochloric acid (1+9)--Add one volume of concentrated HCl 
(ACS) to nine volumes of reagent water.
    6.7  Acetone, methanol, methylene chloride, pentane--Pesticide 
quality or equivalent.
    6.8  Ethyl ether--Nanograde, redistilled in glass if necessary.
    6.8.1  Ethyl ether must be shown to be free of peroxides before it 
is used as indicated by EM Laboratories Quant test strips. (Available 
from Scientific Products Co., Cat No. P1126-8, and other suppliers.)
    6.8.2  Procedures recommended for removal of peroxides are provided 
with the test strips. After cleanup, 20 mL of ethyl alcohol preservative 
must be added to each liter of ether.
    6.9  Florisil--PR grade (60/100 mesh). Purchase activated at 1250 
deg.F and store in the dark in glass containers with ground glass 
stoppers or foil-lined screw caps. Before use, activate each batch at 
least 16 h at 130  deg.C in a foil-covered glass container and allow to 
cool.
    6.10  Alumina--Basic activity Super I, W200 series (ICN Life 
Sciences Group, No. 404571, or equivalent). To prepare for use, place 
100 g of alumina into a 500-mL reagent bottle and add 2 mL of reagent 
water. Mix the alumina preparation thoroughly by shaking or rolling for 
10 min and let it stand for at least 2 h. The preparation should be 
homogeneous before use. Keep the bottle sealed tightly to ensure proper 
activity.
    6.11  Stock standard solutions (1.00 g/L)--Stock 
standard solutions can be prepared from pure standard materials or 
purchased as certified solutions.
    6.11.1  Prepare stock standard solutions by accurately weighing 
about 0.0100 g of pure material. Dissolve the material in methanol and 
dilute to volume in a 10-mL volumetric flask. Larger volumes can be used 
at the convenience of the analyst. When compound purity is assayed to be 
96% or greater, the weight can be used without correction to calculate 
the concentration of the stock standard. Commercially prepared stock 
standards can be used at any concentration if they are certified by the 
manufacturer or by an independent source.
    6.11.2  Transfer the stock standard solutions into Teflon-sealed 
screw-cap bottles. Store at 4  deg.C and protect from light. Stock 
standard solutions should be checked frequently for signs of degradation 
or evaporation, especially just prior to preparing calibration standards 
from them.
    6.11.3  Stock standard solutions must be replaced after six months, 
or sooner if comparison with check standards indicates a problem.
    6.12  Quality control check sample concentrate--See Section 8.2.1.

                             7. Calibration

    7.1  Establish gas chromatographic operating conditions equivalent 
to those given in Table 1. The gas chromatographic system can be 
calibrated using the external standard technique (Section 7.2) or the 
internal standard technique (Section 7.3).
    7.2  External standard calibration procedure:
    7.2.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask and diluting to volume 
with methanol. One of the external standards should be at a concentraton 
near, but above, the MDL (Table 1) and the other concentrations should 
correspond to the expected range of concentrations found in real samples 
or should define the working range of the detector.
    7.2.2  Using injections of 2 to 5 L, analyze each 
calibration standard according to Section 12 and tabulate peak height or 
area responses against the mass injected. The results can be used to 
prepare a calibration curve for each compound. Alternatively, if the 
ratio of response to amount injected (calibration factor) is a constant 
over the working range (< 10% relative standard deviation, RSD), 
linearity through the origin can be assumed and the average ratio or 
calibration factor can be used in place of a calibration curve.
    7.3  Internal standard calibration procedure--To use this approach, 
the analyst must select one or more internal standards that are similar 
in analytical behavior to the compounds of interest. The analyst must 
further demonstrate that the measurement of the internal standard is not 
affected by method or matrix interferences. Because of these 
limitations, no internal standard can be suggested that is applicable to 
all samples.
    7.3.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask. To each calibration 
standard, add a known constant amount of one or more internal standards, 
and dilute to volume with methanol. One of the standards should be at a 
concentration near, but above, the MDL and the other concentrations 
should correspond to the expected range of concentrations found in real 
samples or should define the working range of the detector.

[[Page 103]]

    7.3.2  Using injections of 2 to 5 L, analyze each 
calibration standard according to Section 12 and tabulate peak height or 
area responses against concentration for each compound and internal 
standard. Calculate response factors (RF) for each compound using 
Equation 1.

                                                                                                                
                                                                   RF=      (As)(Cis)    (Ais)(Cs)              
                                                                                                                

                                                              Equation 1
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Cis=Concentration of the internal standard (g/L).
    Cs=Concentration of the parameter to be measured (g/
L).
    If the RF value over the working range is a constant (<10% RSD), the 
RF can be assumed to be invariant and the average RF can be used for 
calculations. Alternatively, the results can be used to plot a 
calibration curve of response ratios, As/Ais, vs. RF.
    7.4  The working calibration curve, calibration factor, or RF must 
be verified on each working day by the measurement of one or more 
calibration standards. If the response for any parameter varies from the 
predicted response by more than 15%, a new calibration curve 
must be prepared for that compound.
    7.5  Before using any cleanup procedure, the analyst must process a 
series of calibration standards through the procedure to validate 
elution patterns and the absence of interferences from the reagents.

                           8. Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality control program. The minimum requirements of this program 
consist of an initial demonstration of laboratory capability and an 
ongoing analysis of spiked samples to evaluate and document data 
quality. The laboratory must maintain records to document the quality of 
data that is generated. Ongoing data quality checks are compared with 
established performance criteria to determine if the results of analyses 
meet the performance characteristics of the method. When results of 
sample spikes indicate atypical method performance, a quality control 
check standard must be analyzed to confirm that the measurements were 
performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occurring in 
chromatography, the analyst is permitted certain options (detailed in 
Sections 10.4, 11.1, and 12.2) to improve the separations or lower the 
cost of measurements. Each time such a modification is made to the 
method, the analyst is required to repeat the procedure in Section 8.2.
    8.1.3  Before processing any samples, the analyst must analyze a 
reagent water blank to demonstrate that interferences from the 
analytical system and glassware are under control. Each time a set of 
samples is extracted or reagents are changed, a reagent water blank must 
be processed as a safeguard against laboratory contamination.
    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 10% of all samples to monitor and evaluate laboratory data 
quality. This procedure is described in Section 8.3.
    8.1.5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 10% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.5.
    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality control (QC) check sample concentrate is required 
containing each parameter of interest at a concentration of 20 
g/mL in methanol. The QC check sample concentrate must be 
obtained from the U.S. Environmental Protection Agency, Environmental 
Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If 
not available from that source, the QC check sample concentrate must be 
obtained from another external source. If not available from either 
source above, the QC check sample concentrate must be prepared by the 
laboratory using stock standards prepared independently from those used 
for calibration.
    8.2.2  Using a pipet, prepare QC check samples at a concentration of 
20 g/L by adding 1.00 mL of QC check sample concentrate to each 
of four 1-L aliquots of reagent water.
    8.2.3  Analyze the well-mixed QC check samples according to the 
method beginning in Section 10.
    8.2.4  Calculate the average recovery (X) in g/L, and the 
standard deviation of the recovery (s) in g/L, for each 
parameter using the four results.
    8.2.5  For each parameter compare s and X with the corresponding 
acceptance criteria for precision and accuracy, respectively, found in 
Table 2. If s and X for all parameters of interest meet the acceptance 
criteria, the system performance is acceptable

[[Page 104]]

and analysis of actual samples can begin. If any individual s exceeds 
the precision limit or any individual X falls outside the range for 
accuracy, the system performance is unacceptable for that parameter. 
Locate and correct the source of the problem and repeat the test for all 
parameters of interest beginning with Section 8.2.2.
    8.3  The laboratory must, on an ongoing basis, spike at least 10% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing one to ten samples per month, at least one 
spiked sample per month is required.
    8.3.1  The concentration of the spike in the sample should be 
determined as follows:
    8.3.1.1  If, as in compliance monitoring, the concentration of a 
specific parameter in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of a specific parameter in the sample 
is not being checked against a limit specific to that parameter, the 
spike should be at 20 g/L or 1 to 5 times higher than the 
background concentration determined in Section 8.3.2, whichever 
concentration would be larger.
    8.3.1.3  If it is impractical to determine background levels before 
spiking (e.g., maximum holding times will be exceeded), the spike 
concentration should be (1) the regulatory concentration limit, if any; 
or, if none (2) the larger of either 5 times higher than the expected 
background concentration or 20 g/L.
    8.3.2  Analyze one sample aliquot to determine the background 
concentration (B) of each parameter. If necessary, prepare a new QC 
check sample concentrate (Section 8.2.1) appropriate for the background 
concentrations in the sample. Spike a second sample aliquot with 1.0 mL 
of the QC check sample concentrate and analyze it to determine the 
concentration after spiking (A) of each parameter. Calculate each 
percent recovery (P) as 100(A-B)%/T, where T is the known true value of 
the spike.
    8.3.3  Compare the percent recovery (P) for each parameter with the 
corresponding QC acceptance criteria found in Table 2. These acceptance 
criteria were caluclated to include an allowance for error in 
measurement of both the background and spike concentrations, assuming a 
spike to background ratio of 5:1. This error will be accounted for to 
the extent that the analyst's spike to background ratio approaches 
5:1.\18\ If spiking was performed at a concentration lower than 20 
g/L, the analyst must use either the QC acceptance criteria in 
Table 2, or optional QC acceptance criteria caluclated for the specific 
spike concentration. To calculate optional acceptance crtieria for the 
recovery of a parameter: (1) Calculate accuracy (X') using the equation 
in Table 3, substituting the spike concentration (T) for C; (2) 
calculate overall precision (S') using the equation in Table 3, 
substituting X' for X; (3) calculate the range for recovery at the spike 
concentration as (100 X'/T)  2.44(100 S'/T)%.\18\
    8.3.4  If any individual P falls outside the designated range for 
recovery, that parameter has failed the acceptance criteria. A check 
standard containing each parameter that failed the criteria must be 
analyzed as described in Section 8.4.
    8.4  If any parameter fails the acceptance criteria for recovery in 
Section 8.3, a QC check standard containing each parameter that failed 
must be prepared and analyzed.

    Note: The frequency for the required analysis of a QC check standard 
will depend upon the number of parameters being simultaneously tested, 
the complexity of the sample matrix, and the performance of the 
laboratory.

    8.4.1  Prepare the QC check standard by adding 1.0 mL of QC check 
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The 
QC check standard needs only to contain the parameters that failed 
criteria in the test in Section 8.3.
    8.4.2  Analyze the QC check standard to determine the concentration 
measured (A) of each parameter. Calculate each percent recovery 
(Ps) as 100 (A/T)%, where T is the true value of the standard 
concentration.
    8.4.3  Compare the percent recovery (Ps) for each parameter 
with the corresponding QC acceptance criteria found in Table 2. Only 
parameters that failed the test in Section 8.3 need to be compared with 
these criteria. If the recovery of any such parameter falls outside the 
designated range, the laboratory performance for that parameter is 
judged to be out of control, and the problem must be immediately 
identified and corrected. The analytical result for that parameter in 
the unspiked sample is suspect and may not be reported for regulatory 
compliance purposes.
    8.5  As part of the QC program for the laboratory, method accuracy 
for wastewater samples must be assessed and records must be maintained. 
After the analysis of five spiked wastewater samples as in Section 8.3, 
calculate the average percent recovery (P) and the standard deviation of 
the percent recovery (sp). Express the accuracy assessment as a 
percent recovery interval from P-2sp to P+2sp. If P=90% and 
sp=10%, for example, the accuracy interval is expressed as 70-110%. 
Update the accuracy assessment for each parameter on a regular basis 
(e.g. after each five to ten new accuracy measurements).
    8.6  It is recommended that the laboratory adopt additional quality 
assurance practices for use with this method. The specific practices 
that are most productive depend upon the needs of the laboratory and the 
nature of

[[Page 105]]

the samples. Field duplicates may be analyzed to assess the precision of 
the environmental measurements. When doubt exists over the 
identification of a peak on the chromatogram, confirmatory techniques 
such as gas chromatography with a dissimilar column, specific element 
detector, or mass spectrometer must be used. Whenever possible, the 
laboratory should analyze standard reference materials and participate 
in relevant performance evaluation studies.

            9. Sample Collection, Preservation, and Handling

    9.1  Grab samples must be collected in glass containers. 
Conventional sampling practices \19\ should be followed, except that the 
bottle must not be prerinsed with sample before collection. Composite 
samples should be collected in refrigerated glass containers in 
accordance with the requirements of the program. Automatic sampling 
equipment must be as free as possible of Tygon tubing and other 
potential sources of contamination.
    9.2  All samples must be iced or refrigerated at 4  deg.C from the 
time of collection until extraction. Fill the sample bottles and, if 
residual chlorine is present, add 80 mg of sodium thiosulfate per liter 
of sample and mix well. EPA Methods 330.4 and 330.5 may be used for 
measurement of residual chlorine.\20\ Field test kits are available for 
this purpose. If N-nitrosodiphenylamine is to be determined, adjust the 
sample pH to 7 to 10 with sodium hydroxide solution or sulfuric acid.
    9.3  All samples must be extracted within 7 days of collection and 
completely analyzed within 40 days of extraction.\4\
    9.4  Nitrosamines are known to be light sensitive.\7\ Samples should 
be stored in amber or foil-wrapped bottles in order to minimize 
photolytic decomposition.

                          10. Sample Extraction

    10.1  Mark the water meniscus on the side of the sample bottle for 
later determination of sample volume. Pour the entire sample into a 2-L 
separatory funnel. Check the pH of the sample with wide-range pH paper 
and adjust to within the range of 5 to 9 with sodium hydroxide solution 
or sulfuric acid.
    10.2  Add 60 mL of methylene chloride to the sample bottle, seal, 
and shake 30 s to rinse the inner surface. Transfer the solvent to the 
separatory funnel and extract the sample by shaking the funnel for 2 min 
with periodic venting to release excess pressure. Allow the organic 
layer to separate from the water phase for a minimum of 10 min. If the 
emulsion interface between layers is more than one-third the volume of 
the solvent layer, the analyst must employ mechanical techniques to 
complete the phase separation. The optimum technique depends upon the 
sample, but may include stirring, filtration of the emulsion through 
glass wool, centrifugation, or other physical methods. Collect the 
methylene chloride extract in a 250-mL Erlenmeyer flask.
    10.3  Add a second 60-mL volume of methylene chloride to the sample 
bottle and repeat the extraction procedure a second time, combining the 
extracts in the Erlenmeyer flask. Perform a third extraction in the same 
manner.
    10.4  Assemble a Kuderna-Danish (K-D) concentrator by attaching a 
10-mL concentrator tube to a 500-mL evaporative flask. Other 
concentration devices or techniques may be used in place of the K-D 
concentrator if the requirements of Section 8.2 are met.
    10.5  Add 10 mL of hydrochloric acid to the combined extracts and 
shake for 2 min. Allow the layers to separate. Pour the combined extract 
through a solvent-rinsed drying column containing about 10 cm of 
anhydrous sodium sulfate, and collect the extract in the K-D 
concentrator. Rinse the Erlenmeyer flask and column with 20 to 30 mL of 
methylene chloride to complete the quantitative transfer.
    10.6  Add one or two clean boiling chips to the evaporative flask 
and attach a three-ball Snyder column. Prewet the Snyder column by 
adding about 1 mL of methylene chloride to the top. Place the K-D 
apparatus on a hot water bath (60 to 65 deg.C) so that the concentrator 
tube is partially immersed in the hot water, and the entire lower 
rounded surface of the flask is bathed with hot vapor. Adjust the 
vertical position of the apparatus and the water temperature as required 
to complete the concentration in 15 to 20 min. At the proper rate of 
distillation the balls of the column will actively chatter but the 
chambers will not flood with condensed solvent. When the apparent volume 
of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain 
and cool for at least 10 min.
    10.7  Remove the Snyder column and rinse the flask and its lower 
joint into the concentrator tube with 1 to 2 mL of methylene chloride. A 
5-mL syringe is recommended for this operation. Stopper the concentrator 
tube and store refrigerated if further processing will not be performed 
immediately. If the extract will be stored longer than two days, it 
should be transferred to a Teflon-sealed screw-cap vial. If N-
nitrosodiphenylamine is to be measured by gas chromatography, the 
analyst must first use a cleanup column to eliminate diphenylamine 
interference (Section 11). If N-nitrosodiphenylamine is of no interest, 
the analyst may proceed directly with gas chromatographic analysis 
(Section 12).
    10.8  Determine the original sample volume by refilling the sample 
bottle to the mark and transferring the liquid to a 1000- 

[[Page 106]]

mL graduated cylinder. Record the sample volume to the nearest 5 mL.

                       11. Cleanup and Separation

    11.1  Cleanup procedures may not be necessary for a relatively clean 
sample matrix. If particular circumstances demand the use of a cleanup 
procedure, the analyst may use either procedure below or any other 
appropriate procedure. However, the analyst first must demonstrate that 
the requirements of Section 8.2 can be met using the method as revised 
to incorporate the cleanup procedure. Diphenylamine, if present in the 
original sample extract, must be separated from the nitrosamines if N-
nitrosodiphenylamine is to be determined by this method.
    11.2  If the entire extract is to be cleaned up by one of the 
following procedures, it must be concentrated to 2.0 mL. To the 
concentrator tube in Section 10.7, add a clean boiling chip and attach a 
two-ball micro-Snyder column. Prewet the column by adding about 0.5 mL 
of methylene chloride to the top. Place the micr-K-D apparatus on a hot 
water bath (60 to 65  deg.C) so that the concentrator tube is partially 
immersed in the hot water. Adjust the vertical position of the apparatus 
and the water temperature as required to complete the concentration in 5 
to 10 min. At the proper rate of distillation the balls of the column 
will actively chatter but the chambers will not flood. When the apparent 
volume of liquid reaches about 0.5 mL, remove the K-D apparatus and 
allow it to drain and cool for at least 10 min. Remove the micro-Snyder 
column and rinse its lower joint into the concentrator tube with 0.2 mL 
of methylene chloride. Adjust the final volume to 2.0 mL and proceed 
with one of the following cleanup procedures.
    11.3  Florisil column cleanup for nitrosamines:
    11.3.1  Place 22 g of activated Florisil into a 22-mm ID 
chromatographic column. Tap the column to settle the Florisil and add 
about 5 mm of anhydrous sodium sulfate to the top.
    11.3.2  Preelute the column with 40 mL of ethyl ether/pentane 
(15+85)(V/V). Discard the eluate and just prior to exposure of the 
sodium sulfate layer to the air, quantitatively transfer the 2-mL sample 
extract onto the column using an additional 2 mL of pentane to complete 
the transfer.
    11.3.3  Elute the column with 90 mL of ethyl ether/pentane 
(15+85)(V/V) and discard the eluate. This fraction will contain the 
diphenylamine, if it is present in the extract.
    11.3.4  Next, elute the column with 100 mL of acetone/ethyl ether 
(5+95)(V/V) into a 500-mL K-D flask equipped with a 10-mL concentrator 
tube. This fraction will contain all of the nitrosamines listed in the 
scope of the method.
    11.3.5  Add 15 mL of methanol to the collected fraction and 
concentrate as in Section 10.6, except use pentane to prewet the column 
and set the water bath at 70 to 75  deg.C. When the apparatus is cool, 
remove the Snyder column and rinse the flask and its lower joint into 
the concentrator tube with 1 to 2 mL of pentane. Analyze by gas 
chromatography (Section 12).
    11.4  Alumina column cleanup for nitrosamines:
    11.4.1  Place 12 g of the alumina preparation (Section 6.10) into a 
10-mm ID chromatographic column. Tap the column to settle the alumina 
and add 1 to 2 cm of anhydrous sodium sulfate to the top.
    11.4.2  Preelute the column with 10 mL of ethyl ether/pentane 
(3+7)(V/V). Discard the eluate (about 2 mL) and just prior to exposure 
of the sodium sulfate layer to the air, quantitatively transfer the 2 mL 
sample extract onto the column using an additional 2 mL of pentane to 
complete the transfer.
    11.4.3  Just prior to exposure of the sodium sulfate layer to the 
air, add 70 mL of ethyl ether/pentane (3+7)(V/V). Discard the first 10 
mL of eluate. Collect the remainder of the eluate in a 500-mL K-D flask 
equipped with a 10 mL concentrator tube. This fraction contains N-
nitrosodiphenylamine and probably a small amount of N-nitrosodi-n-
propylamine.
    11.4.4  Next, elute the column with 60 mL of ethyl ether/pentane 
(1+1)(V/V), collecting the eluate in a second K-D flask equipped with a 
10-mL concentrator tube. Add 15 mL of methanol to the K-D flask. This 
fraction will contain N-nitrosodimethylamine, most of the N-nitrosodi-n-
propylamine and any diphenylamine that is present.
    11.4.5  Concentrate both fractions as in Section 10.6, except use 
pentane to prewet the column. When the apparatus is cool, remove the 
Snyder column and rinse the flask and its lower joint into the 
concentrator tube with 1 to 2 mL of pentane. Analyze the fractions by 
gas chromatography (Section 12).

                         12. Gas Chromatography

    12.1  N-nitrosodiphenylamine completely reacts to form diphenylamine 
at the normal operating temperatures of a GC injection port (200 to 250  
deg.C). Thus, N-nitrosodiphenylamine is chromatographed and detected as 
diphenylamine. Accurate determination depends on removal of 
diphenylamine that may be present in the original extract prior to GC 
analysis (See Section 11).
    12.2  Table 1 summarizes the recommended operating conditions for 
the gas chromatograph. Included in this table are retention times and 
MDL that can be achieved under these conditions. Examples of the 
separations achieved by Column 1 are shown in Figures 1 and 2. Other 
packed or capillary (open-tubular) columns, chromatographic conditions, 
or detectors may be used if the requirements of Section 8.2 are met.

[[Page 107]]

    12.3  Calibrate the system daily as described in Section 7.
    12.4  If the extract has not been subjected to one of the cleanup 
procedures in Section 11, it is necessary to exchange the solvent from 
methylene chloride to methanol before the thermionic detector can be 
used. To a 1 to 10-mL volume of methylene chloride extract in a 
concentrator tube, add 2 mL of methanol and a clean boiling chip. Attach 
a two-ball micro-Snyder column to the concentrator tube. Prewet the 
column by adding about 0.5 mL of methylene chloride to the top. Place 
the micro-K-D apparatus on a boiling (100  deg.C) water bath so that the 
concentrator tube is partially immersed in the hot water. Adjust the 
vertical position of the apparatus and the water temperature as required 
to complete the concentration in 5 to 10 min. At the proper rate of 
distillation the balls of the column will actively chatter but the 
chambers will not flood. When the apparent volume of liquid reaches 
about 0.5 mL, remove the K-D apparatus and allow it to drain and cool 
for at least 10 min. Remove the micro-Snyder column and rinse its lower 
joint into the concentrator tube with 0.2 mL of methanol. Adjust the 
final volume to 2.0 mL.
    12.5  If the internal standard calibration procedure is being used, 
the internal standard must be added to the sample extract and mixed 
thoroughly immediately before injection into the gas chromatograph.
    12.6  Inject 2 to 5 L of the sample extract or standard 
into the gas chromatograph using the solvent-flush technique.\21\ 
Smaller (1.0 L) volumes may be injected if automatic devices 
are employed. Record the volume injected to the nearest 0.05 L, 
and the resulting peak size in area or peak height units.
    12.7  Identify the parameters in the sample by comparing the 
retention times of the peaks in the sample chromatogram with those of 
the peaks in standard chromatograms. The width of the retention time 
window used to make identifications should be based upon measurements of 
actual retention time variations of standards over the course of a day. 
Three times the standard deviation of a retention time for a compound 
can be used to calculate a suggested window size; however, the 
experience of the analyst should weigh heavily in the interpretation of 
chromatograms.
    12.8  If the response for a peak exceeds the working range of the 
system, dilute the extract and reanalyze.
    12.9  If the measurement of the peak response is prevented by the 
presence of interferences, further cleanup is required.

                            13. Calculations

    13.1  Determine the concentration of individual compounds in the 
sample.
    13.1.1  If the external standard calibration procedure is used, 
calculate the amount of material injected from the peak response using 
the calibration curve or calibration factor determined in Section 7.2.2. 
The concentration in the sample can be calculated from Equation 2.

                                                                                                                
                                                                           (A)(Vt)                              
                                        Concentration (g/  = -----------------                         
                                                    L)                     (Vi)(Vs)                             
                                                                                                                

                                                              Equation 2
where:
    A=Amount of material injected (ng).
    Vi=Volume of extract injected (L).
    Vt=Volume of total extract (L).
    Vs=Volume of water extracted (mL).

    13.1.2  If the internal standard calibration procedure is used, 
calculate the concentration in the sample using the response factor (RF) 
determined in Section 7.3.2 and Equation 3.

                                                                        
                                          (As)(Cis)                     
                                    RF=  -----------                    
                                          (Ais)(Cs)                     
                                                                        

                                                              Equation 3
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Is=Amount of internal standard added to each extract 
(g).
    Vo=Volume of water extracted (L).

    13.2  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

                         14. Method Performance

    14.1  The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the value is above zero.\3\ The MDL concentrations 
listed in Table 1 were obtained using reagent water.\22\ Similar results 
were achieved using representative wastewaters. The MDL actually 
achieved in a given analysis will vary depending on instrument 
sensitivity and matrix effects.
    14.2  This method has been tested for linearity of spike recovery 
from reagent water and has been demonstrated to be applicable over the 
concentration range from 4 x MDL to 1000 x MDL.\22\
    14.3  This method was tested by 17 laboratories using reagent water, 
drinking water, surface water, and three industrial wastewaters spiked 
at six concentrations over the range 0.8 to 55 g/L.\23\ Single 
operator precision, overall precision, and method accuracy were found to 
be directly related to

[[Page 108]]

the concentration of the parameter and essentially independent of the 
sample matrix. Linear equations to describe these relationships are 
presented in Table 3.

                               References

    1. Fine, D.H., Lieb, D., and Rufeh, R. ``Principle of Operation of 
the Thermal Energy Analyzer for the Trace Analysis of Volatile and Non-
volatile N-nitroso Compounds,'' Journal of Chromatography, 107, 351 
(1975).
    2. Fine, D.H., Hoffman, F., Rounbehler, D.P., and Belcher, N.M. 
``Analysis of N-nitroso Compounds by Combined High Performance Liquid 
Chromatography and Thermal Energy Analysis,'' Walker, E.A., Bogovski, P. 
and Griciute, L., Editors, N-nitroso Compounds--Analysis and Formation, 
Lyon, International Agency for Research on Cancer (IARC Scientific 
Publications No. 14), pp. 43-50 (1976).
    3. 40 CFR part 136, appendix B.
    4. ``Determination of Nitrosamines in Industrial and Municipal 
Wastewaters,'' EPA 600/4-82-016, National Technical Information Service, 
PB82-199621, Springfield, Virginia 22161, April 1982.
    5. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard 
Practices for Preparation of Sample Containers and for Preservation of 
Organic Constituents,'' American Society for Testing and Materials, 
Philadelphia.
    6. Buglass, A.J., Challis, B.C., and Osborn, M.R. ``Transnitrosation 
and Decomposition of Nitrosamines,'' Bogovski, P. and Walker, E.A., 
Editors, N-nitroso Compounds in the Environment, Lyon, International 
Agency for Research on Cancer (IARC Scientific Publication No. 9), pp. 
94-100 (1974).
    7. Burgess, E.M., and Lavanish, J.M. ``Photochemical Decomposition 
of N-nitrosamines,'' Tetrahedon Letters, 1221 (1964)
    8. Druckrey, H., Preussmann, R., Ivankovic, S., and Schmahl, D. 
``Organotrope Carcinogene Wirkungen bei 65 Verschiedenen N-
NitrosoVerbindungen an BD-Ratten,'' Z. Krebsforsch., 69, 103 (1967).
    9. Fiddler, W. ``The Occurrence and Determination of N-nitroso 
Compounds,'' Toxicol. Appl. Pharmacol., 31, 352 (1975).
    10. ``Carcinogens--Working With Carcinogens,'' Department of Health, 
Education, and Welfare, Public Health Service, Center for Disease 
Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    11. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR 
Part 1910), Occupational Safety and Health Administration, OSHA 2206 
(Revised, January 1976).
    12. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    13. Lijinsky, W. ``How Nitrosamines Cause Cancer,'' New Scientist, 
73, 216 (1977).
    14. Mirvish, S.S. ``N-Nitroso compounds: Their Chemical and in vivo 
Formation and Possible Importance as Environmental Carcinogens,'' J. 
Toxicol. Environ. Health, 3, 1267 (1977).
    15. ``Reconnaissance of Environmental Levels of Nitrosamines in the 
Central United States,'' EPA-330/1-77-001, National Enforcement 
Investigations Center, U.S. Environmental Protection Agency (1977).
    16. ``Atmospheric Nitrosamine Assessment Report,'' Office of Air 
Quality Planning and Standards, U.S. Environmental Protection Agency, 
Research Triangle Park, North Carolina (1976).
    17. ``Scientific and Technical Assessment Report on Nitrosamines,'' 
EPA-660/6-7-001, Office of Research and Development, U.S. Environmental 
Protection Agency (1976).
    18. Provost, L.P., and Elder, R.S. ``Interpretation of Percent 
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44 
used in the equation in Section 8.3.3 is two times the value of 1.22 
derived in this report.)
    19. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard 
Practices for Sampling Water,'' American Society for Testing and 
Materials, Philadelphia.
    20. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for 
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory, Cincinnati, Ohio 45268, March 1979.
    21. Burke, J. A. ``Gas Chromatography for Pesticide Residue 
Analysis; Some Practical Aspects,'' Journal of the Association of 
Official Analytical Chemists, 48, 1037 (1965).
    22. ``Method Detection Limit and Analytical Curve Studies EPA 
Methods 606, 607, and 608,'' Special letter report for EPA Contract 68-
03-2606, U.S. Environmental Protection Agency, Environmental Monitoring 
and Support Laboratory, Cincinnati, Ohio 45268, June 1980.
    23. ``EPA Method Study 17 Method 607--Nitrosamines,'' EPA 600/4-84-
051, National Technical Information Service, PB84-207646, Springfield, 
Virginia 22161, June 1984.

     Table 1--Chromatographic Conditions and Method Detection Limits    
------------------------------------------------------------------------
                                            Retention time     Method   
                                                 (min)        detection 
                 Parameter                 ----------------     limit   
                                            Column  Column  (g/
                                               1       2         L)     
------------------------------------------------------------------------
N-Nitrosodimethylamine....................     4.1    0.88          0.15
N-Nitrosodi-n-propylamine.................    12.1     4.2           .46

[[Page 109]]

                                                                        
N-Nitrosodiphenylamine a..................  b 12.8   c 6.4           .81
------------------------------------------------------------------------
Column 1 conditions: Chromosorb W-AW (80/100 mesh) coated with 10%      
  Carbowax 20 M/2% KOH packed in a 1.8 m long x 4mm ID glass column with
  helium carrier gas at 40 mL/min flow rate. Column temperature held    
  isothermal at 110 C, except where otherwise indicated.                
Column 2 conditions: Supelcoport (100/120 mesh) coated with 10% SP-2250 
  packed in a 1.8 m long x 4 mm ID glass column with helium carrier gas 
  at 40 mL/min flow rate. Column temperature held isothermal at 120 C,  
  except where otherwise indicated.                                     
                                                                        
a Measured as diphenylamine.                                            
b 220 C column temperature.                                             
c 210 C column temperature.                                             


                                   Table 2--QC Acceptance Criteria--Method 607                                  
----------------------------------------------------------------------------------------------------------------
                                                                                        Range for X             
                                                            Test conc.    Limit for s  (g/   Range for 
                        Parameter                          (g/  (g/       L)          P, Ps   
                                                                L)            L)                      (percent) 
----------------------------------------------------------------------------------------------------------------
N-Nitrosodimethylamine...................................            20           3.4      4.6-20.0       13-109
N-Nitrosodiphenyl........................................            20           6.1      2.1-24.5        D-139
N-Nitrosodi-n-propylamine................................            20           5.7     11.5-26.8      45-146 
----------------------------------------------------------------------------------------------------------------
s=Standard deviation for four recovery measurements, in g/L (Section 8.2.4).                           
X=Average recovery for four recovery measurements, in g/L (Section 8.2.4).                             
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).                                                 
D=Detected; result must be greater than zero.                                                                   
                                                                                                                
Note: These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits
  for recovery have been broadened to assure applicability of the limits to concentrations below those used to  
  develop Table 3.                                                                                              


                Table 3--Method Accuracy and Precision as Functions of Concentration--Method 607                
----------------------------------------------------------------------------------------------------------------
                                                                   Accuracy, as   Single analyst      Overall   
                            Parameter                               recovery, X    precision, sr   precision, S 
                                                                  (g/L)  (g/L)  (g/L)
----------------------------------------------------------------------------------------------------------------
N-Nitrosodimethylamine..........................................      0.37C+0.06      0.25X-0.04      0.25X+0.11
N-Nitrosodiphenylamine..........................................      0.64C+0.52      0.36X-1.53      0.46X-0.47
N-Nitrosodi-n-propylamine.......................................      0.96C-0.07      0.15X+0.13      0.21X+0.15
----------------------------------------------------------------------------------------------------------------
X=Expected recovery for one or more measurements of a sample containing a concentration of C, in g/L.  
sr=Expected single analyst standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
S=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
C=True value for the concentration, in g/L.                                                            
X=Average recovery found for measurements of samples containing a concentration of C, in g/L.          


[[Page 110]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.017

  
  
  
  
  
  
  

[[Page 111]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.018


  
  
  
  
  
  
  

[[Page 112]]

             Method 608--Organochlorine Pesticides and PCBs

                        1. Scope and Application

    1.1  This method covers the determination of certain organochlorine 
pesticides and PCBs. The following parameters can be determined by this 
method:

------------------------------------------------------------------------
                  Parameter                    STORET No.      CAS No.  
------------------------------------------------------------------------
Aldrin......................................         39330      309-00-2
-BHC...............................         39337      319-84-6
-BHC...............................         39338      319-85-7
-BHC...............................         34259      319-86-8
-BHC...............................         39340       58-89-9
Chlordane...................................         39350       57-74-9
4,4-DDD.....................................         39310       72-54-8
4,4-DDE.....................................         39320       72-55-9
4,4-DDT.....................................         39300       50-29-3
Dieldrin....................................         39380       60-57-1
Endosulfan I................................         34361      959-98-8
Endosulfan II...............................         34356    33212-65-9
Endosulfan sulfate..........................         34351     1031-07-8
Eldrin......................................         39390       72-20-8
Endrin aldehyde.............................         34366     7421-93-4
Heptachlor..................................         39410       76-44-8
Heptachlor epoxide..........................         39420     1024-57-3
Toxaphene...................................         39400     8001-35-2
PCB-1016....................................         34671    12674-11-2
PCB-1221....................................         39488     1104-28-2
PCB-1232....................................         39492    11141-16-5
PCB-1242....................................         39496    53469-21-9
PCB-1248....................................         39500    12672-29-6
PCB-1254....................................         39504    11097-69-1
PCB-1260....................................         39508    11096-82-5
------------------------------------------------------------------------

    1.2  This is a gas chromatographic (GC) method applicable to the 
determination of the compounds listed above in municipal and industrial 
discharges as provided under 40 CFR 136.1. When this method is used to 
analyze unfamiliar samples for any or all of the compounds above, 
compound identifications should be supported by at least one additional 
qualitative technique. This method describes analytical conditions for a 
second gas chromatographic column that can be used to confirm 
measurements made with the primary column. Method 625 provides gas 
chromatograph/mass spectrometer (GC/MS) conditions appropriate for the 
qualitative and quantitative confirmation of results for all of the 
parameters listed above, using the extract produced by this method.
    1.3  The method detection limit (MDL, defined in Section 14.1)\1\ 
for each parameter is listed in Table 1. The MDL for a specific 
wastewater may differ from those listed, depending upon the nature of 
interferences in the sample matrix.
    1.4  The sample extraction and concentration steps in this method 
are essentially the same as in Methods 606, 609, 611, and 612. Thus, a 
single sample may be extracted to measure the parameters included in the 
scope of each of these methods. When cleanup is required, the 
concentration levels must be high enough to permit selecting aliquots, 
as necessary, to apply appropriate cleanup procedures. The analyst is 
allowed the latitude, under Section 12, to select chromatographic 
conditions appropriate for the simultaneous measurement of combinations 
of these parameters.
    1.5  Any modification of this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5.
    1.6  This method is restricted to use by or under the supervision of 
analysts experienced in the use of a gas chromatograph and in the 
interpretation of gas chromatograms. Each analyst must demonstrate the 
ability to generate acceptable results with this method using the 
procedure described in Section 8.2.

                          2. Summary of Method

    2.1  A measured volume of sample, approximately 1-L, is extracted 
with methylene chloride using a separatory funnel. The methylene 
chloride extract is dried and exchanged to hexane during concentration 
to a volume of 10 mL or less. The extract is separated by gas 
chromatography and the parameters are then measured with an electron 
capture detector.\2\
    2.2  The method provides a Florisil column cleanup procedure and an 
elemental sulfur removal procedure to aid in the elimination of 
interferences that may be encountered.

                            3. Interferences

    3.1  Method interferences may be caused by contaminants in solvents, 
reagents, glassware, and other sample processing hardware that lead to 
discrete artifacts and/or elevated baselines in gas chromatograms. All 
of these materials must be routinely demonstrated to be free from 
interferences under the conditions of the analysis by running laboratory 
reagent blanks as described in Section 8.1.3.
    3.1.1  Glassware must be scrupulously cleaned.\3\ Clean all 
glassware as soon as possible after use by rinsing with the last solvent 
used in it. Solvent rinsing should be followed by detergent washing with 
hot water, and rinses with tap water and distilled water. The glassware 
should then be drained dry, and heated in a muffle furnace at 400  deg.C 
for 15 to 30 min. Some thermally stable materials, such as PCBs, may not 
be eliminated by this treatment. Solvent rinses with acetone and 
pesticide quality hexane may be substituted for the muffle furnace 
heating. Thorough rinsing with such solvents usually eliminates PCB 
interference. Volumetric ware should not be heated in a muffle furnace. 
After drying and cooling, glassware should be sealed and stored in a 
clean environment to prevent any accumulation of dust or other 
contaminants. Store inverted or capped with aluminum foil.

[[Page 113]]

    3.1.2  The use of high purity reagents and solvents helps to 
minimize interference problems. Purification of solvents by distillation 
in all-glass systems may be required.
    3.2  Interferences by phthalate esters can pose a major problem in 
pesticide analysis when using the electron capture detector. These 
compounds generally appear in the chromatogram as large late eluting 
peaks, especially in the 15 and 50% fractions from Florisil. Common 
flexible plastics contain varying amounts of phthalates. These 
phthalates are easily extracted or leached from such materials during 
laboratory operations. Cross contamination of clean glassware routinely 
occurs when plastics are handled during extraction steps, especially 
when solvent-wetted surfaces are handled. Interferences from phthalates 
can best be minimized by avoiding the use of plastics in the laboratory. 
Exhaustive cleanup of reagents and glassware may be required to 
eliminate background phthalate contamination.\4\,\5\ The 
interferences from phthalate esters can be avoided by using a 
microcoulometric or electrolytic conductivity detector.
    3.3  Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary 
considerably from source to source, depending upon the nature and 
diversity of the industrial complex or municipality being sampled. The 
cleanup procedures in Section 11 can be used to overcome many of these 
interferences, but unique samples may require additional cleanup 
approaches to achieve the MDL listed in Table 1.

                                4. Safety

    4.1  The toxicity or carcinogenicity of each reagent used in this 
method has not been precisely defined; however, each chemical compound 
should be treated as a potential health hazard. From this viewpoint, 
exposure to these chemicals must be reduced to the lowest possible level 
by whatever means available. The laboratory is responsible for 
maintaining a current awareness file of OSHA regulations regarding the 
safe handling of the chemicals specified in this method. A reference 
file of material data handling sheets should also be made available to 
all personnel involved in the chemical analysis. Additional references 
to laboratory safety are available and have been identified 6-8 for 
the information of the analyst.
    4.2  The following parameters covered by this method have been 
tentatively classified as known or suspected, human or mammalian 
carcinogens: 4,4'-DDT, 4,4'-DDD, the BHCs, and the PCBs. Primary 
standards of these toxic compounds should be prepared in a hood. A 
NIOSH/MESA approved toxic gas respirator should be worn when the analyst 
handles high concentrations of these toxic compounds.

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete or composite sampling.
    5.1.1  Grab sample bottle--1-L or 1-qt, amber glass, fitted with a 
screw cap lined with Teflon. Foil may be substituted for Teflon if the 
sample is not corrosive. If amber bottles are not available, protect 
samples from light. The bottle and cap liner must be washed, rinsed with 
acetone or methylene chloride, and dried before use to minimize 
contamination.
    5.1.2  Automatic sampler (optional)--The sampler must incorporate 
glass sample containers for the collection of a minimum of 250 mL of 
sample. Sample containers must be kept refrigerated at 4 deg.C and 
protected from light during composting. If the sampler uses a 
peristaltic pump, a minimum length of compressible silicone rubber 
tubing may be used. Before use, however, the compressible tubing should 
be thoroughly rinsed with methanol, followed by repeated rinsings with 
distilled water to minimize the potential for contamination of the 
sample. An integrating flow meter is required to collect flow 
proportional composites.
    5.2.  Glassware (All specifications are suggested. Catalog numbers 
are included for illustration only.):
    5.2.1  Separatory funnel--2-L, with Teflon stopcock.
    5.2.2  Drying column--Chromatographic column, approximately 400 mm 
long  x  19 mm ID, with coarse frit filter disc.
    5.2.3  Chromatographic column--400 mm long  x  22 mm ID, with Teflon 
stopcock and coarse frit filter disc (Kontes K-42054 or equivalent).
    5.2.4  Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes 
K-570050-1025 or equivalent). Calibration must be checked at the volumes 
employed in the test. Ground glass stopper is used to prevent 
evaporation of extracts.
    5.2.5  Evaporative flask, Kuderna-Danish--500-mL (Kontes K-570001-
0500 or equivalent). Attach to concentrator tube with springs.
    5.2.6  Snyder column, Kuderna/Danish--Three-ball macro (Kontes K-
503000-0121 or equivalent).
    5.2.7  Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
    5.3  Boiling chips--Approximately 10/40 mesh. Heat to 400 deg.C for 
30 min or Soxhlet extract with methylene chloride.
    5.4  Water bath--Heated, with concentric ring cover, capable of 
temperature control (2 deg.C). The bath should be used in a 
hood.
    5.5  Balance--Analytical, capable of accurately weighing 0.0001 g.
    5.6  Gas chromatograph--An analytical system complete with gas 
chromatograph suitable for on-column injection and all required 
accessories including syringes, analytical columns, gases, detector, and 
strip- 

[[Page 114]]

chart recorder. A data system is recommended for measuring peak areas.
    5.6.1  Column 1--1.8 m long  x  4 mm ID glass, packed with 1.5% SP-
2250/1.95% SP-2401 on Supelcoport (100/120 mesh) or equivalent. This 
column was used to develop the method performance statements in Section 
14. Guidelines for the use of alternate column packings are provided in 
Section 12.1.
    5.6.2  Column 2--1.8 m long  x  4 mm ID glass, packed with 3% OV-1 
on Supelcoport (100/120 mesh) or equivalent.
    5.6.3  Detector--Electron capture detector. This detector has proven 
effective in the analysis of wastewaters for the parameters listed in 
the scope (Section 1.1), and was used to develop the method performance 
statements in Section 14. Guidelines for the use of alternate detectors 
are provided in Section 12.1.

                               6. Reagents

    6.1  Reagent water--Reagent water is defined as a water in which an 
interferent is not observed at the MDL of the parameters of interest.
    6.2  Sodium hydroxide solution (10 N)--Dissolve 40 g of NaOH (ACS) 
in reagent water and dilute to 100 mL.
    6.3  Sodium thiosulfate--(ACS) Granular.
    6.4  Sulfuric acid (1+1)--Slowly, add 50 mL to H2SO4 (ACS, 
sp. gr. 1.84) to 50 mL of reagent water.
    6.5  Acetone, hexane, isooctane, methylene chloride--Pesticide 
quality or equivalent.
    6.6  Ethyl ether--Nanograde, redistilled in glass if necessary.
    6.6.1  Ethyl ether must be shown to be free of peroxides before it 
is used as indicated by EM Laboratories Quant test strips. (Available 
from Scientific Products Co., Cat. No. P1126-8, and other suppliers.)
    6.6.2  Procedures recommended for removal of peroxides are provided 
with the test strips. After cleanup, 20 mL of ethyl alcohol preservative 
must be added to each liter of ether.
    6.7  Sodium sulfate--(ACS) Granular, anhydrous. Purify by heating at 
400  deg.C for 4 h in a shallow tray.
    6.8  Florisil--PR grade (60/100 mesh). Purchase activated at 1250  
deg.F and store in the dark in glass containers with ground glass 
stoppers or foil-lined screw caps. Before use, activate each batch at 
least 16 h at 130  deg.C in a foil-covered glass container and allow to 
cool.
    6.9  Mercury--Triple distilled.
    6.10  Copper powder--Activated.
    6.11  Stock standard solutions (1.00 g/L)--Stock 
standard solutions can be prepared from pure standard materials or 
purchased as certified solutions.
    6.11.1  Prepare stock standard solutions by accurately weighing 
about 0.0100 g of pure material. Dissolve the material in isooctane and 
dilute to volume in a 10-mL volumetric flask. Larger volumes can be used 
at the convenience of the analyst. When compound purity is assayed to be 
96% or greater, the weight can be used without correction to calculate 
the concentration of the stock standard. Commercially prepared stock 
standards can be used at any concentration if they are certified by the 
manufacturer or by an independent source.
    6.11.2  Transfer the stock standard solutions into Teflon-sealed 
screw-cap bottles. Store at 4  deg.C and protect from light. Stock 
standard solutions should be checked frequently for signs of degradation 
or evaporation, especially just prior to preparing calibration standards 
from them.
    6.11.3  Stock standard solutions must be replaced after six months, 
or sooner if comparison with check standards indicates a problem.
    6.12  Quality control check sample concentrate--See Section 8.2.1.

                             7. Calibration

    7.1  Establish gas chromatographic operating conditions equivalent 
to those given in Table 1. The gas chromatographic system can be 
calibrated using the external standard technique (Section 7.2) or the 
internal standard technique (Section 7.3).
    7.2  External standard calibration procedure:
    7.2.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask and diluting to volume 
with isooctane. One of the external standards should be at a 
concentration near, but above, the MDL (Table 1) and the other 
concentrations should correspond to the expected range of concentrations 
found in real samples or should define the working range of the 
detector.
    7.2.2  Using injections of 2 to 5 L, analyze each 
calibration standard according to Section 12 and tabulate peak height or 
area responses against the mass injected. The results can be used to 
prepare a calibration curve for each compound. Alternatively, if the 
ratio of response to amount injected (calibration factor) is a constant 
over the working range (<10% relative standard deviation, RSD), 
linearity through the origin can be assumed and the average ratio or 
calibration factor can be used in place of a calibration curve.
    7.3  Internal standard calibration procedure--To use this approach, 
the analyst must select one or more internal standards that are similar 
in analytical behavior to the compounds of interest. The analyst must 
further demonstrate that the measurement of the internal standard is not 
affected by method or matrix interferences. Because of these 
limitations, no internal standard can

[[Page 115]]

be suggested that is applicable to all samples.
    7.3.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask. To each calibration 
standard, add a known constant amount of one or more internal standards, 
and dilute to volume with isooctane. One of the standards should be at a 
concentration near, but above, the MDL and the other concentrations 
should correspond to the expected range of concentrations found in real 
samples or should define the working range of the detector.
    7.3.2  Using injections of 2 to 5 L, analyze each 
calibration standard according to Section 12 and tabulate peak height or 
area responses against concentration for each compound and internal 
standard. Calculate response factors (RF) for each compound using 
Equation 1.

                                                                                                                
                                                                         (As)(Cis)                              
                                                    RF             = -----------------                          
                                                                         (Ais)(Cs)                              
                                                                                                                

                                                              Equation 1
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Cis=Concentration of the internal standard (g/L).
    Cs=Concentraton of the parameter to be measured (g/L).

    If the RF value over the working range is a constant (< 10% RSD), 
the RF can be assumed to be invariant and the average RF can be used for 
calculations. Alternatively, the results can be used to plot a 
calibration curve of response ratios, As/Ais, vs. RF.
    7.4  The working calibration curve, calibration factor, or RF must 
be verified on each working day by the measurement of one or more 
calibration standards. If the response for any parameter varies from the 
predicted response by more than 15%, the test must be 
repeated using a fresh calibration standard. Alternatively, a new 
calibration curve must be prepared for that compound.
    7.5  The cleanup procedure in Section 11 utilizes Florisil column 
chromatography. Florisil from different batches or sources may vary in 
adsorptive capacity. To standardize the amount of Florisil which is 
used, the use of lauric acid value \9\ is suggested. The referenced 
procedure determines the adsorption from hexane solution of lauric acid 
(mg) per g of Florisil. The amount of Florisil to be used for each 
column is calculated by dividing 110 by this ratio and multiplying by 20 
g.
    7.6  Before using any cleanup procedure, the analyst must process a 
series of calibration standards through the procedure to validate 
elution patterns and the absence of interferences from the reagents.

                           8. Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality control program. The minimum requirements of this program 
consist of an initial demonstration of laboratory capability and an 
ongoing analysis of spiked samples to evaluate and document data 
quality. The laboratory must maintain records to document the quality of 
data that is generated. Ongoing data quality checks are compared with 
established performance criteria to determine if the results of analyses 
meet the performance characteristics of the method. When results of 
sample spikes indicate atypical method performance, a quality control 
check standard must be analyzed to confirm that the measurements were 
performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occurring in 
chromatography, the analyst is permitted certain options (detailed in 
Sections 10.4, 11.1, and 12.1) to improve the separations or lower the 
cost of measurements. Each time such a modification is made to the 
method, the analyst is required to repeat the procedure in Section 8.2.
    8.1.3  Before processing any samples, the analyst must analyze a 
reagent water blank to demonstrate that interferences from the 
analytical system and glassware are under control. Each time a set of 
samples is extracted or reagents are changed, a reagent water blank must 
be processed as a safeguard against laboratory contamination.
    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 10% of all samples to monitor and evaluate laboratory data 
quality. This procedure is described in Section 8.3.
    8.1.5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 10% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.5.

[[Page 116]]

    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality control (QC) check sample concentrate is required 
containing each single-component parameter of interest at the following 
concentrations in acetone: 4,4'-DDD, 10 g/mL; 4,4'-DDT, 10 
g/mL; endosulfan II, 10 g/mL; endosulfan sulfate, 10 
g/mL; endrin, 10 g/mL; any other single-component 
pesticide, 2 g/mL. If this method is only to be used to analyze 
for PCBs, chlordane, or toxaphene, the QC check sample concentrate 
should contain the most representative multicomponent parameter at a 
concentration of 50 g/mL in acetone. The QC check sample 
concentrate must be obtained from the U.S. Environmental Protection 
Agency, Environmental Monitoring and Support Laboratory in Cincinnati, 
Ohio, if available. If not available from that source, the QC check 
sample concentrate must be obtained from another external source. If not 
available from either source above, the QC check sample concentrate must 
be prepared by the laboratory using stock standards prepared 
independently from those used for calibration.
    8.2.2  Using a pipet, prepare QC check samples at the test 
concentrations shown in Table 3 by adding 1.00 mL of QC check sample 
concentrate to each of four 1-L aliquots of reagent water.
    8.2.3  Analyze the well-mixed QC check samples according to the 
method beginning in Section 10.
    8.2.4  Calculate the average recovery (X) in g/mL; and the 
standard deviation of the recovery (s) in g/mL, for each 
parameter using the four results.
    8.2.5  For each parameter compare s and X with the corresponding 
acceptance criteria for precision and accuracy, respectively, found in 
Table 3. If s and X for all parameters of interest meet the acceptance 
criteria, the system performance is acceptable and analysis of actual 
samples can begin. If any individual s exceeds the precision limit or 
any individual X falls outside the range for accuracy, the system 
performance is unacceptable for that parameter.

    Note: The large number of parameters in Table 3 present a 
substantial probability that one or more will fail at least one of the 
acceptance criteria when all parameters are analyzed.

    8.2.6  When one or more of the parameters tested fail at least one 
of the acceptance criteria, the analyst must proceed according to 
Section 8.2.6.1 or 8.2.6.2.
    8.2.6.1  Locate and correct the source of the problem and repeat the 
test for all parameters of interest beginning with Section 8.2.2.
    8.2.6.2  Beginning with Section 8.2.2, repeat the test only for 
those parameters that failed to meet criteria. Repeated failure, 
however, will confirm a general problem with the measurement system. If 
this occurs, locate and correct the source of the problem and repeat the 
test for all compmunds of interest beginning with Section 8.2.2.
    8.3  The laboratory must, on an ongoing basis, spike at least 10% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing one to ten samples per month, at least one 
spiked sample per month is required.
    8.3.1  The concentration of the spike in the sample should be 
determined as follows:
    8.3.1.1  If, as in compliance monitoring, the concentration of a 
specific parameter in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of a specific parameter in the sample 
is not being checked against a limit specific to that parameter, the 
spike should be at the test concentration in Section 8.2.2 or 1 to 5 
times higher than the background concentration determined in Section 
8.3.2, whichever concentration would be larger.
    8.3.1.3  If it is impractical to determine background levels before 
spiking (e.g., maximum holding times will be exceeded), the spike 
concentration should be (1) the regulatory concentration limit, if any; 
or, if none (2) the larger of either 5 times higher than the expected 
background concentration or the test concentration in Section 8.2.2.
    8.3.2  Analyze one sample aliquot to determine the background 
concentration (B) of each parameter. If necessary, prepare a new QC 
check sample concentrate (Section 8.2.1) appropriate for the background 
concentrations in the sample. Spike a second sample aliquot with 1.0 mL 
of the QC check sample concentrate and analyze it to determine the 
concentration after spiking (A) of each parameter. Calculate each 
percent recovery (P) as 100(A-B)%/T, where T is the known true value of 
the spike.
    8.3.3  Compare the percent recovery (P) for each parameter with the 
corresponding QC acceptance criteria found in Table 3. These acceptance 
criteria were calculated to include an allowance for error in 
measurement of both the background and spike concentrations, assuming a 
spike to background ratio of 5:1. This error will be accounted for to 
the extent that the analyst's spike to background ratio approaches 
5:1.\10\ If spiking was performed at a concentration lower than the test 
concentration in Section 8.2.2, the analyst must use either the QC 
acceptance criteria in Table 3, or optional QC acceptance criteria 
calculated for the specific spike concentration. To calculate optional 
acceptance criteria for the recovery of a parameter: (1)

[[Page 117]]

Calculate accuracy (X') using the equation in Table 4, substituting the 
spike concentration (T) for C; (2) calculate overall precision (S') 
using the equation in Table 4, substituting X' for X; (3) calculate the 
range for recovery at the spike concentration as (100 X'/
T)2.44(100 S'/T)%.\10\
    8.3.4  If any individual P falls outside the designated range for 
recovery, that parameter has failed the acceptance criteria. A check 
standard containing each parameter that failed the criteria must be 
analyzed as described in Section 8.4.
    8.4  If any parameter fails the acceptance criteria for recovery in 
Section 8.3, a QC check standard containing each parameter that failed 
must be prepared and analyzed.

    Note: The frequency for the required analysis of a QC check standard 
will depend upon the number of parameters being simultaneously tested, 
the complexity of the sample matrix, and the performance of the 
laboratory. If the entire list of parameters in Table 3 must be measured 
in the sample in Section 8.3, the probability that the analysis of a QC 
check standard will be required is high. In this case the QC check 
standard should be routinely analyzed with the spike sample.

    8.4.1  Prepare the QC check standard by adding 1.0 mL of QC check 
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The 
QC check standard needs only to contain the parameters that failed 
criteria in the test in Section 8.3.
    8.4.2  Analyze the QC check standards to determine the concentration 
measured (A) of each parameter. Calculate each percent recovery 
(Ps) as 100 (A/T)%, where T is the true value of the standard 
concentration.
    8.4.3  Compare the percent recovery (Ps) for each parameter 
with the corresponding QC acceptance criteria found in Table 3. Only 
parameters that failed the test in Section 8.3 need to be compared with 
these criteria. If the recovery of any such parameter falls outside the 
designated range, the laboratory performance for that parameter is 
judged to be out of control, and the problem must be immediately 
identified and corrected. The analytical result for that parameter in 
the unspiked sample is suspect and may not be reported for regulatory 
compliance purposes.
    8.5  As part of the QC program for the laboratory, method accuracy 
for wastewater samples must be assessed and records must be maintained. 
After the analysis of five spiked wastewater samples as in Section 8.3, 
calculate the average percent recovery (P) and the standard deviation of 
the percent recovery (sp). Express the accuracy assessment as a 
percent recovery interval from P-2 sp to P+2 sp. If P=90% and 
sp=10%, for example, the accuracy interval is expressed as 70-110%. 
Update the accuracy assessment for each parameter on a regular basis 
(e.g. after each five to ten new accuracy measurements).
    8.6  It is recommended that the laboratory adopt additional quality 
assurance practices for use with this method. The specific practices 
that are most productive depend upon the needs of the laboratory and the 
nature of the samples. Field duplicates may be analyzed to assess the 
precision of the environmental measurements. When doubt exists over the 
identification of a peak on the chromatogram, confirmatory techniques 
such as gas chromatography with a dissimilar column, specific element 
detector, or mass spectrometer must be used. Whenever possible, the 
laboratory should analyze standard reference materials and participate 
in relevant performance evaluation studies.

            9. Sample Collection, Preservation, and Handling

    9.1  Grab samples must be collected in glass containers. 
Conventional sampling practices \11\ should be followed, except that the 
bottle must not be prerinsed with sample before collection. Composite 
samples should be collected in refrigerated glass containers in 
accordance with the requirements of the program. Automatic sampling 
equipment must be as free as possible of Tygon tubing and other 
potential sources of contamination.
    9.2  All samples must be iced or refrigerated at 4  deg.C from the 
time of collection until extraction. If the samples will not be 
extracted within 72 h of collection, the sample should be adjusted to a 
pH range of 5.0 to 9.0 with sodium hydroxide solution or sulfuric acid. 
Record the volume of acid or base used. If aldrin is to be determined, 
add sodium thiosulfate when residual chlorine is present. EPA Methods 
330.4 and 330.5 may be used for measurement of residual chlorine.\12\ 
Field test kits are available for this purpose.
    9.3  All samples must be extracted within 7 days of collection and 
completely analyzed within 40 days of extraction.\2\

                          10. Sample Extraction

    10.1  Mark the water meniscus on the side of the sample bottle for 
later determination of sample volume. Pour the entire sample into a 2-L 
separatory funnel.
    10.2  Add 60 mL of methylene chloride to the sample bottle, seal, 
and shake 30 s to rinse the inner surface. Transfer the solvent to the 
separatory funnel and extract the sample by shaking the funnel for 2 
min. with periodic venting to release excess pressure. Allow the organic 
layer to separate from the water phase for a minimum of 10 min. If the 
emulsion interface between layers is more than one-third the volume of 
the solvent layer, the analyst must employ mechanical techniques to 
complete the phase separation.

[[Page 118]]

The optium technique depends upon the sample, but may include stirring, 
filtration of the emulsion through glass wool, centrifugation, or other 
physical methods. Collect the methylene chloride extract in a 250-mL 
Erlenmeyer flask.
    10.3  Add a second 60-mL volume of methylene chloride to the sample 
bottle and repeat the extraction procedure a second time, combining the 
extracts in the Erlenmeyer flask. Perform a third extraction in the same 
manner.
    10.4  Assemble a Kuderna-Danish (K-D) concentrator by attaching a 
10-mL concentrator tube to a 500-mL evaporative flask. Other 
concentration devices or techniques may be used in place of the K-D 
concentrator if the requirements of Section 8.2 are met.
    10.5  Pour the combined extract through a solvent-rinsed drying 
column containing about 10 cm of anhydrous sodium sulfate, and collect 
the extract in the K-D concentrator. Rinse the Erlenmeyer flask and 
column with 20 to 30 mL of methylene chloride to complete the 
quantitative transfer.
    10.6  Add one or two clean boiling chips to the evaporative flask 
and attach a three-ball Snyder column. Prewet the Snyder column by 
adding about 1 mL of methylene chloride to the top. Place the K-D 
apparatus on a hot water bath (60 to 65  deg.C) so that the concentrator 
tube is partially immersed in the hot water, and the entire lower 
rounded surface of the flask is bathed with hot vapor. Adjust the 
vertical position of the apparatus and the water temperature as required 
to complete the concentration in 15 to 20 min. At the proper rate of 
distillation the balls of the column will actively chatter but the 
chambers will not flood with condensed solvent. When the apparent volume 
of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain 
and cool for at least 10 min.
    10.7  Increase the temperature of the hot water bath to about 80 
deg.C. Momeltarily remove the Snyder column, add 50 mL of hexane and a 
new boiling chip, and reattach the Snyder column. Concentrate the 
extract as in Section 10.6, except use hexane to prewet the column. The 
elapsed time of concentration should be 5 to 10 min.
    10.8  Remove the Snyder column and rinse the flask and its lower 
joint into the concentrator tube with 1 to 2 mL of hexane. A 5-mL 
syringe is recommended for this operation. Stopper the concentrator tube 
and store refrigerated if further processing will not be performed 
immediately. If the extract will be stored longer than two days, it 
should be transferred to a Teflon-sealed screw-cap vial. If the sample 
extract requires no further cleanup, proceed with gas chromatographic 
analysis (Section 12). If the sample requires further cleanup, proceed 
to Section 11.
    10.9  Determine the original sample volume by refilling the sample 
bottle to the mark and transferring the liquid to a 1000-mL graduated 
cylinder. Record the sample volume to the nearest 5 mL.

                       11. Cleanup and Separation

    11.1  Cleanup procedures may not be necessary for a relatively clean 
sample matrix. If particular circumstances demand the use of a cleanup 
procedure, the analyst may use either procedure below or any other 
appropriate procedure. However, the analyst first must demonstrate that 
the requirements of Section 8.2 can be met using the method as revised 
to incorporate the cleanup procedure. The Florisil column allows for a 
select fractionation of the compounds and will eliminate polar 
interferences. Elemental sulfur, which interferes with the electron 
capture gas chromatography of certain pesticides, can be removed by the 
technique described in Section 11.3.
    11.2  Florisil column cleanup:
    11.2.1  Place a weight of Florisil (nominally 20 g) predetermined by 
calibration (Section 7.5), into a chromatographic column. Tap the column 
to settle the Florisil and add 1 to 2 cm of anhydrous sodium sulfate to 
the top.
    11.2.2  Add 60 mL of hexane to wet and rinse the sodium sulfate and 
Florisil. Just prior to exposure of the sodium sulfate layer to the air, 
stop the elution of the hexane by closing the stopcock on the 
chromatographic column. Discard the eluate.
    11.2.3  Adjust the sample extract volume to 10 mL with hexane and 
transfer it from the K-D concentrator tube onto the column. Rinse the 
tube twice with 1 to 2 mL of hexane, adding each rinse to the column.
    11.2.4  Place a 500-mL K-D flask and clean concentrator tube under 
the chromatographic column. Drain the column into the flask until the 
sodium sulfate layer is nearly exposed. Elute the column with 200 mL of 
6% ethyl ether in hexane (V/V) (Fraction 1) at a rate of about 5 mL/min. 
Remove the K-D flask and set it aside for later concentration. Elute the 
column again, using 200 mL of 15% ethyl ether in hexane (V/V) (Fraction 
2), into a second K-D flask. Perform the third elution using 200 mL of 
50% ethyl ether in hexane (V/V) (Fraction 3). The elution patterns for 
the pesticides and PCBs are shown in Table 2.
    11.2.5  Concentrate the fractions as in Section 10.6, except use 
hexane to prewet the column and set the water bath at about 85  deg.C. 
When the apparatus is cool, remove the Snyder column and rinse the flask 
and its lower joint into the concentrator tube with hexane. Adjust the 
volume of each fraction to 10 mL with hexane and analyze by gas 
chromatography (Section 12).
    11.3  Elemental sulfur will usually elute entirely in Fraction 1 of 
the Florisil column

[[Page 119]]

cleanup. To remove sulfur interference from this fraction or the 
original extract, pipet 1.00 mL of the concentrated extract into a clean 
concentrator tube or Teflon-sealed vial. Add one to three drops of 
mercury and seal.\13\ Agitate the contents of the vial for 15 to 30 s. 
Prolonged shaking (2 h) may be required. If so, this may be accomplished 
with a reciprocal shaker. Alternatively, activated copper powder may be 
used for sulfur removal.\14\ Analyze by gas chromatography.

                         12. Gas Chromatography

    12.1  Table 1 summarizes the recommended operating conditions for 
the gas chromatograph. Included in this table are retention times and 
MDL that can be achieved under these conditions. Examples of the 
separations achieved by Column 1 are shown in Figures 1 to 10. Other 
packed or capillary (open-tubular) columns, chromatographic conditions, 
or detectors may be used if the requirements of Section 8.2 are met.
    12.2  Calibrate the system daily as described in Section 7.
    12.3  If the internal standard calibration procedure is being used, 
the internal standard must be added to the sample extract and mixed 
thoroughly immediately before injection into the gas chromatograph.
    12.4  Inject 2 to 5 L of the sample extract or standard 
into the gas chromatograph using the solvent-flush technique.\15\ 
Smaller (1.0 uL) volumes may be injected if automatic devices are 
employed. Record the volume injected to the nearest 0.05 L, the 
total extract volume, and the resulting peak size in area or peak height 
units.
    12.5  Identify the parameters in the sample by comparing the 
retention times of the peaks in the sample chromatogram with those of 
the peaks in standard chromatograms. The width of the retention time 
window used to make identifications should be based upon measurements of 
actual retention time variations of standards over the course of a day. 
Three times the standard deviation of a retention time for a compound 
can be used to calculate a suggested window size; however, the 
experience of the analyst should weigh heavily in the interpretation of 
chromatograms.
    12.6  If the response for a peak exceeds the working range of the 
system, dilute the extract and reanalyze.
    12.7  If the measurement of the peak response is prevented by the 
presence of interferences, further cleanup is required.

                            13. Calculations

    13.1  Determine the concentration of individual compounds in the 
sample.
    13.1.1  If the external standard calibration procedure is used, 
calculate the amount of material injected from the peak response using 
the calibration curve or calibration factor determined in Section 7.2.2. 
The concentration in the sample can be calculated from Equation 2.

                                                                                                                
                                                                           (A)(Vt)                              
                                        Concentration (g/  = -----------------                         
                                                    L)                     (Vi)(Vs)                             
                                                                                                                

                                                              Equation 2
where:
    A=Amount of material injected (ng).
    Vi=Volume of extract injected (L).
    Vt=Volume of total extract (L).
    Vs=Volume of water extracted (mL).

    13.1.2  If the internal standard calibration procedure is used, 
calculate the concentration in the sample using the response factor (RF) 
determined in Section 7.3.2 and Equation 3.

                                                                                                                
                                                                           (As)(Is)                             
                                        Concentration (g/  = -----------------                         
                                                    L)                  (Ais)(RF)(Vo)                           
                                                                                                                

                                                              Equation 3
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Is=Amount of internal standard added to each extract 
(g).
    Vo=Volume of water extracted (L).
    13.2  When it is apparent that two or more PCB (Aroclor) mixtures 
are present, the Webb and McCall procedure \16\ may be used to identify 
and quantify the Aroclors.
    13.3  For multicomponent mixtures (chlordane, toxaphene, and PCBs) 
match retention times of peaks in the standards with peaks in the 
sample. Quantitate every identifiable peak unless interference with 
individual peaks persist after cleanup. Add peak height or peak area of 
each identified peak in the chromatogram. Calculate as total response in 
the sample versus total response in the standard.
    13.4  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

                         14. Method Performance

    14.1  The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the value is above zero.\1\ The MDL concentrations 
listed in Table 1 were obtained using reagent water.\17\ Similar results 
were achieved using representative wastewaters. The MDL actually 
achieved in a given analysis will vary depending on instrument 
sensitivity and matrix effects.
    14.2  This method has been tested for linearity of spike recovery 
from reagent water and has been demonstrated to be applicable

[[Page 120]]

over the concentration range from 4 x MDL to 1000 x MDL with the 
following exceptions: Chlordane recovery at 4 x MDL was low (60%); 
Toxaphene recovery was demonstrated linear over the range of 10 x MDL to 
1000 x MDL.\17\
    14.3  This method was tested by 20 laboratories using reagent water, 
drinking water, surface water, and three industrial wastewaters spiked 
at six concentrations.\18\ Concentrations used in the study ranged from 
0.5 to 30 g/L for single-component pesticides and from 8.5 to 
400 g/L for multicomponent parameters. Single operator 
precision, overall precision, and method accuracy were found to be 
directly related to the concentration of the parameter and essentially 
independent of the sample matrix. Linear equations to describe these 
relationships are presented in Table 4.

                               References

    1. 40 CFR part 136, appendix B.
    2. ``Determination of Pesticides and PCBs in Industrial and 
Municipal Wastewaters,'' EPA 600/4-82-023, National Technical 
Information Service, PB82-214222, Springfield, Virginia 22161, April 
1982.
    3. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard 
Practices for Preparation of Sample Containers and for Preservation of 
Organic Constituents,'' American Society for Testing and Materials, 
Philadelphia.
    4. Giam, C.S., Chan, H.S., and Nef, G.S., ``Sensitive Method for 
Determination of Phthalate Ester Plasticizers in Open-Ocean Biota 
Samples,'' Analytical Chemistry, 47, 2225 (1975).
    5. Giam, C.S., Chan, H.S. ``Control of Blanks in the Analysis of 
Phthalates in Air and Ocean Biota Samples,'' U.S. National Bureau of 
Standards, Special Publication 442, pp. 701-708, 1976.
    6. ``Carcinogens--Working With Carcinogens,'' Department of Health, 
Education, and Welfare, Public Health Service, Center for Disease 
Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    7. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR 
part 1910), Occupational Safety and Health Administration, OSHA 2206 
(Revised, January 1976).
    8. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    9. Mills, P.A. ``Variation of Florisil Activity: Simple Method for 
Measuring Absorbent Capacity and Its Use in Standardizing Florisil 
Columns,'' Journal of the Association of Official Analytical Chemists, 
51, 29, (1968).
    10. Provost, L.P., and Elder, R.S. ``Interpretation of Percent 
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44 
used in the equation in Section 8.3.3 is two times the value 1.22 
derived in this report.)
    11. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard 
Practices for Sampling Water,'' American Society for Testing and 
Materials, Philadelphia.
    12. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for 
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory, Cincinnati, Ohio 45268, March 1979.
    13. Goerlitz, D.F., and Law, L.M. Bulletin for Environmental 
Contamination and Toxicology, 6, 9 (1971).
    14. ``Manual of Analytical Methods for the Analysis of Pesticides in 
Human and Environmental Samples,'' EPA-600/8-80-038, U.S. Environmental 
Protection Agency, Health Effects Research Laboratory, Research Triangle 
Park, North Carolina.
    15. Burke, J.A. ``Gas Chromatography for Pesticide Residue Analysis; 
Some Practical Aspects,'' Journal of the Association of Official 
Analytical Chemists, 48, 1037 (1965).
    16. Webb, R.G., and McCall, A.C. ``Quantitative PCB Standards for 
Election Capture Gas Chromatography,'' Journal of Chromatographic 
Science, 11, 366 (1973).
    17. ``Method Detection Limit and Analytical Curve Studies, EPA 
Methods 606, 607, and 608,'' Special letter report for EPA Contract 68-
03-2606, U.S. Environmental Protection Agency, Environmental Monitoring 
and Support Laboratory, Cincinnati, Ohio 45268, June 1980.
    18. ``EPA Method Study 18 Method 608--Organochlorine Pesticides and 
PCBs,'' EPA 600/4-84-061, National Technical Information Service, PB84-
211358, Springfield, Virginia 22161, June 1984.

     Table 1--Chromatographic Conditions and Method Detection Limits    
------------------------------------------------------------------------
                                          Retention time       Method   
                                               (min)          detection 
               Parameter               --------------------     limit   
                                                            (g/
                                         Col. 1    Col. 2        L)     
------------------------------------------------------------------------
-BHC.........................      1.35      1.82       0.003  
-BHC.........................      1.70      2.13       0.004  
-BHC.........................      1.90      1.97       0.006  
Heptachlor............................      2.00      3.35       0.003  
-BHC.........................      2.15      2.20       0.009  
Aldrin................................      2.40      4.10       0.004  
Heptachlor epoxide....................      3.50      5.00       0.083  
Endosulfan I..........................      4.50      6.20       0.014  
4,4-DDE...............................      5.13      7.15       0.004  
Dieldrin..............................      5.45      7.23       0.002  
Endrin................................      6.55      8.10       0.006  
4,4-DDD...............................      7.83      9.08       0.011  
Endosulfan II.........................      8.00      8.28       0.004  
4,4-DDT...............................      9.40     11.75       0.012  
Endrin aldehyde.......................     11.82      9.30       0.023  
Endosulfan sulfate....................     14.22     10.70       0.066  
Chlordane.............................     mr        mr          0.014  
Toxaphene.............................     mr        mr          0.24   

[[Page 121]]

                                                                        
PCB-1016..............................     mr        mr         nd      
PCB-1221..............................     mr        mr         nd      
PCB-1232..............................     mt        mr         nd      
PCB-1242..............................     mr        mr          0.065  
PCB-1248..............................     mr        mr         nd      
PCB-1254..............................     mr        mr         nd      
PCB-1260..............................     mr        mr         nd      
------------------------------------------------------------------------
 AColumn 1 conditions: Supelcoport (100/120 mesh) coated with 1.5% SP-  
  2250/1.95% SP-2401 packed in a 1.8 m long  x  4 mm ID glass column    
  with 5% methane/95% argon carrier gas at 60 mL/min flow rate. Column  
  temperature held isothermal at 200 C, except for PCB-1016 through PCB-
  1248, should be measured at 160 C.                                    
 AColumn 2 conditions: Supelcoport (100/120 mesh) coated with 3% OV-1   
  packed in a 1.8 m long  x  4 mm ID glass column with 5% methane/95%   
  argon carrier gas at 60 mL/min flow rate. Column temperature held     
  isothermal at 200 C for the pesticides; at 140 C for PCB-1221 and     
  1232; and at 170 C for PCB-1016 and 1242 to 1268.                     
 Amr=Multiple peak response. See Figures 2 thru 10.                     
 And=Not determined.                                                    


 Table 2--Distribution of Chlorinated Pesticides and PCBs into Florisil 
                          Column Fractions \2\                          
------------------------------------------------------------------------
                                          Percent recovery by fraction a
               Parameter                --------------------------------
                                             1          2          3    
------------------------------------------------------------------------
Aldrin.................................        100  .........  .........
-BHC..........................        100  .........  .........
-BHC..........................         97  .........  .........
-BHC..........................         98  .........  .........
-BHC..........................        100  .........  .........
Chlordane..............................        100  .........  .........
4,4-DDD................................         99  .........  .........
4,4-DDE................................         98  .........  .........
4,4-DDT................................        100  .........  .........
Dieldrin...............................          0        100  .........
Endosulfan I...........................         37         64  .........
Endosulfan II..........................          0          7         91
Endosulfan sulfate.....................          0          0        106
Endrin.................................          4         96  .........
Endrin aldehyde........................          0         68         26
Heptachlor.............................        100  .........  .........
Heptachlor epoxide.....................        100  .........  .........
Toxaphene..............................         96  .........  .........
PCB-1016...............................         97  .........  .........
PCB-1221...............................         97  .........  .........
PCB-1232...............................         95          4  .........
PCB-1242...............................         97  .........  .........
PCB-1248...............................        103  .........  .........
PCB-1254...............................         90  .........  .........
PCB-1260...............................         95  .........  .........
------------------------------------------------------------------------
a Eluant composition:                                                   
    Fraction 1-6% ethyl ether in hexane.                                
    Fraction 2-15% ethyl ether in hexane.                               
    Fraction 3-50% ethyl ether in hexane.                               


                                   Table 3--QC Acceptance Criteria--Method 608                                  
----------------------------------------------------------------------------------------------------------------
                                                                                           Range for X          
                                                               Test conc.    Limit for s  (g/    Range 
                          Parameter                           (g/  (g/       L)        for P, 
                                                                   L)            L)                       Ps(%) 
----------------------------------------------------------------------------------------------------------------
Aldrin......................................................        2.0           0.42    1.08-2.24       42-122
-BHC...............................................        2.0           0.48    0.98-2.44       37-134
-BHC...............................................        2.0           0.64    0.78-2.60       17-147
-BHC...............................................        2.0           0.72    1.01-2.37       19-140
-BHC...............................................        2.0           0.46    0.86-2.32       32-127
Chlordane...................................................       50            10.0     27.6-54.3       45-119
4,4 -DDD....................................................       10             2.8     4.8-12.6        31-141
4,4 -DDE....................................................        2.0           0.55    1.08-2.60       30-145
4,4-DDT.....................................................       10             3.6     4.6-13.7        25-160
Dieldrin....................................................        2.0           0.76    1.15-2.49       36-146
Endosulfan I................................................        2.0           0.49    1.14-2.82       45-153
Endosulfan II...............................................       10             6.1     2.2-17.1         D-202
Endosulfan Sulfate..........................................       10             2.7     3.8-13.2        26-144
Endrin......................................................       10             3.7     5.1-12.6        30-147
Heptachlor..................................................        2.0           0.40    0.86-2.00       34-111
Heptachlor epoxide..........................................        2.0           0.41    1.13-2.63       37-142
Toxaphene...................................................       50.0          12.7     27.8-55.6       41-126
PCB-1016....................................................       50            10.0     30.5-51.5       50-114
PCB-1221....................................................       50            24.4     22.1-75.2       15-178
PCB-1232....................................................       50            17.9     14.0-98.5       10-215
PCB-1242....................................................       50            12.2     24.8-69.6       39-150
PCB-1248....................................................       50            15.9     29.0-70.2       38-158
PCB-1254....................................................       50            13.8     22.2-57.9       29-131
PCB-1260....................................................       50            10.4     18.7-54.9        8-127
----------------------------------------------------------------------------------------------------------------
s=Standard deviation of four recovery measurements, in g/L (Section 8.2.4).                            
X=Average recovery for four recovery measurements, in g/L (Section 8.2.4).                             
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).                                                 
D=Detected; result must be greater than zero.                                                                   
                                                                                                                
Note: These criteria are based directly upon the method performance data in Table 4. Where necessary, the limits
  for recovery have been broadened to assure applicability of the limits to concentrations below those used to  
  develop Table 4.                                                                                              


                Table 4--Method Accuracy and Precision as Functions of Concentration--Method 608                
----------------------------------------------------------------------------------------------------------------
                                                         Accuracy, as       Single analyst                      
                      Parameter                           recovery, X        precision, sr    Overall precision,
                                                        (g/L)      (g/L)     S (g/L) 
----------------------------------------------------------------------------------------------------------------
Aldrin..............................................          0.81C+0.04          0.16X-0.04          0.20X-0.01
-BHC.......................................          0.84C+0.03          0.13X+0.04          0.23X-0.00
-BHC.......................................          0.81C+0.07          0.22X-0.02          0.33X-0.05
-BHC.......................................          0.81C+0.07          0.18X+0.09          0.25X+0.03
-BHC.......................................          0.82C-0.05          0.12X+0.06          0.22X+0.04
Chlordane...........................................          0.82C-0.04          0.13X+0.13          0.18X+0.18
4,4-DDD.............................................          0.84C+0.30          0.20X-0.18          0.27X-0.14
4,4-DDE.............................................          0.85C+0.14          0.13X+0.06          0.28X-0.09
4,4-DDT.............................................          0.93C-0.13          0.17X+0.39          0.31X-0.21
Dieldrin............................................          0.90C+0.02          0.12X+0.19          0.16X+0.16

[[Page 122]]

                                                                                                                
Endosulfan I........................................          0.97C+0.04          0.10X+0.07          0.18X+0.08
Endosulfan II.......................................          0.93C+0.34         0.41X--0.65          0.47X-0.20
Endosulfan Sulfate..................................          0.89C-0.37          0.13X+0.33          0.24X+0.35
Endrin..............................................          0.89C-0.04          0.20X+0.25          0.24X+0.25
Heptachlor..........................................          0.69C+0.04          0.06X+0.13          0.16X+0.08
Heptachlor epoxide..................................          0.89C+0.10          0.18X-0.11          0.25X-0.08
Toxaphene...........................................          0.80C+1.74          0.09X+3.20          0.20X+0.22
PCB-1016............................................          0.81C+0.50          0.13X+0.15          0.15X+0.45
PCB-1221............................................          0.96C+0.65          0.29X-0.76          0.35X-0.62
PCB-1232............................................         0.91C+10.79          0.21X-1.93          0.31X+3.50
PCB-1242............................................          0.93C+0.70          0.11X+1.40          0.21X+1.52
PCB-1248............................................          0.97C+1.06          0.17X+0.41          0.25X-0.37
PCB-1254............................................          0.76C+2.07          0.15X+1.66          0.17X+3.62
PCB-1260............................................          0.66C+3.76          0.22X-2.37          0.39X-4.86
----------------------------------------------------------------------------------------------------------------
X=Expected recovery for one or more measurements of a sample containing a concentration of C, in g/L.  
sr=Expected single analyst standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
S=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
C=True value for the concentration, in g/L.                                                            
X=Average recovery found for measurements of samples containing a concentration of C, in g/L.          


[[Page 123]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.019


[[Page 124]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.020


[[Page 125]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.021


[[Page 126]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.022


[[Page 127]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.023


[[Page 128]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.024


[[Page 129]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.025


[[Page 130]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.026


[[Page 131]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.027


[[Page 132]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.028


[[Page 133]]

                Method 609--Nitroaromatics and Isophorone

                        1. Scope and Application

    1.1  This method covers the determination of certain nitroaromatics 
and isophorone. The following parameters may be determined by this 
method:

------------------------------------------------------------------------
                   Parameter                     STORET No.    CAS No.  
------------------------------------------------------------------------
2,4-Dinitrotoluene............................        34611     121-14-2
2,6-Dinitrotoluene............................        34626     606-20-2
Isophorone....................................        34408      78-59-1
Nitrobenzene..................................        34447      98-95-3
------------------------------------------------------------------------

    1.2  This is a gas chromatographic (GC) method applicable to the 
determination of the compounds listed above in municipal and industrial 
discharges as provided under 40 CFR 136.1. When this method is used to 
analyze unfamiliar samples for any or all of the compounds above, 
compound identifications should be supported by at least one additional 
qualitative technique. This method describes analytical conditions for a 
second gas chromatographic column that can be used to confirm 
measurements made with the primary column. Method 625 provides gas 
chromatograph/mass spectrometer (GC/MS) conditions appropriate for the 
qualitative and quantitative confirmation of results for all of the 
parameters listed above, using the extract produced by this method.
    1.3  The method detection limit (MDL, defined in Section 14.1)\1\ 
for each parameter is listed in Table 1. The MDL for a specific 
wastewater may differ from those listed, depending upon the nature of 
interferences in the sample matrix.
    1.4  The sample extraction and concentration steps in this method 
are essentially the same as in Methods 606, 608, 611, and 612. Thus, a 
single sample may be extracted to measure the parameters included in the 
scope of each of these methods. When cleanup is required, the 
concentration levels must be high enough to permit selecting aliquots, 
as necessary, to apply appropriate cleanup procedures. The analyst is 
allowed the latitude, under Section 12, to select chromatographic 
conditions appropriate for the simultaneous measurement of combinations 
of these parameters.
    1.5  Any modification of this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5.
    1.6  This method is restricted to use by or under the supervision of 
analysts experienced in the use of a gas chromatograph and in the 
interpretation of gas chromatograms. Each analyst must demonstrate the 
ability to generate acceptable results with this method using the 
procedure described in Section 8.2.

                          2. Summary of Method

    2.1  A measured volume of sample, approximately 1-L, is extracted 
with methylene chloride using a separatory funnel. The methylene 
chloride extract is dried and exchanged to hexane during concentration 
to a volume of 10 mL or less. Isophorone and nitrobenzene are measured 
by flame ionization detector gas chromatography (FIDGC). The 
dinitrotoluenes are measured by electron capture detector gas 
chromatography (ECDGC).\2\
    2.2  The method provides a Florisil column cleanup procedure to aid 
in the elimination of interferences that may be encountered.

                            3. Interferences

    3.1  Method interferences may be caused by contaminants in solvents, 
reagents, glassware, and other sample processing hardware that lead to 
discrete artifacts and/or elevated baseliles in gas chromatograms. All 
of these materials must be routinely demonstrated to be free from 
interferences under the conditions of the analysis by running laboratory 
reagent blanks as described in Section 8.1.3.
    3.1.1  Glassware must be scrupulously cleaned.\3\ Clean all 
glassware as soon as possible after use by rinsing with the last solvent 
used in it. Solvent rinsing should be followed by detergent washing with 
hot water, and rinses with tap water and distilled water. The glassware 
should then be drained dry, and heated in a muffle furnace at 400  deg.C 
for 15 to 30 min. Some thermally stable materials, such as PCBs, may not 
be eliminated by this treatment. Solvent rinses with acetone and 
pesticide quality hexane may be substituted for the muffle furnace 
heating. Thorough rinsing with such solvents usually eliminates PCB 
interference. Volumetric ware should not be heated in a muffle furnace. 
After drying and cooling, glassware should be sealed and stored in a 
clean environment to prevent any accumulation of dust or other 
contaminants. Store inverted or capped with aluminum foil.
    3.1.2  The use of high purity reagents and solvents helps to 
minimize interference problems. Purification of solvents by distillation 
in all-glass systems may be required.
    3.2  Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary 
considerably from source to source, depending upon the nature and 
diversity of the industrial complex or municipality being sampled. The 
cleanup procedure in Section 11 can be used to overcome many of these 
interferences, but unique samples may require additional cleanup 
approaches to achieve the MDL listed in Table 1.

[[Page 134]]

                                4. Safety

    4.1  The toxicity or carcinogenicity of each reagent used in this 
method has not been precisely defined; however, each chemical compound 
should be treated as a potential health hazard. From this viewpoint, 
exposure to these chemicals must be reduced to the lowest possible level 
by whatever means available. The laboratory is responsible for 
maintaining a current awareness file of OSHA regulations regarding the 
safe handling of the chemicals specified in this method. A reference 
file of material data handling sheets should also be made available to 
all personnel involved in the chemical analysis. Additional references 
to laboratory safety are available and have been identified \4\-\6\ 
for the information of the analyst.

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete or composite sampling.
    5.1.1  Grab sample bottle--1-L or 1-qt, amber glass, fitted with a 
screw cap lined with Teflon. Foil may be substituted for Teflon if the 
sample is not corrosive. If amber bottles are not available, protect 
samples from light. The bottle and cap liner must be washed, rinsed with 
acetone or methylene chloride, and dried before use to minimize 
contamination.
    5.1.2  Automatic sampler (optional)--The sampler must incorporate 
glass sample containers for the collection of a minimum of 250 mL of 
sample. Sample containers must be kept refrigerated at 4  deg.C and 
protected from light during compositing. If the sampler uses a 
peristaltic pump, a minimum length of compressible silicone rubber 
tubing may be used. Before use, however, the compressible tubing should 
be thoroughly rinsed with methanol, followed by repeated rinsings with 
distilled water to minimize the potential for contamination of the 
sample. An integrating flow meter is required to collect flow 
proportional composites.
    5.2  Glassware (All specifications are suggested. Catalog numbers 
are included for illustration only.):
    5.2.1  Separatory funnel--2-L, with Teflon stopcock.
    5.2.2  Drying column--Chromatographic column, approximately 400 mm 
long x 19 mm ID, with coarse frit filter disc.
    5.2.3  Chromatographic column--100 mm long x 10 mm ID, with Teflon 
stopcock.
    5.2.4  Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes 
K-570050-1025 or equivalent). Calibration must be checked at the volumes 
employed in the test. Ground glass stopper is used to prevent 
evaporation of extracts.
    5.2.5  Evaporative flask, Kuderna-Danish--500-mL (Kontes K-570001-
0500 or equivalent). Attach to concentrator tube with springs.
    5.2.6  Snyder column, Kuderna-Danish--Three-ball macro (Kontes K-
503000-0121 or equivalent).
    5.2.7  Snyder column, Kuderna-Danish--Two-ball micro (Kontes K-
569001-0219 or equivalent).
    5.2.8  Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
    5.3  Boiling chips--Approximately 10/40 mesh. Heat to 400  deg.C for 
30 min or Soxhlet extract with methylene chloride.
    5.4  Water bath--Heated, with concentric ring cover, capable of 
temperature control ( 2  deg.C). The bath should be used in 
a hood.
    5.5  Balance--Analytical, capable of accurately weighing 0.0001 g.
    5.6  Gas chromatograph--An analytical system complete with gas 
chromatograph suitable for on-column injection and all required 
accessories including syringes, analytical columns, gases, detector, and 
strip-chart recorder. A data system is recommended for measuring peak 
areas.
    5.6.1  Column 1--1.2 m long x 2 or 4 mm ID glass, packed with 1.95% 
QF-1/1.5% OV-17 on Gas-Chrom Q (80/100 mesh) or equivalent. This column 
was used to develop the method performance statements given in Section 
14. Guidelines for the use of alternate column packings are provided in 
Section 12.1.
    5.6.2  Column 2--3.0 m long x 2 or 4 mm ID glass, packed with 3% OV-
101 on Gas-Chrom Q (80/100 mesh) or equivalent.
    5.6.3  Detectors--Flame ionization and electron capture detectors. 
The flame ionization detector (FID) is used when determining isophorone 
and nitrobenzene. The electron capture detector (ECD) is used when 
determining the dinitrotoluenes. Both detectors have proven effective in 
the analysis of wastewaters and were used in develop the method 
performance statements in Section 14. Guidelines for the use to 
alternate detectors are provided in Section 12.1.

                               6. Reagents

    6.1  Reagent water--Reagent water is defined as a water in which an 
interferent is not observed at the MDL of the parameters of interest.
    6.2  Sodium hydroxide solution (10 N)--Dissolve 40 g of NaOH (ACS) 
in reagent water and dilute to 100 mL.
    6.3  Sulfuric acid (1+1)--Slowly, add 50 mL of H2SO4 (ACS, 
sp. gr. 1.84) to 50 mL of reagent water.
    6.4  Acetone, hexane, methanol, methylene chloride--Pesticide 
quality or equivalent.
    6.5  Sodium sulfate--(ACS) Granular, anhydrous. Purify by heating at 
400  deg.C for 4 h in a shallow tray.
    6.6  Florisil--PR grade (60/100 mesh). Purchase activated at 1250 
deg.F and store in dark in glass containers with ground glass stoppers 
or foil-lined screw caps. Before use, activate each batch at least 16 h 
at 200  deg.C in a

[[Page 135]]

foil-covered glass container and allow to cool.
    6.7  Stock standard solutions (1.00 g/L)--Stock 
standard solutions can be prepared from pure standard materials or 
purchased as certified solutions.
    6.7.1  Prepare stock standard solutions by accurately weighing about 
0.0100 g of pure material. Dissolve the material in hexane and dilute to 
volume in a 10-mL volumetric flask. Larger volumes can be used at the 
convenience of the analyst. When compound purity is assayed to be 96% or 
greater, the weight can be used without correction to calculate the 
concentration of the stock standard. Commercially prepared stock 
standards can be used at any concentration if they are certified by the 
manufacturer or by an independent source.
    6.7.2  Transfer the stock standard solutions into Teflon-sealed 
screw-cap bottles. Store at 4  deg.C and protect from light. Stock 
standard solutions should be checked frequently for signs of degradation 
or evaporation, especially just prior to preparing calibration standards 
from them.
    6.7.3  Stock standard solutions must be replaced after six months, 
or sooner if comparison with check standards indicates a problem.
    6.8  Quality control check sample concentrate--See Section 8.2.1.

                             7. Calibration

    7.1  Establish gas chromatographic operating conditions equivalent 
to those given in Table 1. The gas chromatographic system can be 
calibrated using the external standard technique (Section 7.2) or the 
internal standard technique (Section 7.3).
    7.2  External standard calibration procedure:
    7.2.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask and diluting to volume 
with hexane. One of the external standards should be at a concentration 
near, but above, the MDL (Table 1) and the other concentrations should 
correspond to the expected range of concentrations found in real samples 
or should define the working range of the detector.
    7.2.2  Using injections of 2 to 5 L, analyze each 
calibration standard according to Section 12 and tabulate peak height or 
area responses against the mass injected. The results can be used to 
prepare a calibration curve for each compound. Alternatively, if the 
ratio of response to amount injected (calibration factor) is a constant 
over the working range (< 10% relative standard deviation, RSD) 
linearity through the origin can be assumed and the average ratio or 
calibration factor can be used in place of a calibration curve.
    7.3  Internal standard calibration procedure--To use this approach, 
the analyst must select one or more internal standards that are similar 
in analytical behavior to the compounds of interest. The analyst must 
further demonstrate that the measurement of the internal standard is not 
affected by method or matrix interferences. Because of these 
limitations, no internal standard can be suggested that is applicable to 
all samples.
    7.3.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flash. To each calibration 
standard, add a known constant amount of one or more internal standards, 
and dilute to volume with hexane. One of the standards should be at a 
concentration near, but above, the MDL and the other concentrations 
should correspond to the expected range of concentrations found in real 
samples or should define the working range of the detector.
    7.3.2  Using injections of 2 to 5 L, analyze each 
calibration standard according to Section 12 and tabulate peak height or 
area responses against concentration for each compound and internal 
standard. Calculate response factors (RF) for each compound using 
Equation 1.
    Equation 1.

                                                                        
                                          (As)(Cis)                     
                                    RF=  -----------                    
                                          (Ais)(Cs)                     
                                                                        

where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Cis=Concentration of the internal standard (g/L).
    Cs=Concentration of the parameter to be measured (g/
L).

    If the RF value over the working range is a constant (< 10% RSD), 
the RF can be assumed to be invariant and the average RF can be used for 
calculations. Alternatively, the results can be used to plot a 
calibration curve of response ratios, As/Ais, vs. RF.
    7.4  The working calibration curve, calibration factor, or RF must 
be verified on each working day by the measurement of one or more 
calibration standards. If the response for any parameter varies from the 
predicted response by more than  15%, a new calibration 
curve must be prepared for that compound.
    7.5  Before using any cleanup procedure, the analyst must process a 
series of calibration standards through the procedure to validate 
elution patterns and the absence of interferences from the reagents.

[[Page 136]]

                           8. Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality control program. The minimum requirements of this program 
consist of an initial demonstration of laboratory capability and an 
ongoing analysis of spiked samples to evaluate and document data 
quality. The laboratory must maintain records to document the quality of 
data that is generated. Ongoing data quality checks are compared with 
established performance criteria to determine if the results of analyses 
meet the performance characteristics of the method. When results of 
sample spikes indicate atypical method performance, a quality control 
check standard must be analyzed to confirm that the measurements were 
performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occurring in 
chromatography, the analyst is permitted certain options (detailed in 
Sections 10.4, 11.1, and 12.1) to improve the separations or lower the 
cost of measurements. Each time such a modification is made to the 
method, the analyst is required to repeat the procedure in Section 8.2.
    8.1.3  Before processing any samples, the analyst must analyze a 
reagent water blank to demonstrate that interferences from the 
analytical system and glassware are under control. Each time a set of 
samples is extracted or reagents are changed, a reagent water blank must 
be processed as a safeguard against laboratory contamination.
    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 10% of all samples to monitor and evaluate laboratory data 
quality. This procedure is described in Section 8.3.
    8.1,5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 10% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.5.
    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality control (QC) check sample concentrate is required 
containing each parameter of interest in acetone at a concentration of 
20 g/mL for each dinitrotoluene and 100 g/mL for 
isophorone and nitrobenzene. The QC check sample concentrate must be 
obtained from the U.S. Environmental Protection Agency, Environmental 
Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If 
not available from that source, the QC check sample concentrate must be 
obtained from another external source. If not available from either 
source above, the QC check sample concentrate must be prepared by the 
laboratory using stock standards prepared independently from those used 
for calibration.
    8.2.2  Using a pipet, prepare QC check samples at the test 
concentrations shown in Table 2 by adding 1.00 mL of QC check sample 
concentrate to each of four 1-L aliquots of reagent water.
    8.2.3  Analyze the well-mixed QC check samples according to the 
method beginning in Section 10.
    8.2.4  Calculate the average recovery (X) in g/L, and the 
standard deviation of the recovery (s) in g/L, for each 
parameter using the four results.
    8.2.5  For each parameter compare s and X with the corresponding 
acceptance criteria for precision and accuracy, respectively, found in 
Table 2. If s and X for all parameters of interest meet the acceptance 
criteria, the system performance is acceptable and analysis of actual 
samples can begin. If any individual s exceeds the precision limit or 
any individual X falls outside the range for accuracy, the system 
performance is unacceptable for that parameter. Locate and correct the 
source of the problem and repeat the test for all parameters of interest 
beginning with Section 8.2.2.
    8.3  The laboratory must, on an ongoing basis, spike at least 10% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing one to ten samples per month, at least one 
spiked sample per month is required.
    8.3.1  The concentration of the spike in the sample should be 
determined as follows:
    8.3.1.1  If, as in compliance monitoring, the concentration of a 
specific parameter in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of a specific parameter in the sample 
is not being checked against a limit specific to that parameter, the 
spike should be at the test concentration in Section 8.2.2 or 1 to 5 
times higher than the background concentration determined in Section 
8.3.2, whichever concentration would be larger.
    8.3.1.3  If it is impractical to determile background levels before 
spiking (e.g., maximum holding times will be exceeded), the

[[Page 137]]

spike concentration should be (1) the regulatory concentration limit, if 
any; or, if none (2) the larger of either 5 times higher than the 
expected background concentration or the test concentration in Section 
8.2.2.
    8.3.2  Analyze one sample aliquot to determine the background 
concentration (B) of each parameter. If necessary, prepare a new QC 
check sample concentrate (Section 8.2.1) appropriate for the background 
concentrations in the sample. Spike a second sample aliquot with 1.0 mL 
of the QC check sample concentrate and analyze it to determine the 
concentration after spiking (A) of each parameter. Calculate each 
percent recovery (P) as 100 (A-B)%/T, where T is the known true value of 
the spike.
    8.3.3  Compare the percent recovery (P) for each parameter with the 
corresponding QC acceptance criteria found in Table 2. These acceptance 
criteria were calculated to include an allowance for error in 
measurement of both the background and spike concentrations, assuming a 
spike to background ratio of 5:1. This error will be accounted for to 
the extent that the analyst's spike to background ratio approaches 
5:1.\7\ If spiking was performed at a concentration lower than the test 
concentration in Section 8.2.2, the analyst must use either the QC 
acceptance criteria in Table 2, or optional QC acceptance criteria 
calculated for the specific spike concentration. To calculate optional 
acceptance criteria for the recovery of a parameter: (1) Calculate 
accuracy (X') using the equation in Table 3, substituting the spike 
concentration (T) for C; (2) calculate overall precision (S') using the 
equation in Table 3, substituting X' for X8; (3) calculate the range for 
recovery at the spike concentration as (100 X'/T)  2.44 (100 
S'/T)%.\7\
    8.3.4  If any individual P falls outside the designated range for 
recovery, that parameter has failed the acceptance criteria. A check 
standard containing each parameter that failed the criteria must be 
analyzed as described in Section 8.4.
    8.4.  If any parameter fails the acceptance criteria for recovery in 
Section 8.3, a QC check standard containing each parameter that failed 
must be prepared and analyzed.

    Note: The frequency for the required analysis of a QC check standard 
will depend upon the number of parameters being simultaneously tested, 
the complexity of the sample matrix, and the performance of the 
laboratory.

    8.4.1  Prepare the QC check standard by adding 1.0 mL of QC check 
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The 
QC check standard needs only to contain the parameters that failed 
criteria in the test in Section 8.3.
    8.4.2  Analyze the QC check standard to determine the concentration 
measured (A) of each parameter. Calculate each percent recovery 
(Ps) as 100 (A/T)%, where T is the true value of the standard 
concentration.
    8.4.3  Compare the percent recovery (Ps) for each parameter 
with the corresponding QC acceptance criteria found in Table 2. Only 
parameters that failed the test in Section 8.3 need to be compared with 
these criteria. If the recovery of any such parameter falls outside the 
designated range, the laboratory performance for that parameter is 
judged to be out of control, and the problem must be immediately 
identified and corrected. The analytical result for that parameter in 
the unspiked sample is suspect and may not be reported for regulatory 
compliance purposes.
    8.5  As part of QC program for the laboratory, method accuracy for 
wastewater samples must be assessed and records must be maintained. 
After the analysis of five spiked wastewater samples as in Section 8.3, 
calculate the average percent recovery (P) and the standard deviation of 
the percent recovery (sp). Express the accuracy assessment as a 
percent recovery interval from P-2sp to P+2sp. If P=90% and 
sp = 10%, for example, the accuracy interval is expressed as 70-
110%. Update the accuracy assessment for each parameter on a regular 
basis (e.g. after each five to ten new accuracy measurements).
    8.6  It is recommended that the laboratory adopt additional quality 
assurance practices for use with this method. The specific practices 
that are most productive depend upon the needs of the laboratory and the 
nature of the samples. Field duplicates may be analyzed to assess the 
precision of the environmental measurements. When doubt exists over the 
identification of a peak on the chromatogram, confirmatory techniques 
such as gas chromatography with a dissimilar column, specific element 
detector, or mass spectrometer must be used. Whenever possible, the 
laboratory should analyze standard reference materials and participate 
in relevant performance evaluation studies.

            9. Sample Collection, Preservation, and Handling

    9.1  Grab samples must be collected in glass containers. 
Conventional sampling practices \8\ should be followed, except that the 
bottle must not be prerinsed with sample before collection. Composite 
samples should be collected in refrigerated glass containers in 
accordance with the requirements of the program. Automatic sampling 
equipment must be as free as possible of Tygon tubing and other 
potential sources of contamination.
    9.2  All samples must be iced or refrigerated at 4  deg.C from the 
time of collection until extraction.
    9.3  All samples must be extracted within 7 days of collection and 
completely analyzed within 40 days of extraction.\2\

[[Page 138]]

                          10. Sample Extraction

    10.1  Mark the water meniscus on the side of the sample bottle for 
later determination of sample volume. Pour the entire sample into a 2-L 
separatory funnel. Check the pH of the sample with wide-range pH paper 
and adjust to within the range of 5 to 9 with sodium hydroxide solution 
or sulfuric acid.
    10.2  Add 60 mL of methylene chloride to the sample bottle, seal, 
and shake 30 s to rinse the inner surface. Transfer the solvent to the 
separatory funnel and extract the sample by shaking the funnel for 2 
min. with periodic venting to release excess pressure. Allow the organic 
layer to separate from the water phase for a minimum of 10 min. If the 
emulsion interface between layers is more than one-third the volume of 
the solvent layer, the analyst must employ mechanical techniques to 
complete the phase separation. The optimum technique depends upon the 
sample, but may include stirring, filtration of the emulsion through 
glass wool, centrifugation, or other physical methods. Collect the 
methylene chloride extract in a 250-mL Erlenmeyer flask.
    10.3  Add a second 60-mL volume of methylene chloride to the sample 
bottle and repeat the extraction procedure a second time, combining the 
extracts in the Erlenmeyer flask. Perform a third extraction in the same 
manner.
    10.4  Assemble a Kuderna-Danish (K-D) concentrator by attaching a 
10-mL concentrator tube to a 500-mL evaporative flask. Other 
concentration devices or techniques may be used in place of the K-D 
concentrator if the requirements of Section 8.2 are met.
    10.5  Pour the combined extract through a solvent-rinsed drying 
column containing about 10 cm of anhydrous sodium sulfate, and collect 
the extract in the K-D concentrator. Rinse the Erlenmeyer flask and 
column with 20 to 30 mL of methylene chloride to complete the 
quantitative transfer.
    10.6  Sections 10.7 and 10.8 describe a procedure for exchanging the 
methylene chloride solvent to hexane while concentrating the extract 
volume to 1.0 mL. When it is not necessary to achieve the MDL in Table 
2, the solvent exchange may be made by the addition of 50 mL of hexane 
and concentration to 10 mL as described in Method 606, Sections 10.7 and 
10.8.
    10.7  Add one or two clean boiling chips to the evaporative flask 
and attach a three-ball Snyder column. Prewet the Snyder column by 
adding about 1 mL of methylene chloride to the top. Place the K-D 
apparatus on a hot water bath (60 to 65  deg.C) so that the concentrator 
tube is partially immersed in the hot water, and the entire lower 
rounded surface of the flask is bathed with hot vapor. Adjust the 
vertical position of the apparatus and the water temperature as required 
to complete the concentration in 15 to 20 min. At the proper rate of 
distillation the balls of the column will actively chatter but the 
chambers will not flood with condensed solvent. When the apparent volume 
of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain 
and cool for at least 10 min.
    10.8  Remove the Snyder column and rinse the flask and its lower 
joint into the concentrator tube with 1 to 2 mL of methylene chloride. A 
5-mL syringe is recommended for this operation. Add 1 to 2 mL of hexane 
and a clean boiling chip to the concentrator tube and attach a two-ball 
micro-Snyder column. Prewet the column by adding about 0.5 mL of hexane 
to the top. Place the micro-K-D apparatus on a hot water bath (60 to 65  
deg.C) so that the concentrator tube is partially immersed in the hot 
water. Adjust the vertical position of the apparatus and the water 
temperature as required to complete the concentration in 5 to 10 min. At 
the proper rate of distillation the balls of the column will actively 
chatter but the chambers will not flood. When the apparent volume of 
liquid reaches 0.5 mL, remove the K-D apparatus and allow it to drain 
and cool for at least 10 min.
    10.9  Remove the micro-Snyder column and rinse its lower joint into 
the concentrator tube with a minimum amount of hexane. Adjust the 
extract volume to 1.0 mL. Stopper the concentrator tube and store 
refrigerated if further processing will not be performed immediately. If 
the extract will be stored longer than two days, it should be 
transferred to a Teflon-sealed screw-cap vial. If the sample extract 
requires no further cleanup, proceed with gas chromatographic analysis 
(Section 12). If the sample requires further cleanup, proceed to Section 
11.
    10.10  Determine the original sample volume by refilling the sample 
bottle to the mark and transferring the liquid to a 1000-mL graduated 
cylinder. Record the sample volume to the nearest 5 mL.

                       11. Cleanup and Separation

    11.1  Cleanup procedures may not be necessary for a relatively clean 
sample matrix. If particular circumstances demand the use of a cleanup 
procedure, the analyst may use the procedure below or any other 
appropriate procedure. However, the analyst first must demonstrate that 
the requirements of Section 8.2 can be met using the method as revised 
to incorporate the cleanup procedure.
    11.2  Florisil column cleanup:
    11.2.1  Prepare a slurry of 10 g of activated Florisil in methylene 
chloride/hexane (1+9)(V/V) and place the Florisil into a chromatographic 
column. Tap the column to settle the Florisil and add 1 cm of anhydrous 
sodium sulfate to the top. Adjust the elution rate to about 2 mL/min.

[[Page 139]]

    11.2.2  Just prior to exposure of the sodium sulfate layer to the 
air, quantitatively transfer the sample extract onto the column using an 
additional 2 mL of hexane to complete the transfer. Just prior to 
exposure of the sodium sulfate layer to the air, add 30 mL of methylene 
chloride/hexane (1 + 9)(V/V) and continue the elution of the column. 
Discard the eluate.
    11.2.3  Next, elute the column with 30 mL of acetone/methylene 
chloride (1 + 9)(V/V) into a 500-mL K-D flask equipped with a 10-mL 
concentrator tube. Concentrate the collected fraction as in Sections 
10.6, 10.7, 10.8, and 10.9 including the solvent exchange to 1 mL of 
hexane. This fraction should contain the nitroaromatics and isophorone. 
Analyze by gas chromatography (Section 12).

                         12. Gas Chromatography

    12.1  Isophorone and nitrobenzene are analyzed by injection of a 
portion of the extract into an FIDGC. The dinitrotoluenes are analyzed 
by a separate injection into an ECDGC. Table 1 summarizes the 
recommended operating conditions for the gas chromatograph. Included in 
this table are retention times and MDL that can be achieved under these 
conditions. Examples of the separations achieved by Column 1 are shown 
in Figures 1 and 2. Other packed or capillary (open-tubular) columns, 
chromatographic conditions, or detectors may be used if the requirements 
of Section 8.2 are met.
    12.2  Calibrate the system daily as described in Section 7.
    12.3  If the internal standard calibration procedure is being used, 
the internal standard must be added to the same extract and mixed 
thoroughly immediately before injection into the gas chromatograph.
    12.4  Inject 2 to 5 L of the sample extract or standard 
into the gas chromatograph using the solvent-flush technique.\9\ Smaller 
(1.0 L) volumes may be injected if automatic devices are 
employed. Record the volume injected to the nearest 0.05 L, the 
total extract volume, and the resulting peak size in area or peak height 
units.
    12.5  Identify the parameters in the sample by comparing the 
retention times of the peaks in the sample chromatogram with those of 
the peaks in standard chromatograms. The width of the retention time 
window used to make identifications should be based upon measurements of 
actual retention time variations of standards over the course of a day. 
Three times the standard deviation of a retention time for a compound 
can be used to calculate a suggested window size; however, the 
experience of the analyst should weigh heavily in the interpretation of 
chromatograms.
    12.6  If the response for a peak exceeds the working range of the 
system, dilute the extract and reanalyze.
    12.7  If the measurement of the peak response is prevented by the 
presence of interferences, further cleanup is required.

                            13. Calculations

    13.1  Determine the concentration of individual compounds in the 
sample.
    13.1.1  If the external standard calibration procedure is used, 
calculate the amount of material injected from the peak response using 
the calibration curve or calibration factor determined in Section 7.2.2. 
The concentration in the sample can be calculated from Equation 2.

                                                                                                                
                                                                           (A)(Vt)                              
                                        Concentration (g/  = -----------------                         
                                                    L)                     (Vi)(Vs)                             
                                                                                                                

                                                              Equation 2
where:
    A=Amount of material injected (ng).
    Vi=Volume of extract injected (L).
    Vt=Volume of total extract (L).
    Vs=Volume of water extracted (mL).

    13.1.2  If the internal standard calibration procedure is used, 
calculate the concentration in the sample using the response factor (RF) 
determined in Section 7.3.2 and Equation 3.

                                                                                                                
                                                                           (As)(Is)                             
                                        Concentration (g/  = -----------------                         
                                                    L)                  (Ais)(RF)(Vo)                           
                                                                                                                

                                                              Equation 3
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Is=Amount of internal standard added to each extract 
(g).
    Vo=Volume of water extracted (L).

    13.2  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

                         14. Method Performance

    14.1  The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the value is above zero.\1\ The MDL concentrations 
listed in Table 1 were obtained using reagent water.\10\ Similar results 
were achieved using representative wastewaters. The MDL actually 
achieved in a given analysis will vary depending on instrument 
sensitivity and matrix effects.
    14.2  This method has been tested for linearity of spike recovery 
from reagent water and has been demonstrated to be applicable over the 
concentration range from 7 x MDL to 1000 x MDL.\10\

[[Page 140]]

    14.3  This method was tested by 18 laboratories using reagent water, 
drinking water, surface water, and three industrial wastewaters spiked 
at six concentrations over the range 1.0 to 515 g/L.\11\ Single 
operator precision, overall precision, and method accuracy were found to 
be directly related to the concentration of the parameter and 
essentially independent of the sample matrix. Linear equations to 
describe these relationships are presented in Table 3.

                               References

    1. 40 CFR part 136, appendix B.
    2. ``Determination of Nitroaromatic Compounds and Isophorone in 
Industrial and Municipal Wastewaters,'' EPA 600/ 4-82-024, National 
Technical Information Service, PB82-208398, Springfield, Virginia 22161, 
May 1982.
    3. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard 
Practices for Preparation of Sample Containers and for Preservation of 
Organic Constituents,'' American Society for Testing and Materials, 
Philadelphia.
    4. ``Carcinogens--Working With Carcinogens,'' Department of Health, 
Education, and Welfare, Public Health Service, Center for Disease 
Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    5. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR 
part 1910), Occupational Safety and Health Administration, OSHA 2206 
(Revised, January 1976).
    6. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent 
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44 
used in the equation in Section 8.3.3 is two times the value 1.22 
derived in this report.)
    8. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard 
Practices for Sampling Water,'' American Society for Testing and 
Materials, Philadelphia.
    9. Burke, J.A. ``Gas Chromatography for Pesticide Residue Analysis; 
Some Practical Aspects,'' Journal of the Association of Official 
Analytical Chemists, 48, 1037 (1965).
    10. ``Determination of Method Detection Limit and Analytical Curve 
for EPA Method 609--Nitroaromatics and Isophorone,'' Special letter 
report for EPA Contract 68-03-2624, U.S. Environmental Protection 
Agency, Environmental Monitoring and Support Laboratory, Cincinnati, 
Ohio 45268, June 1980.
    11. ``EPA Method Study 19, Method 609 (Nitroaromatics and 
Isophorone),'' EPA 600/4-84-018, National Technical Information Service, 
PB84-176908, Springfield, Virginia 22161, March 1984.

                         Table 1--Chromatographic Conditions and Method Detection Limits                        
----------------------------------------------------------------------------------------------------------------
                                                             Retention time (min)       Method detection limit  
                                                         ----------------------------       (g/L)      
                        Parameter                                                    ---------------------------
                                                             Col. 1        Col. 2         ECDGC         FIDGC   
----------------------------------------------------------------------------------------------------------------
Nitrobenzene............................................        3.31          4.31         13.7           3.6   
2,6-Dinitrotoluene......................................        3.52          4.75          0.01          -     
Isophorone..............................................        4.49          5.72         15.7           5.7   
2,4-Dinitrotoluene......................................        5.35          6.54          0.02          -     
----------------------------------------------------------------------------------------------------------------
 AAColumn 1 conditions: Gas-Chrom Q (80/100 mesh) coated with 1.95% QF-1/1.5% OV-17 packed in a 1.2 m long  x  2
  mm or 4 mm ID glass column. A 2 mm ID column and nitrogen carrier gas at 44 mL/min flow rate were used when   
  determining isophorone and nitrobenzene by FIDGC. The column temperature was held isothermal at 85 C. A 4 mm  
  ID column and 10% methane/90% argon carrier gas at 44 mL/min flow rate were used when determining the         
  dinitrotoluenes by ECDGC. The column temperature was held isothermal at 145 C.                                
 AAColumn 2 conditions: Gas-Chrom Q (80/100 mesh) coated with 3% OV-101 packed in a 3.0 m long  x  2 mm or 4 mm 
  ID glass column. A 2 mm ID column and nitrogen carrier gas at 44 mL/min flow rate were used when determining  
  isophorone and nitrobenzene by FIDGC. The column temperature was held isothermal at 100 C. A 4 mm ID column   
  and 10% methane/90% argon carrier gas at 44 mL/min flow rate were used when determining the dinitrotoluenes by
  ECDGC. The column temperature was held isothermal at 150 C.                                                   


                                   Table 2--QC Acceptance Criteria--Method 609                                  
----------------------------------------------------------------------------------------------------------------
                                                                                        Range for X             
                                                            Test Conc.    Limit for s  (g/   Range for 
                        Parameter                          (g/  (g/       L)        P, Ps!(%) 
                                                                L)            L)                                
----------------------------------------------------------------------------------------------------------------
2,4-Dinitrotoluene.......................................            20           5.1  3.6-22.8            6-125
2,6-Dinitrotoluene.......................................            20           4.8  3.8-23.0            8-126
Isophorone...............................................           100          32.3  8.0-100.0           D-117
Nitrobenzene.............................................           100          33.3  25.7-100.0          6-118
----------------------------------------------------------------------------------------------------------------
s=Standard deviation of four recovery measurements, in g/L (Section 8.2.4).                            
X=Average recovery for four recovery measurements, in g/L (Section 8.2.4).                             
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).                                                 
D=Detected; result must be greater than zero.                                                                   
                                                                                                                
Note: These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits
  for recovery have been broadened to assure applicability of the limits to concentrations below those used to  
  develop Table 3.                                                                                              


[[Page 141]]


                Table 3--Method Accuracy and Precision as Functions of Concentration--Method 609                
----------------------------------------------------------------------------------------------------------------
                                                            Accuracy, as      Single analyst        Overall     
                       Parameter                            recovery, X       precision, sr       precision, S  
                                                           (g/L)     (g/L)     (g/L) 
----------------------------------------------------------------------------------------------------------------
2,4-Dinitro-                                                                                                    
  toluene..............................................         0.65C+0.22         0.20X+0.08         0.37X-0.07
2,6-Dinitro-                                                                                                    
  toluene..............................................         0.66C+0.20         0.19X+0.06         0.36X-0.00
Isophorone.............................................         0.49C+2.93         0.28X+2.77         0.46X+0.31
Nitrobenzene...........................................         0.60C+2.00         0.25X+2.53         0.37X-0.78
----------------------------------------------------------------------------------------------------------------
X=Expected recovery for one or more measurements of a sample containing a concentration of C, in g/L.  
sr=Expected single analyst standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
S=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
C=True value for the concentration, in g/L.                                                            
X=Average recovery found for measurements of samples containing a concentration of C, in g/L.          


[[Page 142]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.029


[[Page 143]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.030


[[Page 144]]

              Method 610--Polynuclear Aromatic Hydrocarbons

                        1. Scope and Application

    1.1  This method covers the determination of certain polynuclear 
aromatic hydrocarbons (PAH). The following parameters can be determined 
by this method:

------------------------------------------------------------------------
                  Parameter                    STORET No.      CAS No.  
------------------------------------------------------------------------
Acenaphthene................................         34205       83-32-9
Acenaphthylene..............................         34200      208-96-8
Anthracene..................................         34220      120-12-7
Benzo(a)anthracene..........................         34526       56-55-3
Benzo(a)pyrene..............................         34247       50-32-8
Benzo(b)fluoranthene........................         34230      205-99-2
Benzo(ghi)perylene..........................         34521      191-24-2
Benzo(k)fluoranthene........................         34242      207-08-9
Chrysene....................................         34320      218-01-9
Dibenzo(a,h)anthracene......................         34556       53-70-3
Fluoranthene................................         34376      206-44-0
Fluorene....................................         34381       86-73-7
Indeno(1,2,3-cd)pyrene......................         34403      193-39-5
Naphthalene.................................         34696       91-20-3
Phenanthrene................................         34461       85-01-8
Pyrene......................................         34469      129-00-0
------------------------------------------------------------------------

    1.2  This is a chromatographic method applicable to the 
determination of the compounds listed above in municipal and industrial 
discharges as provided under 40 CFR 136.1. When this method is used to 
analyze unfamiliar samples for any or all of the compounds above, 
compound identifications should be supported by at least one additional 
qualitative technique. Method 625 provides gas chromatograph/mass 
spectrometer (GC/MS) conditions appropriate for the qualitative and 
quantitative confirmation of results for many of the parameters listed 
above, using the extract produced by this method.
    1.3  This method provides for both high performance liquid 
chromatographic (HPLC) and gas chromatographic (GC) approaches for the 
determination of PAHs. The gas chromatographic procedure does not 
adequately resolve the following four pairs of compounds: Anthracene and 
phenanthrene; chrysene and benzo(a)anthracene; benzo(b)fluoranthene and 
benzo(k)fluoranthene; and dibenzo(a,h) anthracene and indeno (1,2,3-
cd)pyrene. Unless the purpose for the analysis can be served by 
reporting the sum of an unresolved pair, the liquid chromatographic 
approach must be used for these compounds. The liquid chromatographic 
method does resolve all 16 of the PAHs listed.
    1.4  The method detection limit (MDL, defined in Section 15.1) \1\ 
for each parameter is listed in Table 1. The MDL for a specific 
wastewater may differ from those listed, depending upon the nature of 
interferences in the sample matrix.
    1.5  The sample extraction and concentration steps in this method 
are essentially the same as in Methods 606, 608, 609, 611, and 612. 
Thus, a single sample may be extracted to measure the parameters 
included in the scope of each of these methods. When cleanup is 
required, the concentration levels must be high enough to permit 
selecting aliquots, as necessary, to apply appropriate cleanup 
procedures. Selection of the aliquots must be made prior to the solvent 
exchange steps of this method. The analyst is allowed the latitude, 
under Sections 12 and 13, to select chromatographic conditions 
appropriate for the simultaneous measurement of combinations of these 
parameters.
    1.6  Any modification of this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5.
    1.7  This method is restricted to use by or under the supervision of 
analysts experienced in the use of HPLC and GC systems and in the 
interpretation of liquid and gas chromatograms. Each analyst must 
demonstrate the ability to generate acceptable results with this method 
using the procedure described in Section 8.2.

                          2. Summary of Method

    2.1  A measured volume of sample, approximately 1-L, is extracted 
with methylene chloride using a separatory funnel. The methylene 
chloride extract is dried and concentrated to a volume of 10 mL or less. 
The extract is then separated by HPLC or GC. Ultraviolet (UV) and 
fluorescence detectors are used with HPLC to identify and measure the 
PAHs. A flame ionization detector is used with GC.\2\
    2.2  The method provides a silica gel column cleanup procedure to 
aid in the elimination of interferences that may be encountered.

                            3. Interferences

    3.1  Method interferences may be caused by contaminants in solvents, 
reagents, glassware, and other sample processing hardward that lead to 
discrete artifacts and/or elevated baselines in the chromatograms. All 
of these materials must be routinely demonstrated to be free from 
interferences under the conditions of the analysis by running laboratory 
reagent blanks as described in Section 8.1.3.
    3.1.1  Glassware must be scrupulously cleaned.\3\ Clean all 
glassware as soon as possible after use by rinsing with the last solvent 
used in it. Solvent rinsing should be followed by detergent washing with 
hot water, and rinses with tap water and distilled water. The glassware 
should then be drained dry, and heated in a muffle furnace at 400  deg.C 
for 15 to 30 min. Some thermally stable materials, such as PCBs, may not 
be eliminated by this treatment. Solvent rinses with acetone and 
pesticide quality hexane may be

[[Page 145]]

substituted for the muffle furnace heating. Thorough rinsing with such 
solvents usually eliminates PCB interference. Volumetric ware should not 
be heated in a muffle furnace. After drying and cooling, glassware 
should be sealed and stored in a clean environment to prevent any 
accumulation of dust or other contaminants. Store inverted or capped 
with aluminum foil.
    3.1.2  The use of high purity reagents and solvents helps to 
minimize interference problems. Purification of solvents by distillation 
in all-glass systems may be required.
    3.2  Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary 
considerably from source to source, depending upon the nature and 
diversity of the industrial complex or municipality being sampled. The 
cleanup procedure in Section 11 can be used to overcome many of these 
interferences, but unique samples may require additional cleanup 
approaches to achieve the MDL listed in Table 1.
    3.3  The extent of interferences that may be encountered using 
liquid chromatographic techniques has not been fully assessed. Although 
the HPLC conditions described allow for a unique resolution of the 
specific PAH compounds covered by this method, other PAH compounds may 
interfere.

                                4. Safety

    4.1  The toxicity or carcinogenicity of each reagent used in this 
method have not been precisely defined; however, each chemical compound 
should be treated as a potential health hazard. From this viewpoint, 
exposure to these chemicals must be reduced to the lowest possible level 
by whatever means available. The laboratory is responsible for 
maintaining a current awareness file of OSHA regulations regarding the 
safe handling of the chemicals specified in this method. A reference 
file of material data handling sheets should also be made available to 
all personnel involved in the chemical analysis. Additional references 
to laboratory safety are available and have been identified \4\-\6\ 
for the information of the analyst.
    4.2  The following parameters covered by this method have been 
tentatively classified as known or suspected, human or mammalian 
carcinogens: benzo(a)anthracene, benzo(a)pyrene, and dibenzo(a,h)-
anthracene. Primary standards of these toxic compounds should be 
prepared in a hood. A NIOSH/MESA approved toxic gas respirator should be 
worn when the analyst handles high concentrations of these toxic 
compounds.

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete or composite sampling.
    5.1.1  Grab sample bottle--1-L or 1-qt, amber glass, fitted with a 
screw cap lined with Teflon. Foil may be substituted for Teflon if the 
sample is not corrosive. If amber bottles are not available, protect 
samples from light. The bottle and cap liner must be washed, rinsed with 
acetone or methylene chloride, and dried before use to minimize 
contamination.
    5.1.2  Automatic sampler (optional)--The sampler must incorporate 
glass sample containers for the collection of a minimum of 250 mL of 
sample. Sample containers must be kept refrigerated at 4  deg.C and 
protected from light during compositing. If the sampler uses a 
peristaltic pump, a minimum length of compressible silicone rubber 
tubing may be used. Before use, however, the compressible tubing should 
be thoroughly rinsed with methanol, followed by repeated rinsings with 
distilled water to minimize the potential for contamination of the 
sample. An integrating flow meter is required to collect flow 
proportional composites.
    5.2  Glassware (All specifications are suggested. Catalog numbers 
are included for illustration only.):
    5.2.1  Separatory funnel--2-L, with Teflon stopcock.
    5.2.2  Drying column--Chromatographic column, approximately 400 mm 
long  x  19 mm ID, with coarse frit filter disc.
    5.2.3  Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes 
K-570050-1025 or equivalent). Calibration must be checked at the volumes 
employed in the test. Ground glass stopper is used to prevent 
evaporation of extracts.
    5.2.4  Evaporative flask, Kuderna-Danish--500-mL (Kontes K-570001-
0500 or equivalent). Attach to concentrator tube with springs.
    5.2.5  Snyder column, Kuderna-Danish--Three-ball macro (Kontes K-
503000-0121 or equivalent).
    5.2.6  Snyder column, Kuderna-Danish--Two-ball micro (Kontes K-
569001-0219 or equivalent).
    5.2.7  Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
    5.2.8  Chromatographic column--250 mm long x 10 mm ID, with coarse 
frit filter disc at bottom and Teflon stopcock.
    5.3  Boiling chips--Approximately 10/40 mesh. Heat to 400  deg.C for 
30 min or Soxhlet extract with methylene chloride.
    5.4  Water bath--Heated, with concentric ring cover, capable of 
temperature control (2  deg.C). The bath should be used in a 
hood.
    5.5  Balance--Analytical, capable of accurately weighing 0.0001 g.
    5.6  High performance liquid chromatograph (HPLC)--An analytical 
system complete with column supplies, high pressure syringes, detectors, 
and compatible strip-chart recorder. A data system is recommended for 
measuring peak areas and retention times.
    5.6.1  Gradient pumping system--Constant flow.

[[Page 146]]

    5.6.2  Reverse phase column--HC-ODS Sil-X, 5 micron particle 
diameter, in a 25 cm x 2.6 mm ID stainless steel column (Perkin Elmer 
No. 089-0716 or equivalent). This column was used to develop the method 
performance statements in Section 15. Guidelines for the use of 
alternate column packings are provided in Section 12.2.
    5.6.3  Detectors--Fluorescence and/or UV detectors. The fluorescence 
detector is used for excitation at 280 nm and emission greater than 389 
nm cutoff (Corning 3-75 or equivalent). Fluorometers should have 
dispersive optics for excitation and can utilize either filter or 
dispersive optics at the emission detector. The UV detector is used at 
254 nm and should be coupled to the fluorescence detector. These 
detectors were used to develop the method performance statements in 
Section 15. Guidelines for the use of alternate detectors are provided 
in Section 12.2.
    5.7  Gas chromatograph--An analytical system complete with 
temperature programmable gas chromatograph suitable for on-column or 
splitless injection and all required accessories including syringes, 
analytical columns, gases, detector, and strip-chart recorder. A data 
system is recommended for measuring peak areas.
    5.7.1  Column--1.8 m long x 2 mm ID glass, packed with 3% OV-17 on 
Chromosorb W-AW-DCMS (100/120 mesh) or equivalent. This column was used 
to develop the retention time data in Table 2. Guidelines for the use of 
alternate column packings are provided in Section 13.3.
    5.7.2  Detector--Flame ionization detector. This detector has proven 
effective in the analysis of wastewaters for the parameters listed in 
the scope (Section 1.1), excluding the four pairs of unresolved 
compounds listed in Section 1.3. Guidelines for the use of alternate 
detectors are provided in Section 13.3.

                               6. Reagents

    6.1  Reagent water--Reagent water is defined as a water in which an 
interferent is not observed at the MDL of the parameters of interest.
    6.2  Sodium thiosulfate--(ACS) Granular.
    6.3  Cyclohexane, methanol, acetone, methylene chloride, pentane--
Pesticide quality or equivalent.
    6.4  Acetonitrile--HPLC quality, distilled in glass.
    6.5  Sodium sulfate--(ACS) Granular, anhydrous. Purify by heating at 
400  deg.C for 4 h in a shallow tray.
    6.6  Silica gel--100/200 mesh, desiccant, Davison, grade-923 or 
equivalent. Before use, activate for at least 16 h at 130  deg.C in a 
shallow glass tray, loosely covered with foil.
    6.7  Stock standard solutions (1.00 g/L)--Stock 
standard solutions can be prepared from pure standard materials or 
purchased as certified solutions.
    6.7.1  Prepare stock standard solutions by accurately weighing about 
0.0100 g of pure material. Dissolve the material in acetonitrile and 
dilute to volume in a 10-mL volumetric flask. Larger volumes can be used 
at the convenience of the analyst. When compound purity is assayed to be 
96% or greater, the weight can be used without correction to calculate 
the concentration of the stock standard. Commercially prepared stock 
standards can be used at any concentration if they are certified by the 
manufacturer or by an independent source.
    6.7.2  Transfer the stock standard solutions into Teflon-sealed 
screw-cap bottles. Store at 4  deg.C and protect from light. Stock 
standard solutions should be checked frequently for signs of degradation 
or evaporation, especially just prior to preparing calibration standards 
from them.
    6.7.3  Stock standard solutions must be replaced after six months, 
or sooner if comparison with check standards indicates a problem.
    6.8  Quality control check sample concentrate--See Section 8.2.1.

                             7. Calibration

    7.1  Establish liquid or gas chromatographic operating conditions 
equivalent to those given in Table 1 or 2. The chromatographic system 
can be calibrated using the external standard technique (Section 7.2) or 
the internal standard technique (Section 7.3).
    7.2  External standard calibration procedure:
    7.2.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask and diluting to volume 
with acetonitrile. One of the external standards should be at a 
concentration near, but above, the MDL (Table 1) and the other 
concentrations should correspond to the expected range of concentrations 
found in real samples or should define the working range of the 
detector.
    7.2.2  Using injections of 5 to 25 L for HPLC and 2 to 5 
L for GC, analyze each calibration standard according to 
Section 12 or 13, as appropriate. Tabulate peak height or area responses 
against the mass injected. The results can be used to prepare a 
calibration curve for each compound. Alternatively, if the ratio of 
response to amount injected (calibration factor) is a constant over the 
working range (<10% relative standard deviation, RSD), linearity through 
the origin can be assumed and the average ratio or calibration factor 
can be used in place of a calibration curve.
    7.3  Internal standard calibration procedure--To use this approach, 
the analyst must select one or more internal standards that are similar 
in analytical behavior to the

[[Page 147]]

compounds of interest. The analyst must further demonstrate that the 
measurement of the internal standard is not affected by method or matrix 
interferences. Because of these limitations, no internal standard can be 
suggested that is applicable to all samples.
    7.3.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask. To each calibration 
standard, add a known constant amount of one or more internal standards, 
and dilute to volume with acetonitrile. One of the standards should be 
at a concentration near, but above, the MDL and the other concentrations 
should correspond to the expected range of concentrations found in real 
samples or should define the working range of the detector.
    7.3.2  Using injections of 5 to 25 L for HPLC and 2 to 5 
L for GC, analyze each calibration standard according to 
Section 12 or 13, as appropriate. Tabulate peak height or area responses 
against concentration for each compound and internal standard. Calculate 
response factors (RF) for each compound using Equation 1.

                                                                        
                                          (As)(Cis)                     
                                    RF=  -----------                    
                                          (Ais)(Cs)                     
                                                                        

                                                              Equation 1
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Cis=Concentration of the internal standard (g/L).
    Cs=Concentration of the parameter to be measured (g/
L).

If the RF value over the working range is a constant (<10% RSD), the RF 
can be assumed to be invariant and the average RF can be used for 
calculations. Alternatively, the results can be used to plot a 
calibration curve of response ratios, As/Ais, vs. RF.

    7.4  The working calibration curve, calibration factor, or RF must 
be verified on each working day by the measurement of one or more 
calibration standards. If the response for any parameter varies from the 
predicted response by more than 15%, the test must be 
repeated using a fresh calibration standard. Alternatively, a new 
calibration curve must be prepared for that compound.
    7.5  Before using any cleanup procedure, the analyst must process a 
series of calibration standards through the procedure to validate 
elution patterns and the absence of interferences from the reagents.

                           8. Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality control program. The minimum requirements of this program 
consist of an initial demonstration of laboratory capability and an 
ongoing analysis of spiked samples to evaluate and document data 
quality. The laboratory must maintain records to document the quality of 
data that is generated. Ongoing data quality checks are compared with 
established performance criteria to determine if the results of analyses 
meet the performance characteristics of the method. When results of 
sample spikes indicate atypical method performance, a quality control 
check standard must be analyzed to confirm that the measurements were 
performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occurring in 
chromatography, the analyst is permitted certain options (detailed in 
Sections 10.4, 11.1, 12.2, and 13.3) to improve the separations or lower 
the cost of measurements. Each time such a modification is made to the 
method, the analyst is required to repeat the procedure in Section 8.2.
    8.1.3  Before processing any samples the analyst must analyze a 
reagent water blank to demonstrate that interferences from the 
analytical system and glassware are under control. Each time a set of 
samples is extracted or reagents are changed a reagent water blank must 
be processed as a safeguard against laboratory contamination.
    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 10% of all samples to monitor and evaluate laboratory data 
quality. This procedure is described in Section 8.3.
    8.1.5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 10% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.5.
    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality control (QC) check sample concentrate is required 
containing each parameter of interest at the following concentrations in 
acetonitrile: 100 g/mL of any

[[Page 148]]

of the six early-eluting PAHs (naphthalene, acenaphthylene, 
acenaphthene, fluorene, phenanthrene, and anthracene); 5 g/mL 
of benzo(k)fluoranthene; and 10 g/mL of any of the other PAHs. 
The QC check sample concentrate must be obtained from the U.S. 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory in Cincinnati, Ohio, if available. If not available from that 
source, the QC check sample concentrate must be obtained from another 
external source. If not available from either source above, the QC check 
sample concentrate must be prepared by the laboratory using stock 
standards prepared independently from those used for calibration.
    8.2.2  Using a pipet, prepare QC check samples at the test 
concentrations shown in Table 3 by adding 1.00 mL of QC check sample 
concentrate to each of four 1-L aliquots of reagent water.
    8.2.3  Analyze the well-mixed QC check samples according to the 
method beginning in Section 10.
    8.2.4  Calculate the average recovery (X) in g/L, and the 
standard deviation of the recovery (s) in g/L, for each 
parameter using the four results.
    8.2.5  For each parameter compare s and X with the corresponding 
acceptance criteria for precision and accuracy, respectively, found in 
Table 3. If s and X for all parameters of interest meet the acceptance 
criteria, the system performance is acceptable and analysis of actual 
samples can begin. If any individual s exceeds the precision limit or 
any individual X falls outside the range for accuracy, the system 
performance is unacceptable for that parameter.

    Note: The large number of parameters in Table 3 present a 
substantial probability that one or more will fail at least one of the 
acceptance criteria when all parameters are analyzed.

    8.2.6  When one or more of the parameters tested fail at least one 
of the acceptance criteria, the analyst must proceed according to 
Section 8.2.6.1 or 8.2.6.2.
    8.2.6.1  Locate and correct the source of the problem and repeat the 
test for all parameters of interest beginning with Section 8.2.2.
    8.2.6.2  Beginning with Section 8.2.2, repeat the test only for 
those parameters that failed to meet criteria. Repeated failure, 
however, will confirm a general problem with the measurement system. If 
this occurs, locate and correct the source of the problem and repeat the 
test for all compounds of interest beginning with Section 8.2.2.
    8.3  The laboratory must, on an ongoing basis, spike at least 10% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing one to ten samples per month, at least one 
spiked sample per month is required.
    8.3.1  The concentration of the spike in the sample should be 
determined as follows:
    8.3.1.1  If, as in compliance monitoring, the concentration of a 
specific parameter in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of a specific parameter in the sample 
is not being checked against a limit specific to that parameter, the 
spike should be at the test concentration in Section 8.2.2 or 1 to 5 
times higher than the background concentration determined in Section 
8.3.2, whichever concentration would be larger.
    8.3.1.3  If it is impractical to determine background levels before 
spiking (e.g., maximum holding times will be exceeded), the spike 
concentration should be (1) the regulatory concentration limit, if any; 
or, if none, (2) the larger of either 5 times higher than the expected 
background concentration or the test concentration in Section 8.2.2.
    8.3.2  Analyze one sample aliquot to determine the background 
concentration (B) of each parameter. If necessary, prepare a new QC 
check sample concentrate (Section 8.2.1) appropriate for the background 
concentrations in the sample. Spike a second sample aliquot with 1.0 mL 
of the QC check sample concentrate and analyze it to determine the 
concentration after spiking (A) of each parameter. Calculate each 
percent recovery (P) as 100 (A-B)%/T, where T is the known true value of 
the spike.
    8.3.3  Compare the percent recovery (P) for each parameter with the 
corresponding QC acceptance criteria found in Table 3. These acceptance 
criteria were calculated to include an allowance for error in 
measurement of both the background and spike concentrations, assuming a 
spike to background ratio of 5:1. This error will be accounted for to 
the extent that the analyst's spike to background ratio approaches 
5:1.\7\ If spiking was performed at a concentration lower than the test 
concentration in Section 8.2.2, the analyst must use either the QC 
acceptance criteria in Table 3, or optional QC acceptance criteria 
calculated for the specific spike concentration. To calculate optional 
acceptance criteria for the recovery of a parameter: (1) Calculate 
accuracy (X') using the equation in Table 4, substituting the spike 
concentration (T) for C; (2) calculate overall precision (S') using the 
equation in Table 4, substituting X' for X; (3) calculate the range for 
recovery at the spike concentration as (100 X'/T)2.44(100 
S'/T)%.\7\
    8.3.4  If any individual P falls outside the designated range for 
recovery, that parameter has failed the acceptance criteria. A check 
standard containing each parameter

[[Page 149]]

that failed the critiera must be analyzed as described in Section 8.4.
    8.4  If any parameter fails the acceptance criteria for recovery in 
Section 8.3, a QC check standard containing each parameter that failed 
must be prepared and analyzed.

    Note: The frequency for the required analysis of a QC check standard 
will depend upon the number of parameters being simultaneously tested, 
the complexity of the sample matrix, and the performance of the 
laboratory. If the entire list of parameters in Table 3 must be measured 
in the sample in Section 8.3, the probability that the analysis of a QC 
check standard will be required is high. In this case the QC check 
standard should be routinely analyzed with the spike sample.

    8.4.1  Prepare the QC check standard by adding 1.0 mL of QC check 
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The 
QC check standard needs only to contain the parameters that failed 
criteria in the test in Section 8.3.
    8.4.2  Analyze the QC check standard to determine the concentration 
measured (A) of each parameter. Calculate each percent recovery 
(Ps) as 100 (A/T)%, where T is the true value of the standard 
concentration.
    8.4.3  Compare the percent recovery (Ps) for each parameter 
with the corresponding QC acceptance criteria found in Table 3. Only 
parameters that failed the test in Section 8.3 need to be compared with 
these criteria. If the recovery of any such parameter falls outside the 
designated range, the laboratory performance for that parameter is 
judged to be out of control, and the problem must be immediately 
identified and corrected. The analytical result for that parameter in 
the unspiked sample is suspect and may not be reported for regulatory 
compliance purposes.
    8.5  As part of the QC program for the laboratory, method accuracy 
for wastewater samples must be assessed and records must be maintained. 
After the analysis of five spiked wastewater samples as in Section 8.3, 
calculate the average percent recovery (P) and the standard deviation of 
the percent recovery (sp). Express the accuracy assessment as a 
percent recovery interval from P-2sp to P+2sp. If P=90% and 
sp=10%, for example, the accuracy interval is expressed as 70-110%. 
Update the accuracy assessment for each parameter on a regular basis 
(e.g. after each five to ten new accuracy measurements).
    8.6  It is recommended that the laboratory adopt additional quality 
assurance practices for use with this method. The specific practices 
that are most productive depend upon the needs of the laboratory and the 
nature of the samples. Field duplicates may be analyzed to assess the 
precision of the environmental measurements. When doubt exists over the 
identification of a peak on the chromatogram, confirmatory techniques 
such as gas chromatography with a dissimilar column, specific element 
detector, or mass spectrometer must be used. Whenever possible, the 
laboratory should analyze standard reference materials and participate 
in relevant performance evaluation studies.

            9. Sample Collection, Preservation, and Handling

    9.1  Grab samples must be collected in glass containers. 
Conventional sampling practices \8\ should be followed, except that the 
bottle must not be prerinsed with sample before collection. Composite 
samples should be collected in refrigerated glass containers in 
accordance with the requirements of the program. Automatic sampling 
equipment must be as free as possible of Tygon tubing and other 
potential sources of contamination.
    9.2  All samples must be iced or refrigerated at 4  deg.C from the 
time of collection until extraction. PAHs are known to be light 
sensitive; therefore, samples, extracts, and standards should be stored 
in amber or foil-wrapped bottles in order to minimize photolytic 
decomposition. Fill the sample bottles and, if residual chlorine is 
present, add 80 mg of sodium thiosulfate per liter of sample and mix 
well. EPA Methods 330.4 and 330.5 may be used for measurement of 
residual chlorine.\9\ Field test kits are available for this purpose.
    9.3  All samples must be extracted within 7 days of collection and 
completely analyzed within 40 days of extraction.\2\

                          10. Sample Extraction

    10.1  Mark the water meniscus on the side of the sample bottle for 
later determination of sample volume. Pour the entire sample into a 2-L 
separatory funnel.
    10.2  Add 60 mL of methylene chloride to the sample bottle, seal, 
and shake 30 s to rinse the inner surface. Transfer the solvent to the 
separatory funnel and extract the sample by shaking the funnel for 2 
min. with periodic venting to release excess pressure. Allow the organic 
layer to separate from the water phase for a minimum of 10 min. If the 
emulsion interface between layers is more than one-third the volume of 
the solvent layer, the analyst must employ mechanical techniques to 
complete the phase separation. The optimum technique depends upon the 
sample, but may include stirring, filtration of the emulsion through 
glass wool, centrifugation, or other physical methods. Collect the 
methylene chloride extract in a 250-mL Erlenmeyer flask.
    10.3  Add a second 60-mL volume of methylene chloride to the sample 
bottle and repeat the extraction procedure a second time, combining the 
extracts in the Erlenmeyer flask. Perform a third extraction in the same 
manner.

[[Page 150]]

    10.4  Assemble a Kuderna-Danish (K-D) concentrator by attaching a 
10-mL concentrator tube to a 500-mL evaporative flask. Other 
concentration devices or techniques may be used in place of the K-D 
concentrator if the requirements of Section 8.2 are met.
    10.5  Pour the combined extract through a solvent-rinsed drying 
column containing about 10 cm of anhydrous sodium sulfate, and collect 
the extract in the K-D concentrator. Rinse the Erlenmeyer flask and 
column with 20 to 30 mL of methylene chloride to complete the 
quantitative transfer.
    10.6  Add one or two clean boiling chips to the evaporative flask 
and attach a three-ball Snyder column. Prewet the Snyder column by 
adding about 1 mL of methylene chloride to the top. Place the K-D 
apparatus on a hot water bath (60 to 65  deg.C) so that the concentrator 
tube is partially immersed in the hot water, and the entire lower 
rounded surface of the flask is bathed with hot vapor. Adjust the 
vertical position of the apparatus and the water temperature as required 
to complete the concentration in 15 to 20 min. At the proper rate of 
distillation the balls of the column will actively chatter but the 
chambers will not flood with condensed solvent. When the apparent volume 
of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain 
and cool for at least 10 min.
    10.7  Remove the Snyder column and rinse the flask and its lower 
joint into the concentrator tube with 1 to 2 mL of methylene chloride. A 
5-mL syringe is recommended for this operation. Stopper the concentrator 
tube and store refrigerated if further processing will not be performed 
immediately. If the extract will be stored longer than two days, it 
should be transferred to a Teflon-sealed screw-cap vial and protected 
from light. If the sample extract requires no further cleanup, proceed 
with gas or liquid chromatographic analysis (Section 12 or 13). If the 
sample requires further cleanup, proceed to Section 11.
    10.8  Determine the original sample volume by refilling the sample 
bottle to the mark and transferring the liquid to a 1000-mL graduated 
cylinder. Record the sample volume to the nearest 5 mL.

                       11. Cleanup and Separation

    11.1  Cleanup procedures may not be necessary for a relatively clean 
sample matrix. If particular circumstances demand the use of a cleanup 
procedure, the analyst may use the procedure below or any other 
appropriate procedure. However, the analyst first must demonstrate that 
the requirements of Section 8.2 can be met using the methods as revised 
to incorporate the cleanup procedure.
    11.2  Before the silica gel cleanup technique can be utilized, the 
extract solvent must be exchanged to cyclohexane. Add 1 to 10 mL of the 
sample extract (in methylene chloride) and a boiling chip to a clean K-D 
concentrator tube. Add 4 mL of cyclohexane and attach a two-ball micro-
Snyder column. Prewet the column by adding 0.5 mL of methylene chloride 
to the top. Place the micro-K-D apparatus on a boiling (100  deg.C) 
water bath so that the concentrator tube is partially immersed in the 
hot water. Adjust the vertical position of the apparatus and the water 
temperature as required to complete concentration in 5 to 10 min. At the 
proper rate of distillation the balls of the column will actively 
chatter but the chambers will not flood. When the apparent volume of the 
liquid reaches 0.5 mL, remove the K-D apparatus and allow it to drain 
and cool for at least 10 min. Remove the micro-Snyder column and rinse 
its lower joint into the concentrator tube with a minimum amount of 
cyclohexane. Adjust the extract volume to about 2 mL.
    11.3  Silica gel column cleanup for PAHs:
    11.3.1  Prepare a slurry of 10 g of activiated silica gel in 
methylene chloride and place this into a 10-mm ID chromatographic 
column. Tap the column to settle the silica gel and elute the methylene 
chloride. Add 1 to 2 cm of anhydrous sodium sulfate to the top of the 
silica gel.
    11.3.2  Preelute the column with 40 mL of pentane. The rate for all 
elutions should be about 2 mL/min. Discard the eluate and just prior to 
exposure of the sodium sulfate layer to the air, transfer the 2-mL 
cyclohexane sample extract onto the column using an additional 2 mL 
cyclohexane to complete the transfer. Just prior to exposure of the 
sodium sulfate layer to the air, add 25 mL of pentane and continue the 
elution of the column. Discard this pentane eluate.
    11.3.3  Next, elute the column with 25 mL of methylene chloride/
pentane (4+6)(V/V) into a 500-mL K-D flask equipped with a 10-mL 
concentrator tube. Concentrate the collected fraction to less than 10 mL 
as in Section 10.6. When the apparatus is cool, remove the Snyder column 
and rinse the flask and its lower joint with pentane. Proceed with HPLC 
or GC analysis.

               12. High Performance Liquid Chromatography

    12.1  To the extract in the concentrator tube, add 4 mL of 
acetonitrile and a new boiling chip, then attach a two-ball micro-Snyder 
column. Concentrate the solvent as in Section 10.6, except set the water 
bath at 95 to 100  deg.C. When the apparatus is cool, remove the micro-
Snyder column and rinse its lower joint into the concentrator tube with 
about 0.2 mL of acetonitrile. Adjust the extract volume to 1.0 mL.
    12.2  Table 1 summarizes the recommended operating conditions for 
the HPLC. Included in this table are retention times, capacity factors, 
and MDL that can be achieved under

[[Page 151]]

these conditions. The UV detector is recommended for the determination 
of naphthalene, acenaphthylene, acenapthene, and fluorene and the 
fluorescence detector is recommended for the remaining PAHs. Examples of 
the separations achieved by this HPLC column are shown in Figures 1 and 
2. Other HPLC columns, chromatographic conditions, or detectors may be 
used if the requirements of Section 8.2 are met.
    12.3  Calibrate the system daily as described in Section 7.
    12.4  If the internal standard calibration procedure is being used, 
the internal standard must be added to the sample extract and mixed 
thoroughly immediately before injection into the instrument.
    12.5  Inject 5 to 25 L of the sample extract or standard 
into the HPLC using a high pressure syringe or a constant volume sample 
injection loop. Record the volume injected to the nearest 0.1 
L, and the resulting peak size in area or peak height units. 
Re-equilibrate the HPLC column at the initial gradient conditions for at 
least 10 min between injections.
    12.6  Identify the parameters in the sample by comparing the 
retention time of the peaks in the sample chromatogram with those of the 
peaks in standard chromatograms. The width of the retention time window 
used to make identifications should be based upon measurements of actual 
retention time variations of standards over the course of a day. Three 
times the standard deviation of a retention time for a compound can be 
used to calculate a suggested window size; however, the experience of 
the analyst should weigh heavily in the interpretation of chromatograms.
    12.7  If the response for a peak exceeds the working range of the 
system, dilute the extract with acetonitrile and reanalyze.
    12.8  If the measurement of the peak response is prevented by the 
presence of interferences, further cleanup is required.

                         13. Gas Chromatography

    13.1  The packed column GC procedure will not resolve certain 
isomeric pairs as indicated in Section 1.3 and Table 2. The liquid 
chromatographic procedure (Section 12) must be used for these 
parameters.
    13.2  To achieve maximum sensitivity with this method, the extract 
must be concentrated to 1.0 mL. Add a clean boiling chip to the 
methylene chloride extract in the concentrator tube. Attach a two-ball 
micro-Snyder column. Prewet the micro-Snyder column by adding about 0.5 
mL of methylene chloride to the top. Place the micro-K-D apparatus on a 
hot water bath (60 to 65  deg.C) so that the concentrator tube is 
partially immersed in the hot water. Adjust the vertical position of the 
apparatus and the water temperature as required to complete the 
concentration in 5 to 10 min. At the proper rate of distillation the 
balls will actively chatter but the chambers will not flood. When the 
apparent volume of liquid reaches 0.5 mL, remove the K-D apparatus and 
allow it to drain and cool for at least 10 min. Remove the micro-Snyder 
column and rinse its lower joint into the concentrator tube with a 
minimum amount of methylene chloride. Adjust the final volume to 1.0 mL 
and stopper the concentrator tube.
    13.3  Table 2 summarizes the recommended operating conditions for 
the gas chromatograph. Included in this table are retention times that 
were obtained under these conditions. An example of the separations 
achieved by this column is shown in Figure 3. Other packed or capillary 
(open-tubular) columns, chromatographic conditions, or detectors may be 
used if the requirements of Section 8.2 are met.
    13.4  Calibrate the gas chromatographic system daily as described in 
Section 7.
    13.5  If the internal standard calibration procedure is being used, 
the internal standard must be added to the sample extract and mixed 
thoroughly immediately before injection into the gas chromatograph.
    13.6  Inject 2 to 5 L of the sample extract or standard 
into the gas chromatograph using the solvent-flush technique.\10\ 
Smaller (1.0 L) volumes may be injected if automatic devices 
are employed. Record the volume injected to the nearest 0.05 L, 
and the resulting peak size in area or peak height units.
    13.7  Identify the parameters in the sample by comparing the 
retention times of the peaks in the sample chromatogram with those of 
the peaks in standard chromatograms. The width of the retention time 
window used to make identifications should be based upon measurements of 
actual retention time variations of standards over the course of a day. 
Three times the standard deviation of a retention time for a compound 
can be used to calculate a suggested window size; however, the 
experience of the analyst should weigh heavily in the interpretation of 
chromatograms.
    13.8  If the response for a peak exceeds the working range of the 
system, dilute the extract and reanalyze.
    13.9  If the measurement of the peak response is prevented by the 
presence of interferences, further cleanup is required.

                            14. Calculations

    14.1  Determine the concentration of individual compounds in the 
sample.
    14.1.1  If the external standard calibration procedure is used, 
calculate the amount of material injected from the peak response using 
the calibration curve or calibration factor determined in Section 7.2.2. 
The concentration in the sample can be calculated from Equation 2.

[[Page 152]]



                                                                                                                
                                                                           (A)(Vt)                              
                                        Concentration (g/  = -----------------                         
                                                    L)                     (Vi)(Vs)                             
                                                                                                                

                                                              Equation 2
where:
    A=Amount of material injected (ng).
    Vi=Volume of extract injected (L).
    Vt=Volume of total extract (L).
    Vs=Volume of water extracted (mL).

    13.1.2  If the internal standard calibration procedure is used, 
calculate the concentration in the sample using the response factor (RF) 
determined in Section 7.3.2 and Equation 3.

                                                                                                                
                                                                           (As)(Is)                             
                                        Concentration (g/  = -----------------                         
                                                    L)                  (Ais)(RF)(Vo)                           
                                                                                                                

                                                              Equation 3
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Is=Amount of internal standard added to each extract 
(g).
    Vo=Volume of water extracted (L).

    14.2  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

                         15. Method Performance

    15.1  The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the value is above zero.\1\ The MDL concentrations 
listed in Table 1 were obtained using reagent water.\11\ Similar results 
were achieved using representative wastewaters. MDL for the GC approach 
were not determined. The MDL actually achieved in a given analysis will 
vary depending on instrument sensitivity and matrix effects.
    15.2  This method has been tested for linearity of spike recovery 
from reagent water and has been demonstrated to be applicable over the 
concentration range from 8  x  MDL to 800  x  MDL\11\ with the following 
exception: benzo(ghi)perylene recovery at 80  x  and 800  x  MDL were 
low (35% and 45%, respectively).
    15.3  This method was tested by 16 laboratories using reagent water, 
drinking water, surface water, and three industrial wastewaters spiked 
at six concentrations over the range 0.1 to 425 g/L.\12\ Single 
operator precision, overall precision, and method accuracy were found to 
be directly related to the concentration of the parameter and 
essentially independent of the sample matrix. Linear equations to 
describe these relationships are presented in Table 4.

                               References

    1. 40 CFR part 136, appendix B.
    2. ``Determination of Polynuclear Aromatic Hydrocarbons in 
Industrial and Municipal Wastewaters,'' EPA 600/4-82-025, National 
Technical Information Service, PB82-258799, Springfield, Virginia 22161, 
June 1982.
    3. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard 
Practices for Preparation of Sample Containers and for Preservation of 
Organic Constituents,'' American Society for Testing and Materials, 
Philadelphia.
    4. ``Carcinogens--Working With Carcinogens,'' Department of Health, 
Education, and Welfare, Public Health Service, Center for Disease 
Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    5. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR 
part 1910), Occupational Safety and Health Administration, OSHA 2206 
(Revised, January 1976).
    6. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent 
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44 
used in the equation in Section 8.3.3 is two times the value 1.22 
derived in this report.)
    8. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard 
Practices for Sampling Water,'' American Society for Testing and 
Materials, Philadelphia.
    9. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for 
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory, Cincinnati, Ohio 45268, March 1979.
    10. Burke, J.A. ``Gas Chromatography for Pesticide Residue Analysis; 
Some Practical Aspects,'' Journal of the Association of Official 
Analytical Chemists, 48, 1037 (1965).
    11. Cole, T., Riggin, R., and Glaser, J. ``Evaluation of Method 
Detection Limits and Analytical Curve for EPA Method 610--PNAs,'' 
International Symposium on Polynuclear Aromatic Hydrocarbons, 5th, 
Battelle's Columbus Laboratories, Columbus, Ohio (1980).
    12. ``EPA Method Study 20, Method 610 (PNA's),'' EPA 600/4-84-063, 
National Technical Information Service, PB84-211614, Springfield, 
Virginia 22161, June 1984.

[[Page 153]]



  Table 1--High Performance Liquid Chromatography Conditions and Method 
                            Detection Limits                            
------------------------------------------------------------------------
                                                               Method   
                                       Retention   Column     detection 
              Parameter                   time    capacity      limit   
                                         (min)     factor   (g/
                                                     (k)        L) a    
------------------------------------------------------------------------
Naphthalene..........................       16.6      12.2       1.8    
Acenaphthylene.......................       18.5      13.7       2.3    
Acenaphthene.........................       20.5      15.2       1.8    
Fluorene.............................       21.2      15.8       0.21   
Phenanthrene.........................       22.1      16.6       0.64   
Anthracene...........................       23.4      17.6       0.66   
Fluoranthene.........................       24.5      18.5       0.21   
Pyrene...............................       25.4      19.1       0.27   
Benzo(a)anthracene...................       28.5      21.6       0.013  
Chrysene.............................       29.3      22.2       0.15   
Benzo(b)fluoranthene.................       31.6      24.0       0.018  
Benzo(k)fluoranthene.................       32.9      25.1       0.017  
Benzo(a)pyrene.......................       33.9      25.9       0.023  
Dibenzo(a,h)anthracene...............       35.7      27.4       0.030  
Benzo(ghi)perylene...................       36.3      27.8       0.076  
Indeno(1,2,3-cd)pyrene...............       37.4      28.7       0.043  
------------------------------------------------------------------------
 AAAHPLC column conditions: Reverse phase HC-ODS Sil-X, 5 micron        
  particle size, in a 25 cm  x  2.6 mm ID stainless steel column.       
  Isocratic elution for 5 min. using acetonitrile/water (4+6), then     
  linear gradient elution to 100% acetonitrile over 25 min. at 0.5 mL/  
  min flow rate. If columns having other internal diameters are used,   
  the flow rate should be adjusted to maintain a linear velocity of 2 mm/
  sec.                                                                  
a The MDL for naphthalene, acenaphthylene, acenaphthene, and fluorene   
  were determined using a UV detector. All others were determined using 
  a fluorescence detector.                                              


       Table 2--Gas Chromatographic Conditions and Retention Times      
------------------------------------------------------------------------
                                                               Retention
                          Parameter                           time (min)
------------------------------------------------------------------------
Naphthalene.................................................         4.5
Acenaphthylene..............................................        10.4
Acenaphthene................................................        10.8
Fluorene....................................................        12.6
Phenanthrene................................................        15.9
Anthracene..................................................        15.9
Fluoranthene................................................        19.8
Pyrene......................................................        20.6
Benzo(a)anthracene..........................................        24.7
Chrysene....................................................        24.7
Benzo(b)fluoranthene........................................        28.0
Benzo(k)fluoranthene........................................        28.0
Benzo(a)pyrene..............................................        29.4
Dibenzo(a,h)anthracene......................................        36.2
Indeno(1,2,3-cd)pyrene......................................        36.2
Benzo(ghi)perylene..........................................        38.6
------------------------------------------------------------------------
GC Column conditions: Chromosorb W-AW-DCMS (100/120 mesh) coated with 3%
  OV-17 packed in a 1.8 x 2 mm ID glass column with nitrogen carrier gas
  at 40 mL/min. flow rate. Column temperature was held at 100 C for 4   
  min., then programmed at 8 C/min. to a final hold at 280 C.           


                                   Table 3--QC Acceptance Criteria--Method 610                                  
----------------------------------------------------------------------------------------------------------------
                                                                                        Range for X             
                                                            Test conc.    Limit for s  (g/   Range for 
                        Parameter                          (g/  (g/       L)        P, Ps (%) 
                                                                L)            L)                                
----------------------------------------------------------------------------------------------------------------
Acenaphthene.............................................           100          40.3       D-105.7        D-124
Acenaphthylene...........................................           100          45.1    22.1-112.1        D-139
Anthracene...............................................           100          28.7    11.2-112.3        D-126
Benzo(a)anthracene.......................................            10           4.0      3.1-11.6       12-135
Benzo(a)pyrene...........................................            10           4.0      0.2-11.0        D-128
Benzo(b)fluor-anthene....................................            10           3.1      1.8-13.8        6-150
Benzo(ghi)perylene.......................................            10           2.3        D-10.7        D-116
Benzo(k)fluo-ranthene....................................             5           2.5         D-7.0        D-159
Chrysene.................................................            10           4.2        D-17.5        D-199
Dibenzo(a,h)an-thracene..................................            10           2.0      0.3-10.0        D-110
Fluoranthene.............................................            10           3.0      2.7-11.1       14-123
Fluorene.................................................           100          43.0         D-119        D-142
Indeno(1,2,3-cd)pyrene...................................            10           3.0      1.2-10.0        D-116
Naphthalene..............................................           100          40.7    21.5-100.0        D-122
Phenanthrene.............................................           100          37.7     8.4-133.7        D-155
Pyrene...................................................            10           3.4      1.4-12.1        D-140
----------------------------------------------------------------------------------------------------------------
s=Standard deviation of four recovery measurements, in g/L (Section 8.2.4).                            
X=Average recovery for four recovery measurements, in g/L (Section 8.2.4).                             
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).                                                 
D=Detected; result must be greater than zero.                                                                   
                                                                                                                
Note: These criteria are based directly upon the method performance data in Table 4. Where necessary, the limits
  for recovery have been broadened to assure applicability of the limits to concentrations below those used to  
  develop Table 4.                                                                                              


                Table 4--Method Accuracy and Precision as Functions of Concentration--Method 610                
----------------------------------------------------------------------------------------------------------------
                                                                   Accuracy, as   Single analyst      Overall   
                            Parameter                               recovery, X    precision, sr   precision, S 
                                                                  (g/L)  (g/L)  (g/L)
----------------------------------------------------------------------------------------------------------------
Acenaphthene....................................................    0.52C + 0.54    0.39X + 0.76    0.53X + 1.32
Acenaphthylene..................................................    0.69C - 1.89    0.36X + 0.29    0.42X + 0.52
Anthracene......................................................    0.63C - 1.26    0.23X + 1.16    0.41X + 0.45
Benzo(a)anthracene..............................................    0.73C + 0.05    0.28X + 0.04    0.34X + 0.02
Benzo(a)pyrene..................................................    0.56C + 0.01    0.38X - 0.01    0.53X - 0.01
Benzo(b)fluoranthene............................................    0.78C + 0.01    0.21X + 0.01    0.38X - 0.00
Benzo(ghi)perylene..............................................    0.44C + 0.30    0.25X + 0.04    0.58X + 0.10
Benzo(k)fluoranthene............................................    0.59C + 0.00    0.44X - 0.00    0.69X + 0.01
Chrysene........................................................    0.77C - 0.18    0.32X - 0.18    0.66X - 0.22
Dibenzo(a,h)anthracene..........................................    0.41C + 0.11    0.24X + 0.02    0.45X + 0.03

[[Page 154]]

                                                                                                                
Fluoranthene....................................................    0.68C + 0.07    0.22X + 0.06    0.32X + 0.03
Fluorene........................................................    0.56C - 0.52    0.44X - 1.12    0.63X - 0.65
Indeno(1,2,3-cd)pyrene..........................................    0.54C + 0.06    0.29X + 0.02    0.42X + 0.01
Naphthalene.....................................................    0.57C - 0.70    0.39X - 0.18    0.41X + 0.74
Phenanthrene....................................................    0.72C - 0.95    0.29X + 0.05    0.47X - 0.25
Pyrene..........................................................    0.69C - 0.12    0.25X + 0.14   0.42X - 0.00 
----------------------------------------------------------------------------------------------------------------
X=Expected recovery for one or more measurements of a sample containing a concentration of C, in g/L.  
sr=Expected single analyst standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
S=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
C=True value for the concentration, in g/L.                                                            
X=Average recovery found for measurements of samples containing a concentration of C, in g/L.          


[[Page 155]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.031


[[Page 156]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.032


[[Page 157]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.033


[[Page 158]]

                         Method 611--Haloethers

                        1. Scope and Application

    1.1  This method covers the determination of certain haloethers. The 
following parameters can be determined by this method:

------------------------------------------------------------------------
                   Parameter                     STORET No.    CAS No.  
------------------------------------------------------------------------
Bis(2-chloroethyl) ether......................        34273     111-44-4
Bis(2-chloroethoxy) methane...................        34278     111-91-1
Bis(2-chloroisopropyl) ether..................        34283     108-60-1
4-Bromophenyl phenyl ether....................        34636     101-55-3
4-Chlorophenyl phenyl either..................        34641    7005-72-3
------------------------------------------------------------------------

    1.2  This is a gas chromatographic (GC) method applicable to the 
determination of the compounds listed above in municipal and industrial 
discharges as provided under 40 CFR 136.1. When this method is used to 
analyze unfamiliar samples for any or all of the compounds above, 
compound identifications should be supported by at least one additional 
qualitative technique. This method describes analytical conditions for a 
second gas chromatographic column that can be used to confirm 
measurements made with the primary column. Method 625 provides gas 
chromatograph/mass spectrometer (GC/MS) conditions appropriate for the 
qualitative and quantitative confirmation of results for all of the 
parameters listed above, using the extract produced by this method.
    1.3  The method detection limit (MDL, defined in Section 14.1)1 
for each parameter is listed in Table 1. The MDL for a specific 
wastewater may differ from those listed, depending upon the nature of 
interferences in the sample matrix.
    1.4  The sample extraction and concentration steps in this method 
are essentially the same as in Methods 606, 608, 609, and 612. Thus, a 
single sample may be extracted to measure the parameters included in the 
scope of each of these methods. When cleanup is required, the 
concentration levels must be high enough to permit selecting aliquots, 
as necessary, to apply appropriate cleanup procedures. The analyst is 
allowed the latitude, under Section 12, to select chromatographic 
conditions appropriate for the simultaneous measurement of combinations 
of these parameters.
    1.5  Any modification of this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5.
    1.6  This method is restricted to use by or under the supervision of 
analysts experienced in the use of a gas chromatograph and in the 
interpretation of gas chromatograms. Each analyst must demonstrate the 
ability to generate acceptable results with this method using the 
procedure described in Section 8.2.

                          2. Summary of Method

    2.1  A measured volume of sample, approximately 1-L, is extracted 
with methylene chloride using a separatory funnel. The methylene 
chloride extract is dried and exchanged to hexane during concentration 
to a volume of 10 mL or less. The extract is separated by gas 
chromatography and the parameters are then measured with a halide 
specific detector.2
    2.2  The method provides a Florisil column cleanup procedure to aid 
in the elimination of interferences that may be encountered.

                            3. Interferences

    3.1  Method interferences may be caused by contaminants in solvents, 
reagents, glassware, and other sample processing hardware that lead to 
discrete artifacts and/or elevated baselines in gas chromatograms. All 
of these materials must be routinely demonstrated to be free from 
interferences under the conditions of the analysis by running laboratory 
reagent blanks as described in Section 8.1.3.
    3.1.1  Glassware must be scrupulously cleaned.3 Clean all 
glassware as soon as possible after use by rinsing with the last solvent 
used in it. Solvent rinsing should be followed be detergent washing with 
hot water, and rinses with tap water and distilled water. The glassware 
should then be drained dry, and heated in a muffle furnace at 400  deg.C 
for 15 to 30 min. Some thermally stable materials, such a PCBs, may not 
be eliminated by this treatment. Solvent rinses with acetone and 
pesticide quality hexane may be substituted for the muffle furnace 
heating. Thorough rinsing with such solvents usually eliminates PCB 
interference. Volumetric ware should not be heated in a muffle furnace. 
After drying and cooling, glassware should be sealed and stored in a 
clean environment to prevent any accumulation of dust or other 
contaminants. Store inverted or capped with aluminum foil.
    3.1.2  The use of high purity reagents and solvents helps to 
minimize interference problems. Purification of solvents by distillation 
in all-glass systems may be required.
    3.2  Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary 
considerably from source to source, depending upon the nature and 
diversity of the industrial complex or municipality being sampled. The 
cleanup procedure in Section 11 can be used to overcome many of these 
interferences, but unique samples may require additional cleanup 
approaches to achieve the MDL listed in Table 1.
    3.3  Dichlorobenzenes are known to coelute with haloethers under 
some gas chromatographic conditions. If these materials are present 
together in a sample, it may be necessary to analyze the extract

[[Page 159]]

with two different column packings to completely resolve all of the 
compounds.

                                4. Safety

    4.1  The toxicity or carcinogenicity of each reagent used in this 
method has not been precisely defined; however, each chemical compound 
should be treated as a potential health hazard. From this viewpoint, 
exposure to these chemicals must be reduced to the lowest possible level 
by whatever means available. The laboratory is responsible for 
maintaining a current awareness file of OSHA regulations regarding the 
safe handling of the chemicals specified in this method. A reference 
file of material data handling sheets should also be made available to 
all personnel involved in the chemical analysis. Additional references 
to laboratory safety are available and have been identified \4\-\6\ 
for the information of the analyst.

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete or composite sampling.
    5.1.1  Grab sample bottle--1-L or 1-qt, amber glass, fitted with a 
screw cap lined with Teflon. Foil may be substituted for Teflon if the 
sample is not corrosive. If amber bottles are not available, protect 
samples from light. The bottle and cap liner must be washed, rinsed with 
acetone or methylene chloride, and dried before use to minimize 
contamination.
    5.1.2  Automatic sampler (optional)--The sampler must incorporate 
glass sample containers for the collection of a minimum of 250 mL of 
sample. Sample containers must be kept refrigerated at 4  deg.C and 
protected from light during compositing. If the sampler uses a 
peristaltic pump, a minimum length of compressible silicone rubber 
tubing may be used. Before use, however, the compressible tubing should 
be thoroughly rinsed with methanol, followed by repeated rinsings with 
distilled water to minimize the potential for contamination of the 
sample. An integrating flow meter is required to collect flow 
proportional composites.
    5.2  Glassware (All specifications are suggested. Catalog numbers 
are included for illustration only.):
    5.2.1  Separatory funnel--2-L, with Teflon stopcock.
    5.2.2  Drying column--Chromatographic column, approximately 400 mm 
long x 19 mm ID, with coarse frit filter disc.
    5.2.3  Chromatographic column--400 mm long x 19 mm ID, with Teflon 
stopcock and coarse frit filter disc at bottom (Kontes K-420540-0224 or 
equivalent).
    5.2.4  Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes 
K-570050-1025 or equivalent). Calibration must be checked at the volumes 
employed in the test. Ground glass stopper is used to prevent 
evaporation of extracts.
    5.2.5  Evaporative flask, Kuderna-Danish--500-mL (Kontes K-570001-
0500 or equivalent). Attach to concentrator tube with springs.
    5.2.6  Snyder column, Kuderna-Danish--Three-ball macro (Kontes K-
503000-0121 or equivalent).
    5.2.7  Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
    5.3  Boiling chips--Approximately 10/40 mesh. Heat to 400  deg.C for 
30 min or Soxhlet extract with methylene chloride.
    5.4  Water bath--Heated, with concentric ring cover, capable of 
temperature control (2 deg.C). The bath should be used in a 
hood.
    5.5  Balance--Analytical, capable of accurately weighing 0.0001 g.
    5.6  Gas chromatograph--An analytical system complete with 
temperature programmable gas chromatograph suitable for on-column 
injection and all required accessories including syringes, analytical 
columns, gases, detector, and strip-chart recorder. A data system is 
recommended for measuring peak areas.
    5.6.1  Column 1--1.8 m long x 2 mm ID glass, packed with 3% SP-1000 
on Supelcoport (100/120 mesh) or equivalent. This column was used to 
develop the method performance statements in Section 14. Guidelines for 
the use of alternate column packings are provided in Section 12.1.
    5.6.2  Column 2--1.8 m long x 2 mm ID glass, packed with 2,6-
diphenylene oxide polymer (60/80 mesh), Tenax, or equivalent.
    5.6.3  Detector--Halide specific detector: electrolytic conductivity 
or microcoulometric. These detectors have proven effective in the 
analysis of wastewaters for the parameters listed in the scope (Section 
1.1). The Hall conductivity detector was used to develop the method 
performance statements in Section 14. Guidelines for the use of 
alternate detectors are provided in Section 12.1. Although less 
selective, an electron capture detector is an acceptable alternative.

                               6. Reagents

    6.1  Reagent water--Reagent water is defined as a water in which an 
interferent is not observed at the MDL of the parameters of interest.
    6.2  Sodium thiosulfate--(ACS) Granular.
    6.3  Acetone, hexane, methanol, methylene chloride, petroleum ether 
(boiling range 30-60  deg.C)--Pesticide quality or equivalent.
    6.4  Sodium sulfate--(ACS) Granular, anhydrous. Purify by heating at 
400  deg.C for 4 h in a shallow tray.
    6.5  Florisil--PR Grade (60/100 mesh). Purchase activated at 1250 
deg.F and store in the dark in glass containers with ground glass 
stoppers or foil-lined screw caps. Before use, activate each batch at 
least 16 h at 130  deg.C in a foil-covered glass container and allow to 
cool.

[[Page 160]]

    6.6  Ethyl ether--Nanograde, redistilled in glass if necessary.
    6.6.1  Ethyl ether must be shown to be free of peroxides before it 
is used as indicated by EM Laboratories Quant test strips. (Available 
from Scientific Products Co., Cat. No. P1126-8, and other suppliers.)
    6.6.2  Procedures recommended for removal of peroxides are provided 
with the test strips. After cleanup, 20 mL of ethyl alcohol preservative 
must be added to each liter of ether.
    6.7  Stock standard solutions (1.00 g/L)--Stock 
standard solutions can be prepared from pure standard materials or 
purchased as certified solutions.
    6.7.1  Prepare stock standard solutions by accurately weighing about 
0.0100 g of pure material. Dissolve the material in acetone and dilute 
to volume in a 10-mL volumetric flask. Larger volumes can be used at the 
convenience of the analyst. When compound purity is assayed to be 96% or 
greater, the weight can be used without correction to calculate the 
concentration of the stock standard. Commercially prepared stock 
standards can be used at any concentration if they are certified by the 
manufacturer or by an independent source.
    6.7.2  Transfer the stock standard solutions into Teflon-sealed 
screw-cap bottles. Store at 4  deg.C and protect from light. Stock 
standard solutions should be checked frequently for signs of degradation 
or evaporation, especially just prior to preparing calibration standards 
from them.
    6.7.3  Stock standard solutions must be replaced after six months, 
or sooner if comparison with check standards indicates a problem.
    6.8  Quality control check sample concentrate--See Section 8.2.1.

                             7. Calibration

    7.1  Establish gas chromatographic operating conditions equivalent 
to those given in Table 1. The gas chromatographic system can be 
calibrated using the external standard technique (Section 7.2) or the 
internal standard technique (Section 7.3).
    7.2  External standard calibration procedure:
    7.2.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask and diluting to volume 
with hexane. One of the external standards should be at a concentration 
near, but above, the MDL (Table 1) and the other concentrations should 
correspond to the expected range of concentrations found in real samples 
or should define the working range of the detector.
    7.2.2  Using injections of 2 to 5 L, analyze each 
calibration standard according to Section 12 and tabulate peak height or 
area responses against the mass injected. The results can be used to 
prepare a calibration curve for each compound. Alternatively, if the 
ratio of response to amount injected (calibration factor) is a constant 
over the working range (<10% relative standard deviation, RSD), 
linearity through the origin can be assumed and the average ratio or 
calibration factor can be used in place of a calibration curve.
    7.3  Internal standard calibration procedure--To use this approach, 
the analyst must select one or more internal standards that are similar 
in analytical behavior to the compounds of interest. The analyst must 
further demonstrate that the measurement of the internal standard is not 
affected by method or matrix interferences. Because of these 
limitations, no internal standard can be suggested that is applicable to 
all samples.
    7.3.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask. To each calibration 
standard, add a known constant amount of one or more internal standards, 
and dilute to volume with hexane. One of the standards should be at a 
concentration near, but above, the MDL and the other concentrations 
should correspond to the expected range of concentrations found in real 
samples or should define the working range of the detector.
    7.3.2  Using injections of 2 to 5 L, analyze each 
calibration standard according to Section 12 and tabulate peak height or 
area responses against concentration for each compound and internal 
standard. Calculate response factors (RF) for each compound using 
Equation 1.

                                                                        
                                            (As)(Cis)                   
                                   RF=   --------------                 
                                            (Ais)(Cs)                   
                                                                        

                                                              Equation 1
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Cis=Concentration of the internal standard (g/L).
    Cs=Concentration of the parameter to be measured (g/
L).
If the RF value over the working range is a constant (< 10% RSD), the RF 
can be assumed to be invariant and the average RF can be used for 
calculations. Alternatively, the results can be used to plot a 
calibration curve of response ratios, As/Ais, vs. RF.
    7.4  The working calibration curve, calibration factor, or RF must 
be verified on each working day by the measurement of one

[[Page 161]]

or more calibration standards. If the response for any parameter varies 
from the predicted response by more than 15%, a new 
calibration curve must be prepared for that compound.
    7.5  The cleanup procedure in Section 11 utilizes Florisil column 
chromatography. Florisil from different batches or sources may vary in 
adsorptive capacity. To standardize the amount of Florisil which is 
used, the use of lauric acid value \7\ is suggested. The referenced 
procedure determines the adsorption from hexane solution of lauric acid 
(mg) per g of Florisil. The amount of Florisil to be used for each 
column is calculated by dividing 110 by this ratio and multiplying by 20 
g.
    7.6  Before using any cleanup procedure, the analyst must process a 
series of calibration standards through the procedure to validate 
elution patterns and the absence of interferences from the reagents.

                           8. Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality control program. The minimum requirements of this program 
consist of an initial demonstration of laboratory capability and an 
ongoing analysis of spiked samples to evaluate and document data 
quality. The laboratory must maintain records to document the quality of 
data that is generated. Ongoing data quality checks are compared with 
established performance criteria to determine if the results of analyses 
meet the performance characteristics of the method. When results of 
sample spikes indicate atypical method performance, a quality control 
check standard must be analyzed to confirm that the measurements were 
performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occurring in 
chromatography, the analyst is permitted certain options (detailed in 
Sections 10.4, 11.1, and 12.1) to improve the separations or lower the 
cost of measurements. Each time such a modification is made to the 
method, the analyst is required to repeat the procedure in Section 8.2.
    8.1.3  Before processing any samples, the analyst must analyze a 
reagent water blank to demonstrate that interferences from the 
analytical system and glassware are under control. Each time a set of 
samples is extracted or reagents are changed, a reagent water blank must 
be processed as a safeguard against laboratory contamination.
    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 10% of all samples to monitor and evaluate laboratory data 
quality. This procedure is described in Section 8.3.
    8.1.5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 10% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.5.
    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality control (QC) check sample concentrate is required 
containing each parameter of interest at a concentration of 100 
g/mL in acetone. The QC check sample concentrate must be 
obtained from the U.S. Environmental Protection Agency, Environmental 
Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If 
not available from that source, the QC check sample concentrate must be 
obtained from another external source. If not available from either 
source above, the QC check sample concentrate must be prepared by the 
laboratory using stock standards prepared independently from those used 
for calibration.
    8.2.2  Using a pipet, prepare QC check samples at a concentration of 
100 g/L by adding 1.00 mL of QC check sample concentrate to 
each of four 1-L aliquots of reagent water.
    8.2.3  Analyze the well-mixed QC check samples according to the 
method beginning in Section 10.
    8.2.4  Calculate the average recovery (X) in g/L, and the 
standard deviation of the recovery (s) in g/L, for each 
parameter using the four results.
    8.2.5  For each parameter compare s and X with the corresponding 
acceptance criteria for precision and accuracy, respectively, found in 
Table 2. If s and X for all parameters of interest meet the acceptance 
criteria, the system performance is acceptable and analysis of actual 
samples can begin. If any individual s exceeds the precision limit or 
any individual X falls outside the range for accuracy, the system 
performance is unacceptable for that parameter. Locate and correct the 
source of the problem and repeat the test for all parameters of interest 
beginning with Section 8.2.2.
    8.3  The laboratory must, on an ongoing basis, spike at least 10% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing one to ten samples per month, at least one 
spiked sample per month is required.
    8.3.1.  The concentration of the spike in the sample should be 
determined as follows:

[[Page 162]]

    8.3.1.1  If, as in compliance monitoring, the concentration of a 
specific parameter in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of a specific parameter in the sample 
is not being checked against a limit specific to that parameter, the 
spike should be at 100 g/L or 1 to 5 times higher than the 
background concentration determined in Section 8.3.2, whichever 
concentration would be larger.
    8.3.1.3  If it is impractical to determine background levels before 
spiking (e.g., maximum holding times will be exceeded), the spike 
concentration should be (1) the regulatory concentration limit, if any; 
or, if none (2) the larger of either 5 times higher than the expected 
background concentration or 100 g/L.
    8.3.2  Analyze one sample aliquot to determine the background 
concentration (B) of each parameter. If necessary, prepare a new QC 
check sample concentrate (Section 8.2.1) appropriate for the background 
concentrations in the sample. Spike a second sample aliquot with 1.0 mL 
of the QC check sample concentrate and analyze it to determine the 
concentration after spiking (A) of each parameter. Calculate each 
percent recovery (P) as 100(A-B)%/T, where T is the known true value of 
the spike.
    8.3.3  Compare the percent recovery (P) for each parameter with the 
corresponding QC acceptance criteria found in Table 2. These acceptance 
criteria were calculated to include an allowance for error in 
measurement of both the background and spike concentrations, assuming a 
spike to background ratio of 5:1. This error will be accounted for to 
the extent that the analyst's spike to background ratio approaches 
5:1.\8\ If spiking was performed at a concentration lower than 100 
g/L, the analyst must use either the QC acceptance criteria in 
Table 2, or optional QC acceptance criteria calculated for the specific 
spike concentration. To calculate optional acceptance criteria for the 
recovery of a parameter: (1) Calculate accuracy (X') using the equation 
in Table 3, substituting the spike concentration (T) for C; (2) 
calculate overall precision (S') using the equation in Table 3, 
substituting X' for X; (3) calculate the range for recovery at the spike 
concentration as (100 X'/T)2.44(100 S'/T)%.\8\
    8.3.4  If any individual P falls outside the designated range for 
recovery, that parameter has failed the acceptance criteria. A check 
standard containing each parameter that failed the criteria must be 
analyzed as described in Section 8.4.
    8.4  If any parameter fails the acceptance criteria for recovery in 
Section 8.3, a QC check standard containing each parameter that failed 
must be prepared and analyzed.

    Note: The frequency for the required analysis of a QC check standard 
will depend upon the number of parameters being simultaneously tested, 
the complexity of the sample matrix, and the performance of the 
laboratory.

    8.4.1  Prepare the QC check standard by adding 1.0 m/L of QC check 
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The 
QC check standard needs only to contain the parameters that failed 
criteria in the test in Section 8.3.
    8.4.2  Analyze the QC check standard to determine the concentration 
measured (A) of each parameter. Calculate each percent recovery 
(Ps) as 100 (A/T)%, where T is the true value of the standard 
concentration.
    8.4.3  Compare the percent recovery (Ps) for each parameter 
with the corresponding QC acceptance criteria found in Table 2. Only 
parameters that failed the test in Section 8.3 need to be compared with 
these criteria. If the recovery of any such parameter falls outside the 
designated range, the laboratory performance for that parameter is 
judged to be out of control, and the problem must be immediately 
identified and corrected. The analytical result for that parameter in 
the unspiked sample is suspect and may not be reported for regulatory 
compliance purposes.
    8.5  As part of the QC program for the laboratory, method accuracy 
for wastewater samples must be assessed and records must be maintained. 
After the analysis of five spiked wastewater samples as in Section 8.3, 
calculate the average percent recovery (P) and the standard deviation of 
the percent recovery (sp). Express the accuracy assessment as a 
percent recovery interval from P-2sp to P+2sp. If P=90% and 
sp=10%, for example, the accuracy interval is expressed as 70-110%. 
Update the accuracy assessment for each parameter on a regular basis 
(e.g. after each five to ten new accuracy measurements).
    8.6  It is recommended that the laboratory adopt additional quality 
assurance practices for use with this method. The specific practices 
that are most productive depend upon the needs of the laboratory and the 
nature of the samples. Field duplicates may be analyzed to assess the 
precision of the environmental measurements. When doubt exists over the 
identification of a peak on the chromatogram, confirmatory techniques 
such as gas chromatography with a dissimilar column, specific element 
detector, or mass spectrometer must be used. Whenever possible, the 
laboratory should analyze standard reference materials and participate 
in relevant performance evaluation studies.

[[Page 163]]

            9. Sample Collection, Preservation, and Handling

    9.1  Grab samples must be collected in glass containers. 
Conventional sampling practices9 should be followed, except that 
the bottle must not be prerinsed with sample before collection. 
Composite samples should be collected in refrigerated glass containers 
in accordance with the requirements of the program. Automatic sampling 
equipment must be as free as possible of Tygon tubing and other 
potential sources of contamination.
    9.2  All samples must be iced or refrigerated at 4 deg.C from the 
time of collection until extraction. Fill the sample bottles and, if 
residual chlorine is present, add 80 mg of sodium thiosulfate per liter 
of sample and mix well. EPA Methods 330.4 and 330.5 may be used for 
measurement of residual chlorine.10 Field test kits are available 
for this purpose.
    9.3  All samples must be extracted within 7 days of collection and 
completely analyzed within 40 days of extraction.2

                          10. Sample Extraction

    10.1  Mark the water meniscus on the side of the sample bottle for 
later determination of sample volume. Pour the entire sample into a 2-L 
separatory funnel.
    10.2  Add 60 mL methylene chloride to the sample bottle, seal, and 
shake 30 s to rinse the inner surface. Transfer the solvent to the 
separatory funnel and extract the sample by shaking the funnel for 2 min 
with periodic venting to release excess pressure. Allow the organic 
layer to separate from the water phase for a minimum of 10 min. If the 
emulsion interface between layers is more than one-third the volume of 
the solvent layer, the analyst must employ mechanical techniques to 
complete the phase separation. The optimum technique depends upon the 
sample, but may include stirring, filtration of the emulsion through 
glass wool, centrifugation, or other physical methods. Collect the 
methylene chloride extract in a 250-mL Erlenmeyer flask.
    10.3  Add a second 60-mL volume of methylene chloride to the sample 
bottle and repeat the extraction procedure a second time, combining the 
extracts in the Erlenmeyer flask. Perform a third extraction in the same 
manner.
    10.4  Assemble a Kuderna-Danish (K-D) concentrator by attaching a 
10-mL concentrator tube to a 500-mL evaporative flask. Other 
concentration devices or techniques may be used in place of the K-D 
concentrator if the requirements of Section 8.2 are met.
    10.5  Pour the combined extract through a solvent-rinsed drying 
column containing about 10 cm of anhydrous sodium sulfate, and collect 
the extract in the K-D concentrator. Rinse the Erlenmeyer flask and 
column with 20 to 30 mL of methylene chloride to complete the 
quantitative transfer.
    10.6  Add one or two clean boiling chips to the evaporative flask 
and attach a three-ball Snyder column. Prewet the Snyder column by 
adding about 1 mL of methylene chloride to the top. Place the K-D 
apparatus on a hot water bath (60 to 65  deg.C) so that the concentrator 
tube is partially immersed in the hot water, and the entire lower 
rounded surface of the flask is bathed with hot vapor. Adjust the 
vertical position of the apparatus and the water temperature as required 
to complete the concentration in 15 to 20 min. At the proper rate of 
distillation the balls of the column will actively chatter but the 
chambers will not flood with condensed solvent. When the apparent volume 
of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain 
and cool for at least 10 min.

    Note: Some of the haloethers are very volatile and significant 
losses will occur in concentration steps if care is not exercised. It is 
important to maintain a constant gentle evaporation rate and not to 
allow the liquid volume to fall below 1 to 2 mL before removing the K-D 
apparatus from the hot water bath.

    10.7  Momentarily remove the Snyder column, add 50 mL of hexane and 
a new boiling chip, and reattach the Snyder column. Raise the 
temperature of the water bath to 85 to 90  deg.C. Concentrate the 
extract as in Section 10.6, except use hexane to prewet the column. The 
elapsed time of concentration should be 5 to 10 min.
    10.8  Remove the Snyder column and rinse the flask and its lower 
joint into the concentrator tube with 1 to 2 mL of hexane. A 5-mL 
syringe is recommended for this operation. Stopper the concentrator tube 
and store refrigerated if further processing will not be performed 
immediately. If the extract will be stored longer than two days, it 
should be transferred to a Teflon-sealed screw-cap vial. If the sample 
extract requires no further cleanup, proceed with gas chromatographic 
analysis (Section 12). If the sample requires further cleanup, proceed 
to Section 11.
    10.9  Determine the original sample volume by refilling the sample 
bottle to the mark and transferring the liquid to a 1000-mL graduated 
cylinder. Record the sample volume to the nearest 5 mL.

                       11. Cleanup and Separation

    11.1  Cleanup procedures may not be necessary for a relatively clean 
sample matrix. If particular circumstances demand the use of a cleanup 
procedure, the analyst may use the procedure below or any other 
appropriate procedure. However, the analyst first must demonstrate that 
the requirements of Section 8.2 can be met using the method as revised 
to incorporate the cleanup procedure.

[[Page 164]]

    11.2  Florisil column cleanup for haloethers:
    11.2.1  Adjust the sample extract volume to 10 mL.
    11.2.2  Place a weight of Florisil (nominally 20 g) predetermined by 
calibration (Section 7.5), into a chromatographic column. Tap the column 
to settle the Florisil and add 1 to 2 cm of anhydrous sodium sulfate to 
the top.
    11.2.3  Preelute the column with 50 to 60 mL of petroleum ether. 
Discard the eluate and just prior to exposure of the sodium sulfate 
layer to the air, quantitatively transfer the sample extract onto the 
column by decantation and subsequent petroleum ether washings. Discard 
the eluate. Just prior to exposure of the sodium sulfate layer to the 
air, begin eluting the column with 300 mL of ethyl ether/petroleum ether 
(6+94) (V/V). Adjust the elution rate to approximately 5 mL/min and 
collect the eluate in a 500-mL K-D flask equipped with a 10-mL 
concentrator tube. This fraction should contain all of the haloethers.
    11.2.4  Concentrate the fraction as in Section 10.6, except use 
hexane to prewet the column. When the apparatus is cool, remove the 
Snyder column and rinse the flask and its lower joint into the 
concentrator tube with hexane. Adjust the volume of the cleaned up 
extract to 10 mL with hexane and analyze by gas chromatography (Section 
12).

                         12. Gas Chromatography

    12.1  Table 1 summarizes the recommended operating conditions for 
the gas chromatograph. Included in this table are retention times and 
MDL that can be achieved under these conditions. Examples of the 
separations achieved by Columns 1 and 2 are shown in Figures 1 and 2, 
respectively. Other packed or capillary (open-tubular) columns, 
chromatographic conditions, or detectors may be used if the requirements 
of Section 8.2 are met.
    12.2  Calibrate the system daily as described in Section 7.
    12.3  If the internal standard calibration procedure is being used, 
the internal standard must be added to the sample extract and mixed 
thoroughly immediately before injection into the gas chromatrograph.
    12.4  Inject 2 to 5 L of the sample extract or standard 
into the gas chromatograph using the solvent-flush technique.11 
Smaller (1.0 L) volumes may be injected if automatic devices 
are employed. Record the volume injected to the nearest 0.05 L, 
the total extract volume, and the resulting peak size in area or peak 
height units.
    12.5  Identify the parameters in the sample by comparing the 
retention times of the peaks in the sample chromatogram with those of 
the peaks in standard chromatograms. The width of the retention time 
window used to make identifications should be based upon measurements of 
actual retention time variations of standards over the course of a day. 
Three times the standard deviation of a retention time for a compound 
can be used to calculate a suggested window size; however, the 
experience of the analyst should weight heavily in the interpretation of 
chromatograms.
    12.6  If the response for a peak exceeds the working range of the 
system, dilute the extract and reanalyze.
    12.7  If the measurement of the peak response is prevented by the 
presence of interferences, further cleanup is required.

                            13. Calculations

    13.1  Determine the concentration of individual compounds in the 
sample.
    13.1.1  If the external standard calibration procedure is used, 
calculate the amount of material injected from the peak response using 
the calibration curve or calibration factor determined in Section 7.2.2. 
The concentration in the sample can be calculated from Equation 2.

                                                                                                                
                                                                           (A)(Vt)                              
                                        Concentration (g/  = -----------------                         
                                                    L)                     (Vi)(Vs)                             
                                                                                                                

                                                              Equation 2
where:
    A=Amount of material injected (ng).
    Vi=Volume of extract injected (L).
    Vt=Volume of total extract (L).
    Vs=Volume of water extracted (mL).

    13.1.2  If the internal standard calibration procedure is used, 
calculate the concentration in the sample using the response factor (RF) 
determined in Section 7.3.2 and Equation 3.

                                                                                                                
                                                                           (As)(Is)                             
                                        Concentration (g/  = -----------------                         
                                                    L)                  (Ais)(RF)(Vo)                           
                                                                                                                

                                                              Equation 3
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Is=Amount of internal standard added to each extract 
(g).
    Vo=Volume of water extracted (L).

    13.2  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

                         14. Method Performance

    14.1  The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the value is above zero.1 The MDL concentrations 
listed in Table 1 were obtained using reagent water.12

[[Page 165]]

Similar results were achieved using representative wastewaters. The MDL 
actually achieved in a given analysis will vary depending on instrument 
sensitivity and matrix effects.
    14.2  This method has been tested for linearity of spike recovery 
from reagent water and has been demonstrated to be applicable over the 
concentration range from 4  x  MDL to 1000  x  MDL.12
    14.3  This method was tested by 20 laboratories using reagent water, 
drinking water, surface water, and three industrial wastewaters spiked 
at six concentrations over the range 1.0 to 626 /L.12 
Single operator precision, overall precision, and method accuracy were 
found to be directly related to the concentration of the parameter and 
essentially independent of the sample matrix. Linear equations to 
describe these relationships are presented in Table 3.

                               References

    1. 40 CFR part 136, appendix B.
    2. ``Determination of Haloethers in Industrial and Municipal 
Wastewaters,'' EPA 600/4-81-062, National Technical Information Service, 
PB81-232290, Springfield, Virginia 22161, July 1981.
    3. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard 
Practices for Preparation of Sample Containers and for Preservation of 
Organic Constitutents,'' American Society for Testing and Materials, 
Philadelphia.
    4. ``Carcinogens--Working Carcinogens, '' Department of Health, 
Education, and Welfare, Public Health Services, Center for Disease 
Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    5. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR 
part 1910), Occupational Safety and Health Administration, OSHA 2206 
(Revised, January 1976).
    6. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    7. Mills., P.A. ``Variation of Florisil Activity: Simple Method for 
Measuring Absorbent Capacity and Its Use in Standardizing Florisil 
Columns,'' Journal of the Association of Official Analytical Chemists, 
51, 29 (1968).
    8. Provost, L.P., and Elder, R.S. ``Interpretation of Percent 
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44 
used in the equation in Section 8.3.3 is two times the value 1.22 
derived in this report.)
    9. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard 
Practices for Sampling Water,'' American Society for Testing and 
Materials, Philadelphia.
    10. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for 
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory, Cincinnati, Ohio 45268, March 1979.
    11. Burke, J.A. ``Gas Chromatography for Pesticide Residue Analysis; 
Some Practical Aspects,'' Journal of the Association of Official 
Analytical Chemists, 48, 1037 (1965).
    12. ``EPA Method Study 21, Method 611, Haloethers,'' EPA 600/4-84-
052, National Technical Information Service, PB84-205939, Springfield, 
Virginia 22161, June 1984.

    Table 1--Chromatographic Conditions and Methods Detection Limits    
------------------------------------------------------------------------
                                            Retention time      Method  
                                                 (min)        detection 
                Parameters                ------------------    limit   
                                            Column   Column  (/
                                              1        2          L)    
------------------------------------------------------------------------
Bis(2-chloroisopropyl) ether.............      8.4      9.7        0.8  
Bis(2-chloroethyl) ether.................      9.3      9.1        0.3  
Bis(2-chloroethoxy) methane..............     13.1     10.0        0.5  
4-Chlorophenyl ether.....................     19.4     15.0        3.9  
4-Bromophenyl phenyl ether...............     21.2     16.2        2.3  
------------------------------------------------------------------------
 AColumn 1 conditions: Supelcoport (100/120 mesh) coated with 3% SP-1000
  packed in a 1.8 m long x 2 mm ID glass column with helium carrier gas 
  at 40 mL/min. flow rate. Column temperature held at 60 C for 2 min.   
  after injection then programmed at 8  C/min. to 230 C and held for 4  
  min. Under these conditions the retention time for Aldrin is 22.6 min.
 AColumn 2 conditions: Tenax-GC (60/80 mesh) packed in a 1.8 m long x   
  2mm ID glass column with helium carrier gas at 40 mL/min. flow rate.  
  Column temperature held at 150 C for 4 min. after injection then      
  programmed at 16 C/min. to 310 C. Under these conditions the retention
  time for Aldrin is 18.4 min.                                          


                                    Table 2--QC Acceptance Criteria--Method 611                                 
----------------------------------------------------------------------------------------------------------------
                                                                                        Range for X             
                                                            Test conc.    Limit for s  (g/   Range for 
                        Parameter                          (g/  (g/       L)          P, Ps   
                                                                L)            L)                       percent  
----------------------------------------------------------------------------------------------------------------
Bis (2-chloroethyl)ether.................................           100          26.3    26.3-136.8       11-152
Bis (2-chloroethoxy)methane..............................           100          25.7    27.3-115.0       12-128
Bis (2-chloroisopropyl)ether.............................           100          32.7    26.4-147.0        9-165
4-Bromophenyl phenyl ether...............................           100          39.3    7.6 -167.5        D-189
4-Chlorophenyl phenyl ether..............................           100          30.7    15.4-152.5        D-170
----------------------------------------------------------------------------------------------------------------
s=Standard deviation of four recovery measurements, in g/L (Section 8.2.4).                            
X=Average recovery for four recovery measurements, in g/L (Section 8.2.4).                             
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).                                                 
D=Detected; result must be greater than zero.                                                                   
                                                                                                                

[[Page 166]]

                                                                                                                
Note: These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits
  for recovery have been broadened to assure applicability of the limits to concentrations below those used to  
  develop Table 3.                                                                                              


                Table 3--Method Accuracy and Precision as Functions of Concentration--Method 611                
----------------------------------------------------------------------------------------------------------------
                                                                   Accuracy, as   Single analyst      Overall   
                            Parameter                               recovery, X    precision, sr   precision, S 
                                                                  (g/L)  (g/L)  (g/L)
----------------------------------------------------------------------------------------------------------------
Bis(2-chloroethyl) ether........................................      0.81C+0.54      0.19X+0.28      0.35X+0,36
Bis(2-chloroethoxy) methane.....................................      0.71C+0.13      0.20X+0.15      0.33X+0.11
Bis(2-chloroisopropyl) ether....................................      0.85C+1.67      0.20X+1.05      0.36X+0.79
4-Bromophenyl phenyl ether......................................      0.85C+2.55      0.25X+0.21      0.47X+0.37
4-Chlorophenyl phenyl ether.....................................      0.82C+1.97      0.18X+2.13      0.41X+0.55
----------------------------------------------------------------------------------------------------------------
X = Expected recovery for one or more measuremelts of a sample containing a concentration of C, in g/L.
sr = Expected single analyst standard deviation of measurements at an average concentration found of X, in      
  g/L.                                                                                                 
S = Expected interlaboratory standard deviation of measurements at an average concentration found of X, in      
  g/L.                                                                                                 
C =True value for the concentration, in g/L.                                                           
X = Average recovery found for measurements of samples containing a concentration of C, in g/L.        


[[Page 167]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.034


[[Page 168]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.035


[[Page 169]]

                  Method 612--Chlorinated Hydrocarbons

                        1. Scope and Application

    1.1  This method covers the determination of certain chlorinated 
hydrocarbons. The following parameters can be determined by this method:

------------------------------------------------------------------------
                                                    STORET              
                    Parameter                         No.      CAS No.  
------------------------------------------------------------------------
2-Chloronaphthalene..............................     34581      91-58-7
1,2-Dichlorobenzene..............................     34536      95-50-1
1,3-Dichlorobenzene..............................     34566     541-73-1
1,4-Dichlorobenzene..............................     34571     106-46-7
Hexachlorobenzene................................     39700     118-74-1
Hexachlorobutadiene..............................     34391      87-68-3
Hexachlorocyclopentadiene........................     34386      77-47-4
Hexachloroethane.................................     34396      67-72-1
1,2,4-Trichlorobenzene...........................     34551     120-82-1
------------------------------------------------------------------------

    1.2  This is a gas chromatographic (GC) method applicable to the 
determination of the compounds listed above in municipal and industrial 
discharges as provided under 40 CFR 136.1. When this method is used to 
analyze unfamiliar samples for any or all of the compounds above, 
compound identifications should be supported by at least one additional 
qualitative technique. This method describes a second gas 
chromatographic column that can be used to confirm measurements made 
with the primary column. Method 625 provides gas chromatograph/mass 
spectrometer (GC/MS) conditions appropriate for the qualitative and 
quantitative confirmation of results for all of the parameters listed 
above, using the extract produced by this method.
    1.3  The method detection limit (MDL, defined in Section 14.1)1 
for each parameter is listed in Table 1. The MDL for a specific 
wastewater may differ from those listed, depending upon the nature of 
interferences in the sample matrix.
    1.4  The sample extraction and concentration steps in this method 
are essentially the same as in Methods 606, 608, 609, and 611. Thus, a 
single sample may be extracted to measure the parameters included in the 
scope of each of these methods. When cleanup is required, the 
concentration levels must be high enough to permit selecting aliquots, 
as necessary, to apply appropriate cleanup procedures. The analyst is 
allowed the latitude, under Section 12, to select chromatographic 
conditions appropriate for the simultaneous measurement of combinations 
of these parameters.
    1.5  Any modification of this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5.
    1.6  This method is restricted to use by or under the supervision of 
analysts experienced in the use of a gas chromatograph and in the 
interpretation of gas chromatograms. Each analyst must demonstrate the 
ability to generate acceptable results with this method using the 
procedure described in Section 8.2.

                          2. Summary of Method

    2.1  A measured volume of sample, approximately 1-L, is extracted 
with methylene chloride using a separatory funnel. The methylene 
chloride extract is dried and exchanged to hexane during concentration 
to a volume of 10 mL or less. The extract is separated by gas 
chromatography and the parameters are then measured with an electron 
capture detector.2
    2.2  The method provides a Florisil column cleanup procedure to aid 
in the elimination of interferences that may be encountered.

                            3. Interferences

    3.1  Method interferences may be caused by contaminants in solvents, 
reagents, glassware, and other sample processing hardware that lead to 
discrete artifacts and/or elevated baselines in gas chromatograms. All 
of these materials must be routinely demonstrated to be free from 
interferences under the conditions of the analysis by running laboratory 
reagent blanks as described in Section 8.1.3.
    3.1.1  Glassware must be scrupulously cleaned.3 Clean all 
glassware as soon as possible after use by rinsing with the last solvent 
used in it. Solvent rinsing should be followed by detergent washing with 
hot water, and rinses with tap water and distilled water. The glassware 
should then be drained dry, and heated in a muffle furnace at 400  deg.C 
for 15 to 30 min. Some thermally stable materials, such as PCBs, may not 
be eliminated by this treatment. Solvent rinses with acetone and 
pesticide quality hexane may be substituted for the muffle furnace 
heating. Thorough rinsing with such solvents usually eliminates PCB 
interference. Volumetric ware should not be heated in a muffle furnace. 
After drying and cooling, glassware should be sealed and stored in a 
clean environment to prevent any accumulation of dust or other 
contaminants. Store inverted or capped with aluminum foil.
    3.1.2  The use of high purity reagents and solvents helps to 
minimize interference problems. Purification of solvents by distillation 
in all-glass systems may be required.
    3.2  Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary 
considerably from source to source, depending upon the nature and 
diversity of the industrial complex or municipality being sampled. The 
cleanup procedure in Section 11 can be used to overcome many of these 
interferences, but unique samples may require additional cleanup 
approaches to achieve the MDL listed in Table 1.

[[Page 170]]

                                4. Safety

    4.1  The toxicity or carcinogenicity of each reagent used in this 
method has not been precisely defined; however, each chemical compound 
should be treated as a potential health hazard. From this viewpoint, 
exposure to these chemicals must be reduced to the lowest possible level 
by whatever means available. The laboratory is responsible for 
maintaining a current awareness file of OSHA regulations regarding the 
safe handling of the chemicals specified in this method. A reference 
file of material data handling sheets should also be made available to 
all personnel involved in the chemical analysis. Additional references 
to laboratory safety are available and have been identified 4-6 for 
the information of the analyst.

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete or composite sampling.
    5.1.1  Grab sample bottle--1cL or 1-qt, amber glass, fitted with a 
screw cap lined with Teflon. Foil may be substituted for Teflon if the 
sample is not corrosive. If amber bottles are not available, protect 
samples from light. The bottle and cap liner must be washed, rinsed with 
acetone or methylene chloride, and dried before use to minimize 
contamination.
    5.1.2  Automatic sampler (optional)--The sampler must incorporate 
glass sample containers for the collection of a minimum of 250 mL of 
sample. Sample containers must be kept refrigerated at 4  deg.C and 
protected from light during compositing. If the sampler uses a 
peristaltic pump, a minimum length of compressible silicone rubber 
tubing may be used. Before use, however, the compressible tubing should 
be thoroughly rinsed with methanol, followed by repeated rinsings with 
distilled water to minimize the potential for contamination of the 
sample. An integrating flow meter is required to collect flow 
proportional composites.
    5.2  Glassware (All specifications are suggested. Catalog numbers 
are included for illustration only.):
    5.2.1  Separatory funnel--2-L, with Teflon stopcock.
    5.2.2  Drying column--Chromatographic column, approximately 400 mm 
long x 19 mm ID, with coarse frit filter disc.
    5.2.3  Chromatographic column--300 long x 10 mm ID, with Teflon 
stopcock and coarse frit filter disc at bottom.
    5.2.4  Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes 
K-570050-1025 or equivalent). Calibration must be checked at the volumes 
employed in the test. Ground glass stopper is used to prevent 
evaporation of extracts.
    5.2.5  Evaporative flask, Kuderna-Danish--500-mL (Kontes K-570001-
0500 or equivalent). Attach to concentrator tube with springs.
    5.2.6  Snyder column, Kuderna-Danish--Three-ball macro (Kontes K-
503000-0121 or equivalent).
    5.2.7  Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
    5.3  Boiling chips--Approximately 10/40 mesh. Heat to 400  deg.C for 
30 min or Soxhlet extract with methylene chloride.
    5.4  Water bath--Heated, with concentric ring cover, capable of 
temperature control ( 2  deg.C). The bath should be used in 
a hood.
    5.5  Balance--Analytical, capable of accurately weighing 0.0001 g.
    5.6  Gas chromatograph--An analytical system complete with gas 
chromatograph suitable for on-column injection and all required 
accessories including syringes, analytical columns, gases, detector, and 
strip-chart recorder. A data system is recommended for measuring peak 
areas.
    5.6.1  Column 1--1.8 m long x 2 mm ID glass, packed with 1% SP-1000 
on Supelcoport (100/120 mesh) or equivalent. Guidelines for the use of 
alternate column packings are provide in Section 12.1.
    5.6.2  Column 2--1.8 m long  x  2 mm ID glass, packed with 1.5% OV-
1/2.4% OV-225 on Supelcoport (80/100 mesh) or equivalent. This column 
was used to develop the method performance statements in Section 14.
    5.6.3  Detector-- Electron capture detector. This detector has 
proven effective in the analysis of wastewaters for the parameters 
listed in the scope (Section 1.1), and was used to develop the method 
performance statements in Section 14. Guidelines for the use of 
alternate detectors are provided in Section 12.1.

                               6. Reagents

    6.1  Reagent water-- Reagent water is defined as a water in which an 
interferent is not observed at the MDL of the parameters of interest.
    6.2  Acetone, hexane, isooctane, methanol, methylene chloride, 
petroleum ether (boiling range 30 to 60  deg.C)--Pesticide quality or 
equivalent.
    6.3  Sodium sulfate--(ACS) Granular, anhydrous. Purify heating at 
400  deg.C for 4 h in a shallow tray.
    6.4  Florisil--PR grade (60/100 mesh). Purchase activated at 1250 
deg.F and store in the dark in glass containers with ground glass 
stoppers or foil-lined screw caps. Before use, activate each batch at 
least 16 h at 130  deg. C in a foil-covered glass container and allow to 
cool.
    6.5  Stock standard solution (1.00 g/L)--Stock 
standard solutions can be prepared from pure standard materials or 
purchased as certified solutions.
    6.5.1  Prepare stock standard solutions by accurately weighing about 
0.0100 g of pure material. Dissolve the material in isooctane and dilute 
to volume in a 120-mL volumetric

[[Page 171]]

flask. Larger volumes can be used at the convenience of the analyst. 
When compound purity is assayed to be 96% or greater, the weight can be 
used without correction to calculate the concentration of the stock 
standard. Commercially prepared stock standards can be used at any 
concentration if they are certified by the manufacturer or by an 
independent source.
    6.5.2  Transfer the stock standard solutions into Teflon-sealed 
screw-cap bottles. Store at 4  deg.C and protect from light. Stock 
standard solutions should be checked frequently for signs of degradation 
or evaporation, especially just prior to preparing calibration standards 
from them.
    6.5.3  Stock standard solutions must be replaced after six months, 
or sooner if comparision with check standards indicates a problem.
    6.6  Quality control check sample concentrate--See Section 8.2.1.

                             7. Calibration

    7.1  Establish gas chromatographic operating conditions equivalent 
to those given in Table 1. The gas chromatographic system can be 
calibrated using the external standard technique (Section 7.2) or the 
internal standard technique (Section 7.3).
    7.2  External standard calibration procedure:
    7.2.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask and diluting to volume 
with isooctane. One of the external standards should be at a 
concentration near, but above, the MDL (Table 1) and the other 
concentrations should correspond to the expected range of concentrations 
found in real samples or should define the working range of the 
detector.
    7.2.2  Using injections of 2 to 5 L, analyze each 
calibration standard according to Section 12 and tabulate peak height or 
area responses against the mass injected. The results can be used to 
prepare a calibration curve for each compound. Alternatively, if the 
ratio of response to amount injected (calibration factor) is a constant 
over the working range (<10% relative standard deviation, RSD), 
linearity through the origin can be assumed and the average ratio or 
calibration factor can be used in place of a calibration curve.
    7.3  Internal standard calibration procedure--To use this approach, 
the analyst must select one or more internal standards that are similar 
in analytical behavior to the compounds of interest. The analyst must 
further demonstrate that the measurement of the internal standard is not 
affected by method or matrix interferences. Because of these 
limitations, no internal standard can be suggested that is applicable to 
all samples.
    7.3.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding volumes of 
one or more stock standards to a volumetric flask. To each calibration 
standard, add a known constant amount of one or more internal standards, 
and dilute to volume with isooctane. One of the standards should be at a 
concentration near, but above, the MDL and the other concentrations 
should correspond to the expected range of concentrations found in real 
samples or should define the working range of the detector.
    7.3.2  Using injections of 2 to 5 L, analyze each 
calibration standard according to Section 12 and tabulate peak height or 
area responses against concentration for each compound and internal 
standard. Calculate response factors (RF) for each compound using 
Equation 1.

                                                                        
                                            (As)(Cis)                   
                                   RF=   --------------                 
                                            (Ais)(Cs)                   
                                                                        

                                                              Equation 1
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Cis=Concentration of the internal standard (g/L).
    Cs=Concentration of the parameter to be measured (g/
L).

If the RF value over the working range is a constant (<10% RSD), the RF 
can be assumed to be invariant and the average RF can be used for 
calculations. Alternatively, the results can be used to plot a 
calibration curve of response ratios, As/Ais, vs. RF.
    7.4  The working calibration curve, calibration factor, or RF must 
be verified on each working day by the measurement of one or more 
calibration standards. If the response for any parameter varies from the 
predicted response by more than 15%, a new calibration curve 
must be prepared for that compound.
    7.5  Before using any cleanup procedure, the analyst must process a 
series of calibration standards through the procedure to validate 
elution patterns and the absence of interferences from the reagents.

                           8. Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality control program. The minimum requirements of this program 
consist of an initial demonstration of laboratory capability and an 
ongoing analysis of spiked samples to evaluate and document data 
quality. The laboratory must maintain records to document the quality of

[[Page 172]]

data that is generated. Ongoing data quality checks are compared with 
established performance criteria to determine if the results of analyses 
meet the performance characteristics of the method. When the results of 
sample spikes indicate atypical method performance, a quality control 
check standard must be analyzed to confirm that the measurements were 
performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occurring in 
chromatography, the analyst is permitted certain options (detailed in 
Sections 10.4, 11.1, and 12.1) to improve the separations or lower the 
cost of measurements. Each time such modification is made to the method, 
the analyst is required to repeat the procedure in Section 8.2.
    8.1.3  Before processing any samples, the analyst must analyze a 
reagent water blank to demonstrate that interferences from the 
analytical system and glassware are under control. Each time a set of 
samples is extracted or reagents are changed, a reagent water blank must 
be processed as a safeguard against laboratory contamination.
    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 10% of all samples to monitor and evaluate laboratory data 
quality. This procedure is described in Section 8.3.
    8.1.5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 10% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.5.
    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality control (QC) check sample concentrate is required 
containing each parameter of interest at the following concentrations in 
acetone: Hexachloro-substituted parameters, 10 g/mL; any other 
chlorinated hydrocarbon, 100 g/mL. The QC check sample 
concentrate must be obtained from the U.S. Environmental Protection 
Agency, Environmental Monitoring and Support Laboratory in Cincinnati, 
Ohio, if available. If not available from that source, the QC check 
sample concentrate must be obtained from another external source. If not 
available from either source above, the QC check sample concentrate must 
be prepared by the laboratory using stock standards prepared 
independently from those used for calibration.
    8.2.2  Using a pipet, prepare QC check samples at the test 
concentrations shown in Table 2 by adding 1.00 mL of QC check sample 
concentrate to each of four 1-L aliquots of reagent water.
    8.2.3  Analyze the well-mixed QC check samples according to the 
method beginning in Section 10.
    8.2.4  Calculate the average recovery (X) in g/L, and the 
standard deviation of the recovery (s) in g/L, for each 
parameter using the four results.
    8.2.5  For each parameter compare s and X with the corresponding 
acceptance criteria for precision and accuracy, respectively, found in 
Table 2. If s and X for all parameters of interest meet the acceptance 
criteria, the system performance is acceptable and analysis of actual 
samples can begin. If any individual s exceeds the precision limit or 
any individual X falls outside the range for accuracy, the system 
performance is unacceptable for that parameter.

    Note: The large number of parameters in Table 2 presents a 
substantial probability that one or more will fail at least one of the 
acceptance criteria when all parameters are analyzed.

    8.2.6  When one or more of the parameters tested fail at least one 
of the acceptance criteria, the analyst must proceed according to 
Section 8.2.6.1 or 8.2.6.2.
    8.2.6.1  Locate and correct the source of the problem and repeat the 
test for all parameters of interest beginning with Section 8.2.2.
    8.2.6.2  Beginning with Section 8.2.2, repeat the test only for 
those parameters that failed to meet criteria. Repeated failure, 
however, will confirm a general problem with the measurement system. If 
this occurs, locate and correct the source of the problem and repeat the 
test for all compounds of interest beginning with Section 8.2.2.
    8.3  The laboratory must, on an ongoing basis, spike at least 10% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing one to ten samples per month, at least one 
spike sample per month is required.
    8.3.1  The concentration of the spike in the sample should be 
determined as follows:
    8.3.1.1  If, as in compliance monitoring, the concentration of a 
specific parameter in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of a specific parameter in the sample 
is not being

[[Page 173]]

checked against a limit specific to that parameter, the spike should be 
at the test concentration in Section 8.2.2 or 1 to 5 times higher than 
the background concentration determined in Section 8.3.2, whichever 
concentration would be larger.
    8.3.1.3  If it is impractical to determine background levels before 
spiking (e.g., maximum holding times will be exceeded), the spike 
concentration should be (1) the regulatory concentration limit, if any; 
or, if none by (2) the larger of either 5 times higher than the expected 
background concentration or the test concentration in Section 8.2.2.
    8.3.2 Analyze one sample aliquot to determine the background 
concentration (B) of each parameter. In necessary, prepare a new QC 
check sample concentrate (Section 8.2.1) appropriate for the background 
concentrations in the sample. Spike a second sample aliquot with 1.0 mL 
of the QC check sample concentrate and analyze it to determine the 
concentration after spiking (A) of each parameter. Calculate each 
percent recovery (P) as 100 (A-B)%/T, where T is the known true value of 
the spike.
    8.3.3 Compare the percent recovery (P) for each parameter with the 
corresponding QC acceptance criteria found in Table 2. These acceptance 
criteria were calculated to include an allowance for error in 
measurement of both the background and spike concentrations, assuming a 
spike to background ratio of 5:1. This error will be accounted for to 
the extent that the analyst's spike to background ratio approaches 
5:1.7 If spiking was performed at a concentration lower than the 
test concentration in Section 8.2.2, the analyst must use either the QC 
acceptance criteria in Table 2, or optional QC acceptance criteria 
calculated for the specific spike concentration. To calculate optional 
acceptance criteria for the recovery of a parameter: (1) Calculate 
accuracy (X') using the equation in Table 3, substituting the spike 
concentration (T) for C; (2) calculate overall precision (S') using the 
equation in Table 3, substituting X' for X; (3) calculate the range for 
recovery at the spike concentration as (100 X'/T)  2.44 (100 
S'/T)%.7
    8.3.4 If any individual P falls outside the designated range for 
recovery, that parameter has failed the acceptance criteria. A check 
standard containing each parameter that failed the criteria must be 
analyzed as described in Section 8.4.
    8.4. If any parameter fails the acceptance criteria for recovery in 
Section 8.3, a QC check standard containing each parameter that failed 
must be prepared and analyzed.

    Note: The frequency for the required analysis of a QC check standard 
will depend upon the number of parameters being simultaneously tested, 
the complexity of the sample matrix, and the performance of the 
laboratory.

    8.4.1 Prepare the QC check standard by adding 1.0 mL of QC check 
sample concentrate (Sections 8.2.1 or 8.3.2) to 1 L of reagent water. 
The QC check standard needs only to contain the parameters that failed 
criteria in the test in Section 8.3.
    8.4.2  Analyze the QC check standard to determine the concentration 
measured (A) of each parameter. Calculate each percent recovery 
(Ps) as 100 (A/T)%, where T is the true value of the standard 
concentration.
    8.4.3  Compare the percent recovery (Ps) for each parameter 
with the corresponding QC acceptance criteria found in Table 2. Only 
parameters that failed the test in Section 8.3 need to be compared with 
these criteria. If the recovery of any such parameter falls outside the 
designated range, the laboratory performance for that parameter is 
judged to be out of control, and the problem must be immediately 
identified and corrected. The analytical result for that parameter in 
the unspiked sample is suspect and may not be reported for regulatory 
compliance purposes.
    8.5  As part of the QC program for the laboratory, method accuracy 
for wastewater samples must be assessed and records must be maintained. 
After the analysis of five spiked wastewater samples as in Section 8.3, 
calculate the average percent recovery (P) and the standard deviation of 
the percent recovery (sp). Express the accuracy assessment as a 
percent recovery interval from P-2sp to P+2sp. If P=90% and 
sp=10%, for example, the accuracy interval is expressed as 70-110%. 
Update the accuracy assessment for each parameter on a regular basis 
(e.g. after each five to ten new accuracy measurements).
    8.6  It is recommended that the laboratory adopt additional quality 
assurance practices for use with this method. The specific practices 
that are most productive depend upon the needs of the laboratory and the 
nature of the samples. Field duplicates may be analyzed to assess the 
precision of the environmental measurements. When doubt exists over the 
identification of a peak on the chromatogram, confirmatory techniques 
such as gas chromatography with a dissimilar column, specific element 
detector, or mass spectrometer must be used. Whenever possible, the 
laboratory should analyze standard reference materials and participate 
in relevent performance evaluation studies.

            9. Sample Collection, Preservation, and Handling

    9.1  Grab samples must be collected in glass containers. 
Conventional sampling practices 8 should be followed, except that 
the bottle must not be prerinsed with sample before collection. 
Composite samples should be collected in refrigerated glass containers 
in accordance with the requirements of the program. Automatic sampling 
equipment must be as free as possible of Tygon tubing

[[Page 174]]

and other potential sources of contamination.
    9.2  All samples must be iced or refrigerated at 4  deg.C from the 
time of collection until extraction.
    9.3  All samples must be extracted within 7 days of collection and 
completely analyzed within 40 days of extraction.2

                          10. Sample Extraction

    10.1  Mark the water meniscus on the side of the sample bottle for 
later determination of sample volume. Pour the entire sample into a 2-L 
separatory funnel.
    10.2  Add 60 mL of methylele chloride to the sample bottle, seal, 
and shake 30 s to rinse the inner surface. Transfer the solvent to the 
separatory funnel and extract the sample by shaking the funnel for 2 min 
with periodic venting to release excess pressure. Allow the organic 
layer to separate from the water phase for a minimum of 10 min. If the 
emulsion interface between layers is more than one-third the volume of 
the solvent layer, the analyst must employ mechanical techniques to 
complete the phase separation. The optimum technique depends upon the 
sample, but may include stirring, filtration of the emulsion through 
glass wool, centrifugation, or other physical methods. Collect the 
methylene chloride extract in a 250-mL Erlenmeyer flask.
    10.3  Add a second 60-mL volume of methylene chloride to the sample 
bottle and repeat the extraction procedure a second time, combining the 
extracts in the Erlenmeyer flask. Perform a third extraction in the same 
manner.
    10.4  Assemble a Kuderna-Danish (K-D) concentrator by attaching a 
10-mL concentrator tube to a 500-mL evaporative flask. Other 
concentration devices or techniques may be used in place of the K-D 
concentrator if the requirements of Section 8.2 are met.
    10.5  Pour the combined extract through a solvent-rinsed drying 
column containing about 10 cm of anhydrous sodium sulfate, and collect 
the extract in the K-D concentrator. Rinse the Erlenmeyer flask and 
column with 20 to 30 mL of methylene chloride to complete the 
quantitative transfer.
    10.6  Add one or two clean boiling chips to the evaporative flask 
and attach a three-ball Snyder column. Prewet the Snyder column by 
adding about 1 mL of methylene chloride to the top. Place the K-D 
apparatus on a hot water bath (60 to 65  deg.C) so that the concentrator 
tube is partially immersed in the hot water, and the entire lower 
rounded surface of the flask is bathed with hot vapor. Adjust the 
vertical position of the apparatus and the water temperature as required 
to complete the concentration in 15 to 20 min. At the proper rate of 
distillation the balls of the column will actively chatter but the 
chambers will not flood with condensed solvent. When the apparent volume 
of liquid reaches 1 to 2 mL, remove the K-D apparatus and allow it to 
drain and cool for at least 10 min.

    Note: The dichloribenzenes have a sufficiently high volatility that 
significant losses may occur in concentration steps if care is not 
exercised. It is important to maintain a constant gentle evaporation 
rate and not to allow the liquid volume to fall below 1 to 2 mL before 
removing the K-D apparatus from the hot water bath.

    10.7  Momentarily remove the Snyder column, add 50 mL of hexane and 
a new boiling chip, and reattach the Snyder column. Raise the tempeature 
of the water bath to 85 to 90  deg.C. Concentrate the extract as in 
Section 10.6, except use hexane to prewet the column. The elapsed time 
of concentration should be 5 to 10 min.
    10.8  Romove the Snyder column and rinse the flask and its lower 
joint into the concentrator tube with 1 to 2 mL of hexane. A 5-mL 
syringe is recommended for this operation. Stopper the concentrator tube 
and store refrigerated if further processing will not be performed 
immediately. If the extract will be stored longer than two days, it 
should be transferred to a Teflon-sealed screw-cap vial. If the sample 
extract requires no further cleanup, proceed with gas chromatographic 
analysis (Section 12). If the sample requires further cleanup, proceed 
to Section 11.
    10.9  Determine the original sample volume by refilling the sample 
bottle to the mark and transferring the liquid to a 1000-mL graduated 
cylinder. Record the sample volume to the nearest 5 mL.

                       11. Cleanup and Separation

    11.1  Cleanup procedures may not be necessary for a relatively clean 
sample matrix. If particular circumstances demand the use of a cleanup 
procedure, the analyst may use the procedure below or any other 
appropriate procedure. However, the analyst first must demonstrate that 
the requirements of Section 8.2 can be met using the method as revised 
to incorporate the cleanup procedure.
    11.2  Florisil column cleanup for chlorinated hydrocarbons:
    11.2.1  Adjust the sample extract to 10 mL with hexane.
    11.2.2  Place 12 g of Florisil into a chromatographic column. Tap 
the column to settle the Florisil and add 1 to 2 cm of anhydrous sodium 
sulfate to the top.
    11.2.3  Preelute the column with 100 mL of petroleum ether. Discard 
the eluate and just prior to exposure of the sodium sulfate layer to the 
air, quantitatively transfer the sample extract onto the column by 
decantation and subsequent petroleum ether washings. Discard the eluate. 
Just prior to exposure of the sodium sulfate layer to the air, begin

[[Page 175]]

eluting the column with 200 mL of petroleum ether and collect the eluate 
in a 500-mL K-D flask equipped with a 10-mL concentrator tube. This 
fraction should contain all of the chlorinated hydrocarbons.
    11.2.4  Concentrate the fraction as in Section 10.6, except use 
hexane to prewet the column. When the apparatus is cool, remove the 
Snyder column and rinse the flask and its lower joint into the 
concentrator tube with hexane. Analyze by gas chromatography (Section 
12).

                         12. Gas Chromatography

    12.1  Table 1 summarizes the recommended operating conditions for 
the gas chromatograph. Included in this table are retention times and 
MDL that can be achieved under these conditions. Examples of the 
separations achieved by Columl 2 are shown in Figures 1 and 2. Other 
packed or capillary (open-tubular) columns, chromatographic conditions, 
or detectors may be used if the requirements of Section 8.2 are met.
    12.2  Calibrate the system daily as described in Section 7.
    12.3  If the internal standard calibration procedure is being used, 
the internal standard must be added to the sample extract and mixed 
throughly immediately before injection into the gas chromatograph.
    12.4  Inject 2 to 5 L of the sample extract or standard 
into the gas chromatograph using the solvent-flush techlique.9 
Smaller (1.0 L) volumes may be injected if automatic devices 
are employed. Record the volume injected to the nearest 0.05 L, 
the total extract volume, and the resulting peak size in area or peak 
height units.
    12.5  Identify the parameters in the sample by comparing the 
retention times of the peaks in the sample chromatogram with those of 
the peaks in standard chromatograms. The width of the retention time 
window used to make identifications should be based upon measurements of 
actual retention time variations of standards over the course of a day. 
Three times the standard deviation of a retention time for a compound 
can be used to calculate a suggested window size; however, the 
experience of the analyst should weigh heavily in the interpretation of 
chromatograms.
    12.6  If the response for a peak exceeds the working range of the 
system, dilute the extract and reanalyze.
    12.7  If the measurement of the peak response is prevented by the 
presence of interferences, further cleanup is required.

                            13. Calculations

    13.1  Determine the concentration of individual compounds in the 
sample.
    13.1.1  If the external standard calibration procedure is used, 
calculate the amount of material injected from the peak response using 
the calibration curve or calibration factor determined in Section 7.2.2. 
The concentration in the sample can be calculated from Equation 2.

                                                                                                                
                                                                           (A)(Vt)                              
                                        Concentration (g/  = -----------------                         
                                                    L)                     (Vi)(Vs)                             
                                                                                                                

                                                              Equation 2
where:
    A=Amount of material injected (ng).
    Vi=Volume of extract injected (L).
    Vt=Volume of total extract (L).
    Vs=Volume of water extracted (mL).

    13.1.2  If the internal standard calibration procedure is used, 
calculate the concentration in the sample using the response factor (RF) 
determined in Section 7.3.2 and Equation 3.

                                                                                                                
                                                                           (As)(Is)                             
                                        Concentration (g/  = -----------------                         
                                                    L)                  (Ais)(RF)(Vo)                           
                                                                                                                

                                                              Equation 3
where:
    As=Response for the parameter to be measured.
    Ais=Response for the internal standard.
    Is=Amount of internal standard added to each extract 
(g).
    Vo=Volume of water extracted (L).

    13.2  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

                         14. Method Performance

    14.1  The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the value is above zero.1 The MDL concentrations 
listed in Table 1 were obtained using reagent water.10 Similar 
results were achieved using representative wastewaters. The MDL actually 
achieved in a given analysis will vary depending on instrument 
sensitivity and matrix effects.
    14.2  This method has been tested for linearity of spike recovery 
from reagent water and has been demonstrated to be applicable over the 
concentration range from 4 x MDL to 1000 x MDL.10
    14.3  This method was tested by 20 laboratories using reagent water, 
drinking water, surface water, and three industrial wastewaters spiked 
at six concentrations over the range 1.0 to 356 g/L.11 
Single operator precision, overall precision, and method accuracy were 
found to be directly related to the concentration of the parameter and 
essentially independent of the sample matrix. Linear equations to 
describe these relationships are presented in Table 3.

[[Page 176]]

                               References

    1. 40 CFR part 136, appendix B.
    2. ``Determination of Chlorinated Hydrocarbons In Industrial and 
Municipal Wastewaters, ``EPA 6090/4-84-ABC, National Technical 
Information Service, PBXYZ, Springfield, Virginia, 22161 November 1984.
    3. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard 
Practices for Preparation of Sample Containers and for Preservation of 
Organic Constituents,'' American Society for Testing and Materials, 
Philadelphia.
    4. ``Carcinogens--Working With Carcinogens,'' Department of Health, 
Education, and Welfare, Public Health Service, Center for Disease 
Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    5. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR 
part 1910), Occupational Safety and Health Administration, OSHA 2206 
(Revised, January 1976).
    6. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent 
Recovery Data,''American Laboratory, 15, 58-63 (1983). (The value 2.44 
used in the equation in Section 8.3.3 is two times the value 1.22 
derived in this report.)
    8. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard 
Practices for Sampling Water,'' American Society for Testing and 
Materials, Philadelphia.
    9. Burke, J.A. ``Gas Chromatography for Pesticide Residue Analysis; 
Some Practical Aspects,'' Journal of the Association of Official 
Analytical Chemists, 48, 1037 (1965).
    10. ``Development of Detection Limits, EPA Method 612, Chlorinated 
Hydrocarbons,'' Special letter report for EPA Contract 68-03-2625, U.S. 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory, Cincinnati, Ohio 45268.
    11. ``EPA Method Study Method 612--Chlorinated Hydrocarbons,'' EPA 
600/4-84-039, National Technical Information Service, PB84-187772, 
Springfield, Virginia 22161, May 1984.
    12. ``Method Performance for Hexachlorocyclopentadiene by Method 
612,'' Memorandum from R. Slater, U.S. Environmental Protection Agency, 
Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, 
December 7, 1983.

     Table 1--Chromatographic Conditions and Method Detection Limits    
------------------------------------------------------------------------
                                    Retention time (min)       Method   
                                 --------------------------   detection 
            Parameter                                           limit   
                                    Column 1     Column 2   (g/
                                                                 L)     
------------------------------------------------------------------------
1,3-Dichlorobenzene.............          4.5          6.8          1.19
Hexachloroethane................          4.9          8.3          0.03
1,4-Dichlorobenzene.............          5.2          7.6          1.34
1,2-Dichlorobenzene.............          6.6          9.3          1.14
Hexachlorobutadiene.............          7.7         20.0          0.34
1,2,4-Trichlorobenzene..........         15.5         22.3          0.05
Hexachlorocyclopentadiene.......           nd       c 16.5          0.40
2-Chloronaphthalene.............        a 2.7        b 3.6          0.94
Hexachlorobenzene...............        a 5.6       b 10.1         0.05 
------------------------------------------------------------------------
Column 1 conditions: Supelcoport (100/120 mesh) coated with 1% SP-1000  
  packed in a 1.8 m x 2 mm ID glass column with 5% methane/95% argon    
  carrier gas at 25 mL/min. flow rate. Column temperature held          
  isothermal at 65 C, except where otherwise indicated.                 
Column 2 conditions: Supelcoport (80/100 mesh) coated with 1.5% OV-1/   
  2.4% OV-225 packed in a 1.8 m x 2 mm ID glass column with 5% methane/ 
  95% argon carrier gas at 25 mL/min. flow rate. Column temperature held
  isothermal at 75 C, except where otherwise indicated.                 
                                                                        
nd=Not determined.                                                      
a 150 C column temperature.                                             
b 165 C column temperature.                                             
c 100 C column temperature.                                             


                                   Table 2--QC Acceptance Criteria--Method 612                                  
----------------------------------------------------------------------------------------------------------------
                                                                                          Range for X           
                                                              Test conc.    Limit for s  (g/  Range for
                         Parameter                           (g/  (g/       L)         P, Ps  
                                                                  L)            L)                     (percent)
----------------------------------------------------------------------------------------------------------------
2-Chloronaphthalene........................................          100          37.3     29.5-126.9      9-148
1,2-Dichlorobenzene........................................          100          28.3     23.5-145.1      9-160
1,3-Dichlorobenzene........................................          100          26.4      7.2-138.6      D-150
1,4-Dichlorobenzene........................................          100          20.8     22.7-126.9     13-137
Hexachlorobenzene..........................................           10           2.4       2.6-14.8     15-159
Hexachlorobutadiene........................................           10           2.2         D-12.7      D-139
Hexachlorocyclopentadiene..................................           10           2.5         D-10.4      D-111
Hexachloroethane...........................................           10           3.3       2.4-12.3      8-139

[[Page 177]]

                                                                                                                
1,2,4-Trichlorobenzene.....................................          100          31.6     20.2-133.7      5-149
----------------------------------------------------------------------------------------------------------------
s=Standard deviation of four recovery measurements, in g/L (Section 8.2.4).                            
X=Average recovery for four recovery measurements, in g/L (Section 8.2.4).                             
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).                                                 
D=Detected; result must be greater than zero.                                                                   
                                                                                                                
Note: These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits
  for recovery have been broadened to assure applicability of the limits to concentrations below those used to  
  develop Table 3.                                                                                              


                Table 3--Method Accuracy and Precision as Functions of Concentration--Method 612                
----------------------------------------------------------------------------------------------------------------
                                                                      Single analyst                            
               Parameter                Acccuracy, as recovery,   precision, sr (g/L)              m>g/L)              (g/L)    
----------------------------------------------------------------------------------------------------------------
2-Chloronaphthalene...................  0.75C+3.21               0.28X-1.17               0.38X-1.39            
1,2-Dichlorobenzene...................  0.85C-0.70               0.22X-2.95               0.41X-3.92            
1,3-Dichlorobenzene...................  0.72C+0.87               0.21X-1.03               0.49X-3.98            
1,4-Dichlorobenzene...................  0.72C+2.80               0.16X-0.48               0.35X-0.57            
Hexachlorobenzene.....................  0.87C-0.02               0.14X+0.07               0.36X-0.19            
Hexachlorobutadiene...................  0.61C+0.03               0.18X+0.08               0.53X-0.12            
Hexachlorocyclopentadiene a...........  0.47C                    0.24X                    0.50X                 
Hexachloroethane......................  0.74C-0.02               0.23X+0.07               0.36X-0.00            
1,2,4-Trichlorobenzene................  0.76C+0.98               0.23X-0.44               0.40X-1.37            
----------------------------------------------------------------------------------------------------------------
X=Expected recovery for one or more measurements of a sample containing a concentration of C, in g/L.  
sr=Expected single analyst standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
S=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
C=True value for the concentration, in g/L.                                                            
X=Average recovery found for measurements of samples containing a concentration of C, in g/L.          
                                                                                                                
a Estimates based upon the performance in a single laboratory.\12\                                              


[[Page 178]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.036


[[Page 179]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.037


[[Page 180]]

             Method 613--2,3,7,8-Tetrachlorodibenzo-p-Dioxin

                        1. Scope and Application

    1.1  This method covers the determination of 2,3,7,8-
tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). The following parameter may 
be determined by this method:

------------------------------------------------------------------------
                                                    STORET              
                    Parameter                        No.       GAS No.  
------------------------------------------------------------------------
2,3,7,8-TCDD.....................................    34675     1746-01-6
------------------------------------------------------------------------

    1.2  This is a gas chromatographic/mass spectrometer (GC/MS) method 
applicable to the determination of 2,3,7,8-TCDD in municipal and 
industrial discharges as provided under 40 CFR 136.1. Method 625 may be 
used to screen samples for 2,3,7,8-TCDD. When the screening test is 
positive, the final qualitative confirmation and quantification must be 
made using Method 613.
    1.3  The method detection limit (MDL, defined in Section 14.1) 
1 for 2,3,7,8-TCDD is listed in Table 1. The MDL for a specific 
wastewater may be different from that listed, depending upon the nature 
of interferences in the sample matrix.
    1.4  Because of the extreme toxicity of this compound, the analyst 
must prevent exposure to himself, of to others, by materials knows or 
believed to contain 2,3,7,8-TCDD. Section 4 of this method contains 
guidelines and protocols that serve as minimum safe-handling standards 
in a limited-access laboratory.
    1.5  Any modification of this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5.
    1.6  This method is restricted to use by or under the supervision of 
analysts experienced in the use of a gas chromatograph/mass spectrometer 
and in the interpretation of mass spectra. Each analyst must demonstrate 
the ability to generate acceptable results with this method using the 
procedure described in Section 8.2.

                          2. Summary of Method

    2.1  A measured volume of sample, approximately 1-L, is spiked with 
an internal standard of labeled 2,3,7,8-TCDD and extracted with 
methylene chloride using a separatory funnel. The methylene chloride 
extract is exchanged to hexane during concentration to a volume of 1.0 
mL or less. The extract is then analyzed by capillary column GC/MS to 
separate and measure 2,3,7,8-TCDD.2,3
    2.2  The method provides selected column chromatographic cleanup 
proceudres to aid in the elimination of interferences that may be 
encountered.

                            3. Interferences

    3.1  Method interferences may be caused by contaminants in solvents, 
reagents, glassware, and other sample processing hardware that lead to 
discrete artifacts and/or elevated backgrounds at the masses (m/z) 
monitored. All of these materials must be routinely demonstrated to be 
free from interferences under the conditions of the analysis by running 
laboratory reagent blanks as described in Section 8.1.3.
    3.1.1  Glassware must be scrupulously cleaned.4 Clean all 
glassware as soon as possible after use by rinsing with the last solvent 
used in it. Solvent rinsing should be followed by detergent washing with 
hot water, and rinses with tap water and distilled water. The glassware 
should then be drained dry, and heated in a muffle furnace at 400  deg.C 
for 15 to 30 min. Some thermally stable materials, such as PCBs, may not 
be eliminated by the treatment. Solvent rinses with acetone and 
pesticide quality hexane may be substituted for the muffle furnace 
heating. Thorough rinsing with such solvents usually eliminates PCB 
interference. Volumetric ware should not be heated in a muffle furnace. 
After drying and cooling, glassware should be sealed and stored in a 
clean environment to prevent any accumulation of dust or other 
contaminants. Store inverted or capped with aluminum foil.
    3.1.2  The use of high purity reagents and solvents helps to 
mininmize interference problems. Purification of solvents by 
distillation in all-glass systems may be required.
    3.2  Matrix interferences may be caused by contaminants that are 
coextracted from the sample. The extent of matrix interferences will 
vary considerably from source to source, depending upon the nature and 
diversity of the industrial complex or municipality being sampled. 
2,3,7,8-TCDD is often associated with other interfering chlorinated 
compounds which are at concentrations several magnitudes higher than 
that of 2,3,7,8-TCDD. The cleanup producers in Section 11 can be used to 
overcome many of these interferences, but unique samples may require 
additional cleanup approaches 1,5-7 to eliminate false positives 
and achieve the MDL listed in Table 1.
    3.3  The primary column, SP-2330 or equivalent, resolves 2,3,7,8-
TCDD from the other 21 TCDD insomers. Positive results using any other 
gas chromatographic column must be confirmed using the primary column.

                                4. Safety

    4.1  The toxicity or carcinogenicity of each reagent used in this 
method has not been precisely defined; however, each chemical compound 
should be treated as a potential health hazard. From this viewpoint, 
exposure to these chemicals must be reduced to

[[Page 181]]

the lowest possible level by whatever means available. The laboratory is 
responsible for maintaining a current awareness file of OSHA regulations 
regarding the safe handling of the chemicals specified in this method. A 
reference file of material data handling sheets should also be made 
available to all personnel involved in the chemical analysis. Additional 
references to laboratory safety are available and have been identified 
8-10 for the information of the analyst. Benzene and 2,3,7,8-TCDD 
have been identified as suspected human or mammalian carcinogens.
    4.2  Each laboratory must develop a strict safety program for 
handling 2,3,7,8-TCDD. The following laboratory practices are 
recommended:
    4.2.1  Contamination of the laboratory will be minimized by 
conducting all manipulations in a hood.
    4.2.2  The effluents of sample splitters for the gas chromatograph 
and roughing pumps on the GC/MS should pass through either a column of 
activated charcoal or be bubbled through a trap containing oil or high-
boiling alcohols.
    4.2.3  Liquid waste should be dissolved in methanol or ethanol and 
irradiated with ultraviolet light with a wavelength greater than 290 nm 
for several days. (Use F 40 BL lamps or equivalent). Analyze liquid 
wastes and dispose of the solutions when 2,3,7,8-TCDD can no longer be 
detected.
    4.3  Dow Chemical U.S.A. has issued the following precautimns 
(revised November 1978) for safe handling of 2,3,7,8-TCDD in the 
laboratory:
    4.3.1  The following statements on safe handling are as complete as 
possible on the basis of available toxicological information. The 
precautions for safe handling and use are necessarily general in nature 
since detailed, specific recommendations can be made only for the 
particular exposure and circumstances of each individual use. Inquiries 
about specific operations or uses may be addressed to the Dow Chemical 
Company. Assistance in evaluating the health hazards of particular plant 
conditions may be obtained from certain consulting laboratories and from 
State Departments of Health or of Labor, many of which have an 
industrial health service. 2,3,7,8-TCDD is extremely toxic to laboratory 
animals. However, it has been handled for years without injury in 
analytical and biological laboratories. Techniques used in handling 
radioactive and infectious materials are applicable to 2,3,7,8,-TCDD.
    4.3.1.1  Protective equipment--Throw-away plastic gloves, apron or 
lab coat, safety glasses, and a lab hood adequate for radioactive work.
    4.3.1.2  Training--Workers must be trained in the proper method of 
removing contaminated gloves and clothing without contacting the 
exterior surfaces.
    4.3.1.3  Personal hygiene--Thorough washing of hands and forearms 
after each manipulation and before breaks (coffee, lunch, and shift).
    4.3.1.4  Confinement--Isolated work area, posted with signs, 
segregated glassware and tools, plastic-backed absorbent paper on 
benchtops.
    4.3.1.5  Waste--Good technique includes minimizing contaminated 
waste. Plastic bag liners should be used in waste cans. Janitors must be 
trained in the safe handling of waste.
    4.3.1.6  Disposal of wastes--2,3,7,8-TCDD decomposes above 800 
deg.C. Low-level waste such as absorbent paper, tissues, animal remains, 
and plastic gloves may be burned in a good incinerator. Gross quantities 
(milligrams) should be packaged securely and disposed through commercial 
or governmental channels which are capable of handling high-level 
radioactive wastes or extremely toxic wastes. Liquids should be allowed 
to evaporate in a good hood and in a disposable container. Residues may 
then be handled as above.
    4.3.1.7  Decontamination--For personal decontamination, use any mild 
soap with plenty of scrubbing action. For decontamination of glassware, 
tools, and surfaces, Chlorothene NU Solvent (Trademark of the Dow 
Chemical Company) is the least toxic solvent shown to be effective. 
Satisfactory cleaning may be accomplished by rinsing with Chlorothene, 
then washing with any detergent and water. Dishwater may be disposed to 
the sewer. It is prudent to minimize solvent wastes because they may 
require special disposal through commercial sources which are expensive.
    4.3.1.8  Laundry--Clothing known to be contaminated should be 
disposed with the precautions described under Section 4.3.1.6. Lab coats 
or other clothing worn in 2,3,7,8-TCDD work areas may be laundered.
    Clothing should be collected in plastic bags. Persons who convey the 
bags and launder the clothing should be advised of the hazard and 
trained in proper handling. The clothing may be put into a washer 
without contact if the launderer knows the problem. The washer should be 
run through a cycle before being used again for other clothing.
    4.3.1.9  Wipe tests--A useful method of determining cleanliness of 
work surfaces and tools is to wipe the surface with a piece of filter 
paper. Extraction and analysis by gas chromatography can achieve a limit 
of sensitivity of 0.1 g per wipe. Less than 1 g of 
2,3,7,8-TCDD per sample indicates acceptable cleanliness; anything 
higher warrants further cleaning. More than 10 g on a wipe 
sample constitutes an acute hazard and requires prompt cleaning before 
further use of the equipment or work space. A high (>10 g)

[[Page 182]]

2,3,7,8-TCDD level indicates that unacceptable work practices have been 
employed in the past.
    4.3.1.10  Inhalation--Any procedure that may produce airborne 
contamination must be done with good ventilation. Gross losses to a 
ventilation system must not be allowed. Handling of the dilute solutions 
normally used in analytical and animal work presents no inhalation 
hazards except in the case of an accident.
    4.3.1.11  Accidents--Remove contaminated clothing immediately, 
taking precautions not to contaminate skin or other articles. Wash 
exposed skin vigorously and repeatedly until medical attention is 
obtained.

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete or composite sampling.
    5.1.1  Grab sample bottle--1-L or 1-qt, amber glass, fitted with a 
screw cap lined with Teflon. Foil may be substituted for Teflon if the 
sample is not corrosive. If amber bottles are not available, protect 
samples from light. The bottle and cap liner must be washed, rinsed with 
acetone or methylene chloride, and dried before use to minimize 
contamination.
    5.1.2  Automatic sampler (optional)--The sampler must incorporate 
glass sample containers for the collection of a minimum of 250 mL of 
sample. Sample containers must be kept refrigerated at 4  deg.C and 
protected from light during compositing. If the sampler uses a 
peristaltic pump, a minimum length of compressible silicone rubber 
tubing may be used. Before use, however, the compressible tubing should 
be thoroughly rinsed with methanol, followed by repeated rinsings with 
distilled water to minimize the potential for contamination of the 
sample. An integrating flow meter is required to collect flow 
proportional composites.
    5.1.3  Clearly label all samples as ``POISON'' and ship according to 
U.S. Department of Transportation regulations.
    5.2  Glassware (All specifications are suggested. Catalog numbers 
are included for illustration only.):
    5.2.1  Separatory funnels--2-L and 125-mL, with Teflon stopcock.
    5.2.2  Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes 
K-570050-1025 or equivalent). Calibration must be checked at the volumes 
employed in the test. Ground glass stopper is used to prevent 
evaporation of extracts.
    5.2.3  Evaporative flask, Kuderna-Danish--500-mL (Kontes K-570001-
0500 or equivalent). Attach to concentrator tube with springs.
    5.2.4  Snyder column, Kuderna-Danish--Three-ball macro (Kontes K-
503000-0121 or equivalent).
    5.2.5  Snyder column, Kuderna-Danish--Two-ball micro (Kontes K-
569001-0219 or equivalent).
    5.2.6  Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
    5.2.7  Chromatographic column--300 mm long  x  10 mm ID, with Teflon 
stopcock and coarse frit filter disc at bottom.
    5.2.8  Chromatographic column--400 mm long  x  11 mm ID, with Teflon 
stopcock and coarse frit filter disc at bottom.
    5.3  Boiling chips--Approximately 10/40 mesh. Heat to 400  deg.C for 
30 min or Soxhlet extract with methylene chloride.
    5.4  Water bath--Heated, with concentric ring cover, capable of 
temperature control (2  deg.C). The bath should be used in a 
hood.
    5.5  GC/MS system:
    5.5.1  Gas chromatograph--An analytical system complete with a 
temperature programmable gas chromatograph and all required accessories 
including syringes, analytical columns, and gases. The injection port 
must be designed for capillary columns. Either split, splitless, or on-
column injection techniques may be employed, as long as the requirements 
of Section 7.1.1 are achieved.
    5.5.2  Column--60 m long  x  0.25 mm ID glass or fused silica, 
coated with SP-2330 (or equivalent) with a film thickness of 0.2 
m. Any equivalent column must resolve 2, 3, 7, 8-TCDD from the 
other 21 TCDD isomers.16
    5.5.3  Mass spectrometer--Either a low resolution mass spectrometer 
(LRMS) or a high resolution mass spectrometer (HRMS) may be used. The 
mass spectrometer must be equipped with a 70 V (nominal) ion source and 
be capable of aquiring m/z abundance data in real time selected ion 
monitoring (SIM) for groups of four or more masses.
    5.5.4  GC/MS interface--Any GC to MS interface can be used that 
achieves the requirements of Section 7.1.1. GC to MS interfaces 
constructed of all glass or glass-lined materials are recommended. Glass 
surfaces can be deactivated by silanizing with dichlorodimethylsilane. 
To achieve maximum sensitivity, the exit end of the capillary column 
should be placed in the ion source. A short piece of fused silica 
capillary can be used as the interface to overcome problems associated 
with straightening the exit end of glass capillary columns.
    5.5.5  The SIM data acquired during the chromatographic program is 
defined as the Selected Ion Current Profile (SICP). The SICP can be 
acquired under computer control or as a real time analog output. If 
computer control is used, there must be software available to plot the 
SICP and report peak height or area data for any m/z in the SICP between 
specified time or scan number limits.
    5.6  Balance--Analytical, capable of accurately weighing 0.0001 g.

                               6. Reagents

    6.1  Reagent water--Reagent water is defined as a water in which an 
interferent is not observed at the MDL of 2, 3, 7, 8-TCDD.

[[Page 183]]

    6.2  Sodium hydroxide solution (10 N)--Dissolve 40 g of NaOH (ACS) 
in reagent water and dilute to 100 mL. Wash the solution with methylene 
chloride and hexane before use.
    6.3  Sodium thiosulfate--(ACS) Granular.
    6.4  Sulfuric acid--Concentrated (ACS, sp. gr. 1.84).
    6.5  Acetone, methylene chloride, hexane, benzene, ortho-xylene, 
tetradecane--Pesticide quality or equivalent.
    6.6  Sodium sulfate--(ACS) Granular, anhydrous. Purify by heating at 
400  deg.C for 4 h in a shallow tray.
    6.7  Alumina--Neutral, 80/200 mesh (Fisher Scientific Co., No. A-540 
or equivalent). Before use, activate for 24 h at 130  deg.C in a foil-
covered glass container.
    6.8  Silica gel--High purity grade, 100/120 mesh (Fisher Scientific 
Co., No. S-679 or equivalent).
    6.9  Stock standard solutions (1.00 g/L)--Stock 
standard solutimns can be prepared from pure standard materials or 
purchased as certified solutions. Acetone should be used as the solvent 
for spiking solutions; ortho-xylene is recommended for calibration 
standards for split injectors; and tetradecane is recommended for 
splitless or on-colum injectors. Analyze stock internal standards to 
verify the absence of native 2,3,7,8-TCDD.
    6.9.1  Prepare stock standard solutions of 2,3,7,8-TCDD (mol wt 320) 
and either 37C14 2,3,7,8-TCDD (mol wt 328) or 13C112 
2,3,7,8-TCDD (mol wt 332) in an isolated area by accurately weighing 
about 0.0100 g of pure material. Dissolve the material in pesticide 
quality solvent and dilute to volume in a 10-mL volumetric flask. When 
compound purity is assayed to be 96% or greater, the weight can be used 
without correction to calculate the concentration of the stock standard. 
Commercially prepared stock standards can be used at any concentration 
if they are certified by the manufacturer or by an independent source.
    6.9.2  Transfer the stock standard solutions into Teflon-sealed 
screw-cap bottles. Store in an isolated refrigerator protected from 
light. Stock standard solutions should be checked frequently for signs 
of degradation or evaporation, especially just prior to preparing 
calibration standards or spiking solutions from them.
    6.9.3  Stock standard solutions must be replaced after six months, 
or sooner if comparison with check standards indicates a problem.
    6.10  Internal standard spiking solution (25 ng/mL)--Using stock 
standard solution, prepare a spiking solution in acetone of 
either13Cl12 or 37Cl4 2,3,7,8-TCDD at a 
concentration of 25 ng/mL. (See Section 10.2)
    6.11  Quality control check sample concentrate--See Section 8.2.1.

                             7.  Calibration

    7.1  Establish gas chromatograhic operating conditions equivalent to 
those given in Table 1 and SIM conditions for the mass spectrometer as 
described in Section 12.2 The GC/MS system must be calibrated using the 
internal standard technique.
    7.1.1  Using stock standards, prepare calibration standards that 
will allow measurement of relative response factors of at least three 
concentration ratios of 2,3,7,8-TCDD to internal standard. Each 
calibration standard must be prepared to contain the internal standard 
at a concentration of 25 ng/mL. If any interferences are contributed by 
the internal standard at m/z 320 and 322, its concentration may be 
reduced in the calibration standards and in the internal standard 
spiking solution (Section 6.10). One of the calibration standards should 
contain 2,3,7,8-TCDD at a concentration near, but above, the MDL and the 
other 2,3,7,8-TCDD concentrations should correspond to the expected 
range of concentrations found in real samples or should define the 
working range of the GC/MS system.
    7.1.2  Using injections of 2 to 5 L, analyze each 
calibration standardaccording to Section 12 and tabulate peak height or 
area response against the concentration of 2,3,7,8-TCDD and internal 
standard. Calculate response factors (RF) for 2,3,7,8-TCDD using 
Equation 1.

                                                                        
                                           (As) (Cis)                   
                                   RF=   --------------                 
                                           (Ais) (Cs)                   
                                                                        

                                                              Equation 1
where:
    As=SIM response for 2,3,7,8-TCDD m/z 320.
    Ais=SIM response for the internal standard, m/z 332 for 
13C12 2,3,7,8-TCDD m/z 328 for 37Cl4 2,3,7,8-TCDD.
    Cis=Concentration of the internal standard (g/L).
    Cs=Concentration of 2,3,7,8-TCDD (g/L).

If the RF value over the working range is a constant (< 10% relative 
standard deviation, RSD), the RF can be assumed to be invariant and the 
average RF can be used for calculations. Alternatively, the results can 
be used to plot a calibration curve of response ratios, As/
Ais, vs. RF.
    7.1.3  The working calibration curve or RF must be verified on each 
working day by the measurement of one or more 2,3,7,8-TCDD calibration 
standards. If the response for 2,3,7,8-TCDD varies from the predicted 
response by more than 15%, the test must be repeated using a 
fresh calibration standard. Alternatively, a new calibration curve must 
be prepared.

[[Page 184]]

    7.2  Before using any cleanup procedure, the analyst must process a 
series of calibration standards through the procedure to validate 
elution patterns and the absence of interferences from the reagents.

                           8. Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality control program. The minimum requirements of this program 
consist of an initial demonstration of laboratory capability and an 
ongoing analysis of spiked samples to evaluate and document data 
quality. The laboratory must maintain records to document the quality of 
data that is generated. Ongoing data quality checks are compared with 
established performance criteria to determine if the results of analyses 
meet the performance characteristics of the method. When results of 
sample spikes indicate atypical method performance, a quality control 
check standard must be analyzed to confirm that the measurements were 
performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occurring in 
chromatography, the analyst is permitted certain options (detailed in 
Sections 10.5, 11.1, and 12.1) to improve the separations or lower the 
cost of measurements. Each time such a modification is made to the 
method, the analyst is required to repeat the procedure in Section 8.2
    8.1.3  Before processing any samples, the analyst must analyze a 
reagent water blank to demonstrate that interferences from the 
analytical system and glassware are under control. Each time a set of 
samples is extracted or reagents are changed, a reagent water blank must 
be processed as a safeguard against laboratory contamination.
    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 10% of all samples with native 2,3,7,8-TCDD to monitor and 
evaluate laboratory data quality. This procedure is described in Section 
8.3.
    8.1.5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 10% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.5.
    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality control (QC) check sample concentrate is required 
containing 2,3,7,8-TCDD at a concentration of 0.100 g/mL in 
acetone. The QC check sample concentrate must be obtained from the U.S. 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory in Cincinnati, Ohio, if available. If not available from that 
source, the QC check sample concentrate must be obtained from another 
external source. If not available from either source above, the QC check 
sample concentrate must be prepared by the laboratory using stock 
standards prepared independently from those used for calibration.
    8.2.2  Using a pipet, prepare QC check samples at a concentration of 
0.100 g/L (100 ng/L) by adding 1.00 mL of QC check sample 
concentrate to each of four 1-L aliquots of reagent water.
    8.2.3  Analyze the well-mixed QC check samples according to the 
method beginning in Section 10.
    8.2.4  Calculate the average recovery (X) in g/L, and the 
standard deviation of the recovery (s) in g/L, for 2,3,7,8-TCDD 
using the four results.
    8.2.5  Compare s and (X) with the corresponding acceptance criteria 
for precision and accuracy, respectively, found in Table 2. If s and X 
meet the acceptance criteria, the system performance is acceptable and 
analysis of actual samples can begin. If s exceeds the precision limit 
or X falls outside the range for accuracy, the system performance is 
unacceptable for 2,3,7,8-TCDD. Locate and correct the source of the 
problem and repeat the test beginning with Section 8.2.2.
    8.3  The laboratory must, on an ongoing basis, spike at least 10% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing one to ten samples per month, at least one 
spiked sample per month is required.
    8.3.1  The concentration of the spike in the sample should be 
determined as follows:
    8.3.1.1  If, as in compliance monitoring, the concentration of 
2,3,7,8-TCDD in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of 2,3,7,8-TCDD in the sample is not 
being checked against a limit specific to that parameter, the spike 
should be at 0.100 g/L or 1 to 5 times higher than the 
background concentration determined in Section 8.3.2, whichever 
concentration would be larger.
    8.3.1.3  If it is impractical to determine background levels before 
spiking (e.g., maximum holding times will be exceeded), the

[[Page 185]]

spike concentration should be (1) the regulatory concentration limit, if 
any; or, if none (2) the larger of either 5 times higher than the 
expected background concentration or 0.100 g/L.
    8.3.2  Analyze one sample aliquot to determine the background 
concentration (B) of 2,3,7,8-TCDD. If necessary, prepare a new QC check 
sample concentrate (Section 8.2.1) appropriate for the background 
concentration in the sample. Spike a second sample aliquot with 1.0 mL 
of the QC check sample concentrate and analyze it to determine the 
concentration after spiking (A) of 2,3,7,8-TCDD. Calculate percent 
recovery (P) as 100(A-B)%T, where T is the known true value of the 
spike.
    8.3.3  Compare the percent recovery (P) for 2,3,7,8-TCDD with the 
corresponding QC acceptance criteria found in Table 2. These acceptance 
criteria were calculated to include an allowance for error in 
measurement of both the background and spike concentrations, assuming a 
spike to background ratio of 5:1. This error will be accounted for to 
the extent that the analyst's spike to background ratio approaches 
5:1.11 If spiking was performed at a concentration lower than 0.100 
g/L, the analyst must use either the QC acceptance criteria in 
Table 2, or optional QC acceptance criteria calculated for the specific 
spike concentration. To calculate optional acceptance criteria for the 
recovery of 2,3,7,8-TCDD: (1) Calculate accuracy (X') using the equation 
in Table 3, substituting the spike concentration (T) for C; (2) 
calculate overall precision (S') using the equation in Table 3, 
substituting X' for X; (3) calculate the range for recovery at the spike 
concentration as (100 X'/T)2.44(100 S'/T)%. 11
    8.3.4  If the recovery of 2,3,7,8-TCDD falls outside the designated 
range for recovery, a check standard must be analyzed as described in 
Section 8.4.
    8.4  If the recovery of 2,3,7,8-TCDD fails the acceptance criteria 
for recovery in Section 8.3, a QC check standard must be prepared and 
analyzed.
    Note: The frequency for the required analysis of a QC check standard 
will depend upon the complexity of the sample matrix and the performance 
of the laboratory.
    8.4.1  Prepare the QC check standard by adding 1.0 mL of QC check 
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water.
    8.4.2  Analyze the QC check standard to determine the concentration 
measured (A) of 2,3,7,8-TCDD. Calculate the percent recovery (Ps) 
as 100 (A/T)%, where T is the true value of the standard concentration.
    8.4.3  Compare the percent recovery (Ps) with the corresponding 
QC acceptance criteria found in Table 2. If the recovery of 2,3,7,8-TCDD 
falls outside the designated range, the laboratory performance is judged 
to be out of control, and the problem must be immediately identified and 
corrected. The analytical result for 2,3,7,8-TCDD in the unspiked sample 
is suspect and may not be reported for regulatory compliance purposes.
    8.5  As part of the QC program for the laboratory, method accuracy 
for wastewater samples must be assessed and records must be maintained. 
After the analysis of five spiked wastewater samples as in Section 8.3, 
calculate the average percent recovery (P) and the spandard deviation of 
the percent recovery (sp). Express the accuracy assessment as a 
percent recovery interval from P-2sp to P+2sp. If P=90% and 
sp=10%, for example, the accuracy interval is expressed as 70-110%. 
Update the accuracy assessment on a regular basis (e.g. after each five 
to ten new accuracy measurements).
    8.6  It is recommended that the laboratory adopt additional quality 
assurance practices for use with this method. The specific practices 
that are most productive depend upon the needs of the laboratory and the 
nature of the samples. Field duplicates may be analyzed to assess the 
precision of the environmental measurements. Whenever possible, the 
laboratory should analyze standard reference materials and participate 
in relevant performance evaluation studies.

            9. Sample Collection, Preservation, and Handling

    9.1  Grab samples must be collected in glass containers. 
Conventional sampling practices 12 should be followed, except that 
the bottle must not be prerinsed with sample before collection. 
Composite samples should be collected in refrigerated glass containers 
in accordance with the requirements of the program. Automatic sampling 
equipment must be as free as possible of Tygon tubing and other 
potential sources of contamination.
    9.2  All samples must be iced or refrigerated at 4  deg.C and 
protected from light from the time of collection until extraction. Fill 
the sample bottles and, if residual chlorine is present, add 80 mg of 
sodium thiosulfate per liter of sample and mix well. EPA Methods 330.4 
and 330.5 may be used for measurement of residual chlorine.13 Field 
test kits are available for this purpose.
    9.3  Label all samples and containers ``POISON'' and ship according 
to applicable U.S. Department of Transportation regulations.
    9.4  All samples must be extracted within 7 days of collection and 
completely analyzed within 40 days of extraction.2

                          10. Sample Extraction

    Caution: When using this method to analyze for 2,3,7,8-TCDD, all of 
the following operations must be performed in a limited-access 
laboratory with the analyst wearing full

[[Page 186]]

protective covering for all exposed skin surfaces. See Section 4.2.
    10.1  Mark the water meniscus on the side of the sample bottle for 
later determination of sample volume. Pour the entire sample into a 2-L 
separatory funnel.
    10.2  Add 1.00 mL of internal standard spiking solution to the 
sample in the separatory funnel. If the final extract will be 
concentrated to a fixed volume below 1.00 mL (Section 12.3), only that 
volume of spiking solution should be added to the sample so that the 
final extract will contain 25 ng/mL of internal standard at the time of 
analysis.
    10.3  Add 60 mL of methylene chloride to the sample bottle, seal, 
and shake 30 s to rinse the inner surface. Transfer the solvent to the 
separatory funnel and extract the sample by shaking the funnel for 2 
min. with periodic venting to release excess pressure. Allow the organic 
layer to separate from the water phase for a minimum of 10 min. If the 
emulsion interface between layers is more than one-third the vmlume of 
the solvent layer, the analyst must employ mechanical techniques to 
complete the phase separation. The optimum technique depends upon the 
sample, but may include stirring, filtration of the emulsion through 
glass wool, centrifugation, or other physical methods. Collect the 
methylene chloride extract in a 250-mL Erlenmeyer flask.
    10.4  Add a second 60-mL volume of methylene chloride to the sample 
bottle and repeat the extraction procedure a second time, combining the 
extracts in the Erlenmeyer flask. Perform a third extraction in the same 
manner.
    10.5  Assemble a Kuderna-Danish (K-D) concentrator by attaching a 
10-mL concentrator tube to a 500-mL evaporative flask. Other 
concentration devices or techniques may be used in place of the K-D 
concentrator if the requirements of Section 8.2 are met.
    10.6  Pour the combined extract into the K-D concentrator. Rinse the 
Erlenmeyer flask with 20 to 30 mL of methylele chloride to complete the 
quantitative transfer.
    10.7  Add one or two clean boiling chips to the evaporative flask 
and attach a three-ball Snyder column. Prewet the Snyder column by 
adding about 1 mL of methylene chloride to the top. Place the K-D 
apparatus on a hot water bath (60 to 65  deg.C) so that the concentrator 
tube is partially immersed in the hot water, and the entire lower 
rounded surface of the flask is bathed with hot vapor. Adjust the 
vertical position of the apparatus and the water temperature as required 
to complete the concentration in 15 to 20 min. At the proper rate of 
distillation the balls of the column will actively chatter but the 
chambers will not flood with condensed solvent. When the apparent volume 
of liquid reaches 1 mL, remove the K-D apparatus and allow it to drain 
and cool for at least 10 min.
    10.8  Momentarily remove the Snyder column, add 50 mL of hexane and 
a new boiling chip, and reattach the Snyder column. Raise the 
temperature of the water bath to 85 to 90 deg.C. Concentrate the extract 
as in Section 10.7, except use hexane to prewet the column. Remove the 
Snyder column and rinse the flask and its lower joint into the 
concentrator tube with 1 to 2 mL of hexane. A 5-mL syringe is 
recommended for this operation. Set aside the K-D glassware for reuse in 
Section 10.14.
    10.9  Pour the hexane extract from the concentrator tube into a 125-
mL separatory funnel. Rinse the concentrator tube four times with 10-mL 
aliquots of hexane. Combine all rinses in the 125-mL separatory funnel.
    10.10  Add 50 mL of sodium hydroxide solution to the funnel and 
shake for 30 to 60 s. Discard the aqueous phase.
    10.11  Perform a second wash of the organic layer with 50 mL of 
reagent water. Discard the aqueous phase.
    10.12  Wash the hexane layer with a least two 50-mL aliquots of 
concentrated sulfuric acid. Continue washing the hexane layer with 50-mL 
aliquots of concentrated sulfuric acid until the acid layer remains 
colorless. Discard all acid fractions.
    10.13  Wash the hexane layer with two 50-mL aliquots of reagent 
water. Discard the aqueous phases.
    10.14  Transfer the hexane extract into a 125-mL Erlenmeyer flask 
containing 1 to 2 g of anhydrous sodium sulfate. Swirl the flask for 30 
s and decant the hexane extract into the reassembled K-D apparatus. 
Complete the quantitative transfer with two 10-mL hexane rinses of the 
Erlenmeyer flask.
    10.15  Replace the one or two clean boiling chips and concentrate 
the extract to 6 to 10 mL as in Section 10.8.
    10.16  Add a clean boiling chip to the concentrator tube and attach 
a two-ball micro-Snyder column. Prewet the column by adding about 1 mL 
of hexane to the top. Place the micro-K-D apparatus on the water bath so 
that the concentrator tube is partially immersed in the hot water. 
Adjust the vertical position of the apparatus and the water temperature 
as required to complete the concentration in 5 to 10 min. At the proper 
rate of distillation the balls of the column will actively chatter but 
the chambers will not flood. When the apparent volume of liquid reaches 
about 0.5 mL, remove the K-D apparatus and allow it to drain and cool 
for at least 10 min. Remove the micro-Snyder column and rinse its lower 
joint into the concentrator tube with 0.2 mL of hexane.
    Adjust the extract volume to 1.0 mL with hexane. Stopper the 
concentrator tube and store refrigerated and protected from light if 
further processing will not be performed immediately. If the extract 
will be stored

[[Page 187]]

longer than two days, it should be transferred to a Teflon-sealed screw-
cap vial. If the sample extract requires no further cleanup, proceed 
with GC/MS analysis (Section 12). If the sample requires further 
cleanup, proceed to Section 11.
    10.17  Determine the original sample volume by refilling the sample 
bottle to the mark and transferring the liquid to a 1000-mL graduated 
cylinder. Record the sample volume to the nearest 5 mL.

                       11. Cleanup and Separation

    11.1  Cleanup procedures may not be necessary for a relatively clean 
sample matrix. If particular circumstances demand the use of a cleanup 
procedure, the analyst may use either procedure below or any other 
appropriate procedure.1,5-7 However, the analyst first must 
demonstrate that the requirements of Section 8.2 can be met using the 
method as revised to incorporate the cleanup procedure. Two cleanup 
column options are offered to the analyst in this section. The alumina 
column should be used first to overcome interferences. If background 
problems are still encountered, the silica gel column may be helpful.
    11.2  Alumina column cleanup for 2,3,7,8-TCDD:
    11.2.1  Fill a 300 mm long x 10 mm ID chromatographic column with 
activated alumina to the 150 mm level. Tap the column gently to settle 
the alumina and add 10 mm of anhydrous sodium sulfate to the top.
    11.2.2  Preelute the column with 50 mL of hexane. Adjust the elution 
rate to 1 mL/min. Discard the eluate and just prior to exposure of the 
sodium sulfate layer to the air, quantitatively transfer the 1.0-mL 
sample extract onto the column using two 2-mL portions of hexane to 
complete the transfer.
    11.2.3  Just prior to exposure of the sodium sulfate layer to the 
air, add 50 mL of 3% methylene chloride/95% hexane (V/V) and continue 
the elution of the column. Discard the eluate.
    11.2.4  Next, elute the column with 50 mL of 20% methylene chloride/
80% hexane (V/V) into a 500-mL K-D flask equipped with a 10-mL 
concentrator tube. Concentrate the collected fraction to 1.0 mL as in 
Section 10.16 and analyze by GC/MS (Section 12).
    11.3  Silica gel column cleanup for 2,3,7,8-TCDD:
    11.3.1  Fill a 400 mm long x 11 mm ID chromatmgraphic column with 
silica gel to the 300 mm level. Tap the column gently to settle the 
silica gel and add 10 mm of anhydrous sodium sulfate to the top.
    11.3.2  Preelute the column with 50 mL of 20% benzene/80% hexane (V/
V). Adjust the elution rate to 1 mL/min. Discard the eluate and just 
prior to exposure of the sodium sulfate layer to the air, quantitatively 
transfer the 1.0-mL sample extract onto the column using two 2-mL 
portions of 20% benzene/80% hexane to complete the transfer.
    11.3.3  Just prior to exposure of the sodium sulfate layer to the 
air, add 40 mL of 20% benzene/80% hexane to the column. Collect the 
eluate in a clean 500-mL K-D flask equipped with a 10-mL concentrator 
tube. Concentrate the collected fraction to 1.0 mL as in Section 10.16 
and analyze by GC/MS.

                           12. GC/MS Analysis

    12.1  Table 1 summarizes the recommended operating conditions for 
the gas chromatograph. Included in this table are retention times and 
MDL that can be achieved under these conditions. Other capillary columns 
or chromatographic conditions may be used if the requirements of 
Sections 5.5.2 and 8.2 are met.
    12.2  Analyze standards and samples with the mass spectrometer 
operating in the selected ion monitoring (SIM) mode using a dwell time 
to give at least seven points per peak. For LRMS, use masses at m/z 320, 
322, and 257 for 2,3,7,8-TCDD and either m/z 328 for 37Cl4 
2,3,7,8-TCDD or m/z 332 for 13C12 2,3,7,8-TCDD. For HRMS, use 
masses at m/z 319.8965 and 321.8936 for 2,3,7,8-TCDD and either m/z 
327.8847 for 37Cl4 2,3,7,8-TCDD or m/z 331.9367 for 
13C12 2,3,7,8-TCDD.
    12.3  If lower detection limits are required, the extract may be 
carefully evaporated to dryness under a gentle stream of nitrogen with 
the concentrator tube in a water bath at about 40  deg.C. Conduct this 
operation immediately before GC/MS analysis. Redissolve the extract in 
the desired final volume of ortho-xylene or tetradecane.
    12.4  Calibrate the system daily as described in Section 7.
    12.5  Inject 2 to 5 L of the sample extract into the gas 
chromatograph. The volume of calibration standard injected must be 
measured, or be the same as all sample injection volumes.
    12.6  The presence of 2,3,7,8-TCDD is qualitatively confirmed if all 
of the following criteria are achieved:
    12.6.1  The gas chromatographic column must resolve 2,3,7,8-TCDD 
from the other 21 TCDD isomers.
    12.6.2  The masses for native 2,3,7,8-TCDD (LRMS-m/z 320, 322, and 
257 and HRMS-m/z 320 and 322) and labeled 2,3,7,8-TCDD (m/z 328 or 332) 
must exhibit a simultaneous maximum at a retention time that matches 
that of native 2,3,7,8-TCDD in the calibration standard, with the 
performance specifications of the analytical system.
    12.6.3  The chlorine isotope ratio at m/z 320 and m/z 322 must agree 
to within10% of that in the calibration standard.
    12.6.4  The signal of all peaks must be greater than 2.5 times the 
noise level.
    12.7  For quantitation, measure the response of the m/z 320 peak for 
2,3,7,8-TCDD

[[Page 188]]

and the m/z 332 peak for 13C12 2,3,7,8-TCDD or the m/z 328 
peak for 37Cl4 2,3,7,8-TCDD.
    12.8  Co-eluting impurities are suspected if all criteria are 
achieved except those in Section 12.6.3. In this case, another SIM 
analysis using masses at m/z 257, 259, 320 and either m/a 328 or m/z 322 
can be performed. The masses at m/z 257 and m/z 259 are indicative of 
the loss of one chlorine and one carbonyl group from 2,3,7,8-TCDD. If 
masses m/z 257 and m/z 259 give a chlorine isotope ratio that agrees to 
within 10% of the same cluster in the calibration standards, 
then the presence of TCDD can be confirmed. Co-eluting DDD, DDE, and PCB 
residues can be confirmed, but will require another injection using the 
appropriate SIM masses or full repetitive mass scans. If the response 
for 37Cl4 2,3,7,8-TCDD at m/z 328 is too large, PCB 
contamination is suspected and can be confirmed by examining the 
response at both m/z 326 and m/z 328. The 37Cl4 2,3,7,8-TCDD 
internal standard gives negligible response at m/z 326. These pesticide 
residues can be removed using the alumina column cleanup procedure.
    12.9  If broad background interference restricts the sensitivity of 
the GC/MS analysis, the analyst should employ additional cleanup 
procedures and reanalyze by GC/MS.
    12.10  In those circumstances where these procedures do not yield a 
definitive conclusion, the use of high resolution mass spectrometry is 
suggested.5

                            13. Calculations

    13.1  Calculate the concentration of 2,3,7,8-TCDD in the sample 
using the response factor (RF) determined in Section 7.1.2 and Equation 
2.

                                                                                                                
                                                                           (A)(Vt)                              
                                        Concentration (g/  = -----------------                         
                                                    L)                     (Vi)(Vs)                             
                                                                                                                

                                                              Equation 2
where:'
    As=SIM response for 2,3,7,8-TCDD at m/z 320.
    Ais=SIM response for the internal standard at m/z 328 or 332.
    Is=Amount of internal standard added to each extract 
(g).
    Vo=Volume of water extracted (L).

    13.2  For each sample, calculate the percent recovery of the 
internal standard by comparing the area of the m/z peak measured in the 
sample to the area of the same peak in the calibration standard. If the 
recovery is below 50%, the analyst should review all aspects of his 
analytical technique.
    13.3  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

                         14. Method Performance

    14.1  The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the value is above zero.1 The MDL concentration 
listed in Table 1 was obtained using reagent water.14 The MDL 
actually achieved in a given analysis will vary depending on instrument 
sensitivity and matrix effects.
    14.2  This method was tested by 11 laboratories using reagent water, 
drinking water, surface water, and three industrial wastewaters spiked 
at six concentrations over the range 0.02 to 0.20 g/L.15 
Single operator precision, overall precision, and method accuracy were 
found to be directly related to the concentration of the parameter and 
essentially independent of the sample matrix. Linear equations to 
describe these relationships are presented in Table 3.

                               References

    1. 40 CFR part 136, appendix B.
    2. ``Determination of TCDD in Industrial and Municipal 
Wastewaters,'' EPA 600/4-82-028, National Technical Information Service, 
PB82-196882, Springfield, Virginia 22161, April 1982.
    3. Buser, H.R., and Rappe, C. ``High Resolution Gas Chromatography 
of the 22 Tetrachlorodibenzo-p-dioxin Isomers,'' Analytical Chemistry, 
52, 2257 (1980).
    4. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard 
Practices for Preparation of Sample Containers and for Preservation of 
Organic Constituents,'' American Society for Testing and Materials, 
Philadelphia.
    5. Harless, R. L., Oswald, E. O., and Wilkinson, M. K. ``Sample 
Preparation and Gas Chromatography/Mass Spectrometry Determination of 
2,3,7,8-Tetrachlorodibenzo-p-dioxin,'' Analytical Chemistry, 52, 1239 
(1980).
    6. Lamparski, L. L., and Nestrick, T. J. ``Determination of Tetra-, 
Hepta-, and Octachlorodibenzo-p-dioxin Isomers in Particulate Samples at 
Parts per Trillion Levels,'' Analytical Chemistry, 52, 2045 (1980).
    7. Longhorst, M. L., and Shadoff, L. A. ``Determination of Parts-
per-Trillion Concentrations of Tetra-, Hexa-, and Octachlorodibenzo-p-
dioxins in Human Milk,'' Analytical Chemistry, 52, 2037 (1980).
    8. ``Carcinogens--Working with Carcinogens,'' Department of Health, 
Education, and Welfare, Public Health Service, Center for Disease 
Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    9. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR 
part 1910), Occuptional Safety and Health Administration, OSHA 2206 
(Revised, January 1976).

[[Page 189]]

    10. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    11. Provost, L. P., and Elder, R. S., ``Interpretation of Percent 
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44 
used in the equation in Section 8.3.3 is two times the value 1.22 
derived in this report.)
    12. ASTM Annual Book of Standards, Part 31, D3370-76, ``Standard 
Practices for Sampling Water,'' American Society for Testing and 
Materials, Philadelphia.
    13. ``Methods, 330.4 (Titrimetric, DPD-FAS) and 330.5 
(Spectrophotometric DPD) for Chlorine, Total Residual,'' Methods for 
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory, Cincinnati, Ohio 45268, March 1979.
    14. Wong, A.S. et al. ``The Determination of 2,3,7,8-TCDD in 
Industrial and Municipal Wastewaters, Method 613, Part 1--Development 
and Detection Limits,'' G. Choudhay, L. Keith, and C. Ruppe, ed., 
Butterworth Inc., (1983).
    15. ``EPA Method Study 26, Method 613: 2,3,7,8-Tetrachlorodibenzo-p-
dioxin,'' EPA 600/4-84-037, National Technical Information Service, 
PB84-188879, Springfield, Virginia 22161, May 1984.

     Table 1--Chromatographic Conditions and Method Detection Limit     
------------------------------------------------------------------------
                                                               Method   
                                                 Retention    detection 
                   Parameter                        time        limit   
                                                   (min)    (g/
                                                                 L)     
------------------------------------------------------------------------
2,3,7,8-TCDD...................................       13.1        0.002 
------------------------------------------------------------------------
Column conditions: SP-2330 coated on a 60 m long  x  0.25 mm ID glass   
  column with hydrogen carrier gas at 40 cm/sec linear velocity,        
  splitless injection using tetradecane. Column temperature held        
  isothermal at 200C for 1 min, then programmed at 8C/min to 250 C and  
  held. Use of helium carrier gas will approximately double the         
  retention time.                                                       


                                   Table 2--QC Acceptance Criteria--Method 613                                  
----------------------------------------------------------------------------------------------------------------
                                                              Test conc.    Limit for s                   Range 
                         Parameter                           (g/  (g/    Range for X    for P,
                                                                  L)            L)       (g/L)   Ps (%)
----------------------------------------------------------------------------------------------------------------
2,3,7,8-TCDD...............................................       0.100        0.0276     0.0523-0.1226   45-129
----------------------------------------------------------------------------------------------------------------
s=Standard deviation of four recovery measurements, in g/L (Section 8.2.4).                            
X=Average recovery for four recovery measurements, in g/L (Section 8.2.4).                             
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).                                                 
                                                                                                                
Note: These criteria are based directly upon the method performance data in Table 3. Where necessary, the limits
  for recovery have been broadened to assure applicability of the limits to concentrations below those used to  
  develop Table 3.                                                                                              


                Table 3--Method Accuracy and Precision as Functions of Concentration--Method 613                
----------------------------------------------------------------------------------------------------------------
                                                         Accuracy, as       Single analyst,   Overall precision,
                      Parameter                           recovery, X        precision, sr    S  (/g/L)
                                                        (g/L)       (/L)                      
----------------------------------------------------------------------------------------------------------------
2,3,7,8-TCDD........................................       0.86C+0.00145       0.13X+0.00129       0.19X+0.00028
----------------------------------------------------------------------------------------------------------------
X=Expected recovery for one or more measurements. of a sample containing a concentration of C, in g/L. 
sr=Expected single analyst standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
S=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
C=True value for the concentration, in g/L.                                                            
X=Average recovery found for measurements of samples containing a concentration of C, in g/L.          

                         Method 624--Purgeables

                        1. Scope and Application

    1.1  This method covers the determination of a number of purgeable 
organics. The following parameters may be determined by this method:

------------------------------------------------------------------------
                                                    STORET              
                    Parameter                         No.      CAS No.  
------------------------------------------------------------------------
Benzene..........................................     34030      71-43-2
Bromodichloromethane.............................     32101      75-27-4
Bromoform........................................     32104      75-25-2
Bromomethane.....................................     34413      74-83-9
Carbon tetrachloride.............................     32102      56-23-5
Chlorobenzene....................................     34301     108-90-7
Chloroethane.....................................     34311      75-00-3
2-Chloroethylvinyl ether.........................     34576     110-75-8
Chloroform.......................................     32106      67-66-3
Chloromethane....................................     34418      74-87-3
Dibromochloromethane.............................     32105     124-48-1
1,2-Dichlorobenzene..............................     34536      95-50-1
1,3-Dichlorobenzene..............................     34566     541-73-1
1,4-Dichlorobenzene..............................     34571     106-46-7
1,1-Dichloroethane...............................     34496      75-34-3
1,2-Dichloroethane...............................     34531     107-06-2
1,1-Dichloroethane...............................     34501      75-35-4
trans-1,2-Dichloroethene.........................     34546     156-60-5
1,2-Dichloropropane..............................     34541      78-87-5
cis-1,3-Dichloropropene..........................     34704   10061-01-5
trans-1,3-Dichloropropene........................     34699   10061-02-6
Ethyl benzene....................................     34371     100-41-4
Methylene chloride...............................     34423      75-09-2
1,1,2,2-Tetrachloroethane........................     34516      79-34-5
Tetrachloroethene................................     34475     127-18-4
Toluene..........................................     34010     108-88-3
1,1,1-Trichloroethene............................     34506      71-55-6
1,1,2-Trichloroethene............................     34511      79-00-5
Trichloroethane..................................     39180      79-01-6
Trichlorofluoromethane...........................     34488      75-69-4
Vinyl chloride...................................     39175      75-01-4
------------------------------------------------------------------------


[[Page 190]]

    1.2  The method may be extended to screen samples for acrolein 
(STORET No. 34210, CAS No. 107-02-8) and acrylonitrile (STORET No. 
34215, CAS No. 107-13-1), however, the preferred method for these two 
compounds in Method 603.
    1.3  This is a purge and trap gas chromatographic/mass spectrometer 
(GC/MS) method applicable to the determination of the compounds listed 
above in municipal and industrial discharges as provided under 40 CFR 
136.1.
    1.4  The method detection limit (MDL, defined in Section 14.1)\1\ 
for each parameter is listed in Table 1. The MDL for a specific 
wastewater may differ from those listed, depending upon the nature of 
interferences in the sample matrix.
    1.5  Any modification to this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5. Depending upon the nature of the modification and the extent 
of intended use, the applicant may be required to demonstrate that the 
modifications will produce equivalent results when applied to relevant 
wastewaters.
    1.6  This method is restricted to use by or under the supervision of 
analysts experienced in the operation of a purge and trap system and a 
gas chromatograph/mass spectrometer and in the interpretation of mass 
spectra. Each analyst must demonstrate the ability to generate 
acceptable results with this method using the procedure described in 
Section 8.2.

                          2. Summary of Method

    2.1  An inert gas is bubbled through a 5-mL water sample contained 
in a specially-designed purging chamber at ambient temperature. The 
purgeables are efficiently transferred from the aqueous phase to the 
vapor phase. The vapor is swept through a sorbent trap where the 
purgeables are trapped. After purging is completed, the trap is heated 
and backflushed with the inert gas to desorb the purgeables onto a gas 
chromatographic column. The gas chromatograph is temperature programmed 
to separate the purgeables which are then detected with a mass 
spectrometer.2,3

                            3. Interferences

    3.1  Impurities in the purge gas, organic compounds outgassing from 
the plumbing ahead of the trap, and solvent vapors in the laboratory 
account for the majority of contamination problems. The analytical 
system must be demonstated to be free from contamination under the 
conditions of the analysis by running laboratory reagent blanks as 
described in Section 8.1.3. The use of non-Teflon plastic tubing, non-
Teflon thread sealants, or flow controllers with rubber components in 
the purge and trap system should be avoided.
    3.2  Samples can be contaminated by diffusion of volatile organics 
(particularly fluorocarbons and methylene chloride) through the septum 
seal into the sample during shipment and storage. A field reagent blank 
prepared from reagent water and carried through the sampling and 
handling protocol can serve as a check on such contamination.
    3.3  Contamination by carry-over can occur whenever high level and 
low level samples are sequentially analyzed. To reduce carry-over, the 
purging device and sample syringe must be rinsed with reagent water 
between sample analyses. Whenever an unusually concentrated sample is 
encountered, it should be followed by an analysis of reagent water to 
check for cross contamination. For samples containing large amounts of 
water-soluble materials, suspended solids, high boiling compounds or 
high pureeable levels, it may be necessary to wash the purging device 
with a detergent solution, rinse it with distilled water, and then dry 
it in a 105  deg. C oven between analyses. The trap and other parts of 
the system are also subject to contamination; therefore, frequent 
bakeout and purging of the entire system may be required.

                                4. Safety

    4.1  The toxicity or carcinogenicity of each reagent used in this 
method has not been precisely defined; however, each chemical compound 
should be treated as a potential health hazard. From this viewpoint, 
exposure to these chemicals must be reduced to the lowest possible level 
by whatever means available. The laboratory is responsible for 
maintaining a current awareness file of OSHA regulations regarding the 
safe handling of the chemicals specified in this methmd. A reference 
file of material data handling sheets should also be made available to 
all personnel involved in the chemical analysis. Additional references 
to laboratory safety are available and have been identified4-6 for 
the information of the analyst.
    4.2.  The following parameters covered by this method have been 
tentatively classified as known or suspected, human or mammalian 
carcinogens: benzene, carbon tetrachloride, chloroform, 1,4-
dichlorobenzene, and vinyl chloride. Primary standards of these toxic 
compounds should be prepared in a hood. A NIOSH/MESA approved toxic gas 
respirator should be worn when the analyst handles high concentrations 
of these toxic compounds.

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete sampling.
    5.1.1  Vial--25-mL capacity or larger, equipped with a screw cap 
with a hole in the

[[Page 191]]

center (Pierce 13075 or equivalent). Detergent wash, rinse with tap and 
distilled water, and dry at 105  deg.C before use.
    5.1.2  Septum--Teflon-faced silicane (Pierce 12722 or equivalent). 
Detergent wash, rinse with tap and distilled water, and dry at 105 
deg.C for 1 h before use.
    5.2  Purge and trap system--The purge and trap system consists of 
three separate pieces of equipment: A purging device, trap, and 
desorber. Several complete systems are now commercially available.
    5.2.1  The purging device must be designed to accept 5-mL samples 
with a water column at least 3 cm deep. The gaseous head space between 
the water column and the trap must have a total volume of less than 15 
mL. The purge gas must pass though the water column as finely divided 
bubbles with a diameter of less than 3 mm at the origin. The purge gas 
must be introduced no more than 5 mm from the base of the water column. 
The purging device illustrated in Figure 1 meets these design criteria.
    5.2.2  The trap must be at least 25 cm long and have an inside 
diameter of at least 0.105 in. The trap must be packed to contain the 
following minimum lengths of adsorbents: 1.0 cm of methyl silicone 
coated packing (Section 6.3.2), 15 cm of 2,6-dyphenylene oxide polymer 
(Section 6.3.1), and 8 cm of silica gel (Section 6.3.3). The minimum 
specifications for the trap are illustrated in Figure 2.
    5.2.3  The desorber should be capable of rapidly heating the trap to 
180  deg.C. The polymer section of the trap should not be heated higher 
than 180  deg.C and the remaining sections should not exceed 200  deg.C. 
The desorber illustrated in Figure 2 meets these design criteria.
    5.2.4  The purge and trap system may be assembled as a separate unit 
or be coupled to a gas chromatograph as illustrated in Figures 3 and 4.
    5.3  GC/MS system:
    5.3.1  Gas chromatograph--An analytical system complete with a 
temperature programmable gas chromatograph suitable for on-column 
injection and all required accessories including syringes, analytical 
columns, and gases.
    5.3.2  Column--6 ft long x 0.1 in ID stainless steel or glass, 
packed with 1% SP-1000 on Carbopack B (60/80 mesh) or equivalent. This 
column was used to develop the method performance statements in Section 
14. Guidelines for the use of alternate column packings are provided in 
Section 11.1.
    5.3.3  Mass spectrometer--Capable of scanning from 20 to 260 amu 
every 7 s or less, utilizing 70 V (nominal) electron energy in the 
electron impact ionization mode, and producing a mass spectrum which 
meets all the criteria in Table 2 when 50 ng of 4-bromofluorobenzene 
(BFB) is injected through the GC inlet.
    5.3.4  GC/MS interface--Any GC to MS interface that gives acceptable 
calibration points at 50 ng or less per injection for each of the 
parameters of interest and achieves all acceptable performance criteria 
(Section 10) may be used. GC to MS interfaces constructed of all glass 
or glass-lined materials are recommended. Glass can be deactivated by 
silanizing with dichlorodimethylsilane.
    5.3.5  Data system--A computer system must be interfaced to the mass 
spectrometer that allows the continuous acquisition and storage on 
machine-readable media of all mass spectra obtained throughout the 
duration of the chromatographic program. The computer must have software 
that allows searching any GC/MS data file for specific m/z (masses) and 
plotting such m/z abundances versus time or scan number. This type of 
plot is defined as an Extracted Ion Current Profile (EICP). Software 
must also be available that allows integrating the abundance in any EICP 
between specified time or scan number limits.
    5.4  Syringes--5-mL, glass hypodermic with Luerlok tip (two each), 
if applicable to the purging device.
    5.5  Micro syringes--25-L, 0.006 in. ID needle.
    5.6  Syringe valve--2-way, with Luer ends (three each).
    5.7  Syringe--5-mL, gas-tight with shut-off valve.
    5.8  Bottle--15-mL, screw-cap, with Teflon cap liner.
    5.9  Balance--Analytical, capable of accurately weighing 0.0001 g.

                               6. Reagents

    6.1  Reagent water--Reagent water is defined as a water in which an 
interferent is not observed at the MDL of the parameters of interest.
    6.1.1  Reagent water can be generated by passing tap water through a 
carbon filter bed containing about 1 lb of activated carbon (Filtrasorb-
300, Calgon Corp., or equivalent).
    6.1.2  A water purification system (Millipore Super-Q or equivalent) 
may be used to generate reagent water.
    6.1.3  Reagent water may also be prepared by boiling water for 15 
min. Subsequently, while maintaining the temperature at 90  deg.C, 
bubble a contaminant-free inert gas through the water for 1 h. While 
still hot, transfer the water to a narrow mouth screw-cap bottle and 
seal with a Teflon-lined septum and cap.
    6.2  Sodium thiosulfate--(ACS) Granular.
    6.3  Trap materials:
    6.3.1  2,6-Diphenylene oxide polymer--Tenax, (60/80 mesh), 
chromatographic grade or equivalent.
    6.3.2  Methyl silicone packing--3% OV-1 on Chromosorb-W (60/80 mesh) 
or equivalent.
    6.3.3  Silica gel--35/60 mesh, Davison, grade-15 or equivalent.

[[Page 192]]

    6.4  Methanol--Pesticide quality or equivalent.
    6.5  Stock standard solutions--Stock standard solutions may be 
prepared from pure standard materials or purchased as certified 
solutions. Prepare stock standard solutions in methanol using assayed 
liquids or gases as appropriate. Because of the toxicity of some of the 
compounds, primary dilutions of these materials should be prepared in a 
hood. A NIOSH/MESA approved toxic gas respirator should be used when the 
analyst handles high concentrations of such materials.
    6.5.1  Place about 9.8 mL of methanol into a 10-mL ground glass 
stoppered volumetric flask. Allow the flask to stand, unstoppered, for 
about 10 min or until all alcohol wetted surfaces have dried. Weigh the 
flask to the nearest 0.1 mg.
    6.5.2  Add the assayed reference material:
    6.5.2.1  Liquids--Using a 100-L syringe, immediately add 
two or more drops of assayed reference material to the flask, then 
reweigh. Be sure that the drops fall directly into the alcohol without 
contacting the neck of the flask.
    6.5.2.2  Gases--To prepare standards for any of the four halocarbons 
that boil below 30  deg.C (bromomethane, chloroethane, chloromethane, 
and vinyl chloride), fill a 5-mL valved gas-tight syringe with the 
reference standard to the 5.0-mL mark. Lower the needle to 5 mm above 
the methanol meniscus. Slowly introduce the reference standard above the 
surface of the liquid (the heavy gas will rapidly dissolve in the 
methanol).
    6.5.3  Reweigh, dilute to volume, stopper, then mix by inverting the 
flask several times. Calculate the concentration in g/
L from the net gain in weight. When compound purity is assayed 
to be 96% or greater, the weight may be used without correction to 
calculate the concentration of the stock standard. Commercially prepared 
stock standards may be used at any concentration if they are certified 
by the manufacturer or by an independent source.
    6.5.4  Transfer the stock standard solution into a Teflon-sealed 
screw-cap bottle. Store, with minimal headspace, at -10 to -20  deg.C 
and protect from light.
    6.5.5  Prepare fresh standards weekly for the four gases and 2-
chloroethylvinyl ether. All other standards must be replaced after one 
month, or sooner if comparison with check standards indicates a problem.
    6.6  Secondary dilution standards--Using stock solutions, prepare 
secondary dilution standards in methanol that contain the compounds of 
interest, either singly or mixed together. The secondary dilution 
standards should be prepared at concentrations such that the aqueous 
calibration standards prepared in Section 7.3 will bracket the working 
range of the analytical system. Secondary dilution standards should be 
stored with minimal headspace and should be checked frequently for signs 
of degradation or evaporation, especially just prior to preparing 
calibration standards from them.
    6.7  Surrogate standard spiking solution--Select a minimum of three 
surrogate compounds from Table 3. Prepare stock standard solutions for 
each surrogate standard in methanol as described in Section 6.5. Prepare 
a surrogate standard spiking solution from these stock standards at a 
concentration of 15 g/mL in water. Store the solutions at 4 
deg.C in Teflon-sealed glass containers with a minimum of headspace. The 
solutions should be checked frequently for stability. The addition of 10 
L of this solution of 5 mL of sample or standard is equivalent 
to a concentration of 30 g/L of each surrogate standard.
    6.8  BFB Standard--Prepare a 25 g/mL solution of BFB in 
methanol.
    6.9  Quality control check sample concentrate--See Section 8.2.1.

                             7. Calibration

    7.1  Assemble a purge and trap system that meets the specifications 
in Section 5.2. Condition the trap overnight at 180  deg.C by 
backflushing with an inert gas flow of at least 20 mL/min. Condition the 
trap for 10 min once daily prior to use.
    7.2  Connect the purge and trap system to a gas chromatograph. The 
gas chromatograph must be operated using temperature and flow rate 
conditions equivalent to those given in Table 1.
    7.3  Internal standard calibration procedure--To use this approach, 
the analyst must select three or more internal standards that are 
similar in analytical behavior to the compounds of interest. The analyst 
must further demonstrate that the measurement of the internal standard 
is not affected by method or matrix interferences. Some recommended 
internal standards are listed in Table 3.
    7.3.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter by carefully adding 20.0 
L of one or more secondary dilution standards to 50, 250, or 
500 mL of reagent water. A 25-L syringe with a 0.006 in. ID 
needle should be used for this operation. One of the calibration 
standards should be at a concentration near, but above, the MDL (Table 
1) and the other concentrations should correspond to the expected range 
of concentrations found in real samples or should define the working 
range of the GC/MS system. These aqueous standards can be stored up to 
24 h, if held in sealed vials with zero headspace as described in 
Section 9.2. If not so stored, they must be discarded after 1 h.
    7.3.2  Prepare a spiking solution containing each of the internal 
standards using the procedures described in Sections 6.5 and 6.6. It is 
recommended that the secondary dilution standard be prepared at a 
concentration

[[Page 193]]

of 15 g/mL of each internal standard compound. The addition of 
10 L of this standard to 5.0 mL of sample or calibration 
standard would be equivalent to 30 g/L.
    7.3.3  Analyze each calibration standard according to Section 11, 
adding 10 L of internal standard spiking solution directly to 
the syringe (Section 11.4). Tabulate the area response of the 
characteristic m/z against concentration for each compound and internal 
standard, and calculate response factors (RF) for each compound using 
Equation 1.

                                                                        
                                            (As)(Cis)                   
                                   RF=   --------------                 
                                            (Ais)(Cs)                   
                                                                        

                                                              Equation 1
where:
    As=Area of the characteristic m/z for the parameter to be 
measured.
    Ais=Area of the characteristic m/z for the inernal standard.
    Cis=Concentration of the internal standard.
    Cs=Concentration of the parameter to be measured.
If the RF value over the working range is a constant (<35% RSD), the RF 
can be assumed to be invariant and the average RF can be used for 
calculations. Alternatively, the results can be used to plot a 
calibration curve of response ratios, As/Ais, vs. RF.
    7.4  The working calibration curve or RF must be verified on each 
working day by the measurement of a QC check sample.
    7.4.1  Prepare the QC check sample as described in Section 8.2.2.
    7.4.2  Analyze the QC check sample according to the method beginning 
in Section 10.
    7.4.3  For each parameter, compare the response (Q) with the 
corresponding calibration acceptance criteria found in Table 5. If the 
responses for all parameters of interest fall within the designated 
ranges, analysis of actual samples can begin. If any individual Q falls 
outside the range, proceed according to Section 7.4.4.

    Note: The large number of parameters in Table 5 present a 
substantial probability that one or more will not meet the calibration 
acceptance criteria when all parameters are analyzed.

    7.4.4  Repeat the test only for those parameters that failed to meet 
the calibration acceptance criteria. If the response for a parameter 
does not fall within the range in this second test, a new calibration 
curve or RF must be prepared for that parameter according to Section 
7.3.

                           8. Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality control program. The minimum requirements of this program 
consist of an initial demonstration of laboratory capability and an 
ongoing analysis of spiked samples to evaluate and document data 
quality. The laboratory must maintain records to document the quality of 
data that is generated. Ongoing data quality checks are compared with 
established performance criteria to determine if the results of analyses 
meet the performance characteristics of the method. When results of 
sample spikes indicate atypical method performance, a quality control 
check standard must be analyzed to confirm that the measurements were 
performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occurring in 
chromatography, the analyst is permitted certain options (detailed in 
Section 11.1) to improve the separations or lower the cost of 
measurements. Each time such a modification is made to the method, the 
analyst is required to repeat the procedure in Section 8.2.
    8.1.3  Each day, the analyst must analyze a reagent water blank to 
demonstrate that interferences from the analytical system are under 
control.
    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 5% of all samples to monitor and evaluate laboratory data 
quality. This procedure is described in Section 8.3.
    8.1.5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 5% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must spike all samples with surrogate 
standards to monitor continuing laboratory performance. This procedure 
is described in Section 8.5.
    8.1.7  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.6.
    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality control (QC) check sample concentrate is required 
containing each parameter of interest at a concentration of 10 
g/mL in methanol. The QC check sample concentrate must be 
obtained from the U.S. Environmental Protection Agency, Environmental 
Monitoring and Support Laboratory in Cincinnati, Ohio, if available. If 
not available from that source, the QC check sample concentrate must be 
obtained from another external source. If not available from either

[[Page 194]]

source above, the QC check sample concentrate must be prepared by the 
laboratory using stock standards prepared independently from those used 
for calibration.
    8.2.2  Prepare a QC check sample to contain 20 g/L of each 
parameter by adding 200 L of QC check sample concentrate to 100 
mL of reagent water.
    8.2.3  Analyze four 5-mL aliquots of the well-mixed QC check sample 
according to the method beginning in Section 10.
    8.2.4  Calculate the average recovery (X) in g/L, and the 
standard deviation of the recovery (s) in g/L, for each 
parameter of interest using the four results.
    8.2.5  For each parameter compare s and X with the corresponding 
acceptance criteria for precision and accuracy, respectively, found in 
Table 5. If s and X for all parameters of interest meet the acceptance 
criteria, the system performance is acceptable and analysis of actual 
samples can begin. If any individual s exceeds the precision limit or 
any individual X falls outside the range for accuracy, the system 
performance is unacceptable for that parameter.

    Note: The large number of parameters in Table 5 present a 
substantial probability that one or more will fail at least one of the 
acceptance criteria when all parameters are analyzed.

    8.2.6  When one or more of the parameters tested fail at least one 
of the acceptance criteria, the analyst must proceed according to 
Section 8.2.6.1 or 8.2.6.2.
    8.2.6.1  Locate and correct the source of the problem and repeat the 
test for all parameters of interest beginning with Section 8.2.3.
    8.2.6.2  Beginning with Section 8.2.3, repeat the test only for 
those parameters that failed to meet criteria. Repeated failure, 
however, will confirm a general problem with the measurement system. If 
this occurs, locate and correct the source of the problem and repeat the 
test for all compounds of interest beginning with Section 8.2.3.
    8.3  The laboratory must, on an ongoing basis, spike at least 5% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing 1 to 20 samples per month, at least one 
spiked sample per month is required.
    8.3.1  The concentration of the spike in the sample should be 
determined as follows:
    8.3.1.1  If, as in compliance monitoring, the concentration of a 
specific parameter in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of a specific parameter in the sample 
is not being checked against a limit specific to that parameter, the 
spike should be at 20 g/L or 1 to 5 times higher than the 
background concentration determined in Section 8.3.2, whichever 
concentration would be larger.
    8.3.2  Analyze one 5-mL sample aliquot to determine the background 
concentration (B) of each parameter. If necessary, prepare a new QC 
check sample concentrate (Section 8.2.1) appropriate for the background 
concentrations in the sample. Spike a second 5-mL sample aliquot with 10 
L of the QC check sample concentrate and analyze it to 
determine the concentration after spiking (A) of each parameter. 
Calculate each percent recovery (P) as 100(A-B)%/T, where T is the known 
true value of the spike.
    8.3.3  Compare the percent recovery (P) for each parameter with the 
corresponding QC acceptance criteria found in Table 5. These acceptance 
criteria wer calculated to include an allowance for error in measurement 
of both the background and spike concentrations, assuming a spike to 
background ratio of 5:1. This error will be accounted for to the extent 
that the analyst's spike to background ratio approaches 5:1.7 If 
spiking was performed at a concentration lower than 20 g/L, the 
analyst must use either the QC acceptance criteria in Table 5, or 
optional QC acceptance criteria calculated for the specific spike 
concentration. To calculate optional acceptance criteria for the 
recoveryof a parameter: (1) Calculate accuracy (X') using the equation 
in Table 6, substituting the spike concentration (T) for C; (2) 
calculate overall precision (S') using the equation in Table 6, 
substituting X' for X; (3) calculate the range for recovery at the spike 
concentration as (100 X'/T) (2.44(100 S'/T)%.7
    8.3.4  If any individual P falls outside the designated range for 
recovery, that parameter has failed the acceptance criteria. A check 
standard containing each parameter that failed the criteria must be 
analyzed as described in Section 8.4.
    8.4  If any parameter fails the acceptance criteria for recovery in 
Section 8.3, a QC check standard containing each parameter that failed 
must be prepared and analyzed.

    Note: The frequency for the required anlaysis of a QC check standard 
will depend upon the number of parameters being simultaneously tested, 
the complexity of the sample matrix, and the performance of the 
laboratory. If the entire list of parameters in Table 5 must be measured 
in the sample in Section 8.3, the probability that the analysis of a QC 
check standard will be required is high. In this case the QC check 
standard should be routinely analyzed with the spiked sample.

    8.4.1  Prepare the QC check standard by adding 10 L of QC 
check sample concentrate (Section 8.2.1 or 8.3.2) to 5 mL of reagent 
water. The QC check standard needs only to

[[Page 195]]

contain the parameters that failed criteria in the test in Section 8.3.
    8.4.2  Analyze the QC check standard to determine the concentration 
measured (A) of each parameter. Calculate each percent recovery 
(PS) as 100 (A/T)%, where T is the true value of the standard 
concentration.
    8.4.3  Compare the percent recovery (PS) for each parameter 
with the corresponding QC acceptance criteria found in Table 5. Only 
parameters that failed the test in Section 8.3 need to be compared with 
these criteria. If the recovery of any such parameter falls outside the 
designated range, the laboratory performance for that parameter is 
judged to be out of control, and the problem must be immediately 
identified and corrected. The analytical result for that parameter in 
the unspiked sample is suspect and may not be reported for regulatory 
compliance purposes.
    8.5  As a quality control check, the laboratory must spike all 
samples with the surrogate standard spiking solutions as described in 
Section 11.4, and calculate the percent recovery of each surrogate 
compound.
    8.6  As part of the QC program for the laboratory, method accuracy 
for wastewater samples must be assessed and records must be maintained. 
After the analysis of five spiked wastewater samples as in Section 8.3, 
calculate the average percent recovery (P) and the standard deviation of 
the percent recovery (sp). Express the accuracy assessment as a 
percent recovery interval from P--2sp to P + 2sp. If P=90% and 
sp=10%, for example, the accuracy interval is expressed as 70-110%. 
Update the accuracy assessment for each parameter a regular basis (e.g. 
after each five to ten new accuracy measurements).
    8.7  It is recommended that the laboratory adopt additional quality 
assurance practices for use with this method. The specific practices 
that are most productive depend upon the needs of the laboratory and the 
nature of the samples. Field duplicates may be analyzed to assess the 
precision of the environmental measurements. Whenever possible, the 
laboratory should analyze standard reference materials and participate 
in relevant performance evaluation studies.

            9. Sample Collection, Preservation, and Handling

    9.1  All samples must be iced or refrigerated from the time of 
collection until analysis. If the sample contains residual chlorine, add 
sodium thiosulfate preservative (10 mg/40 mL is sufficient for up to 5 
ppm Cl2) to the empty sample bottle just prior to shipping to the 
sampling site. EPA Methods 330.4 and 330.5 may be used for measurement 
of residual chlorine.\8\ Field test kits are available for this purpose.
    9.2  Grab samples must be collected in glass containers having a 
total volume of at least 25 mL. Fill the sample bottle just to 
overflowing in such a manner that no air bubbles pass through the sample 
as the bottle is being filled. Seal the bottle so that no air bubbles 
are entrapped in it. If preservative has been added, shake vigorously 
for 1 min. Maintain the hermetic seal on the sample bottle until time of 
analysis.
    9.3  Experimental evidence indicates that some aromatic compounds, 
notably benzene, toluene, and ethyl benzene are susceptible to rapid 
biological degradation under certain environmental conditions.\3\ 
Refrigeration alone may not be adequate to preserve these compounds in 
wastewaters for more than seven days. For this reason, a separate sample 
should be collected, acidified, and analyzed when these aromatics are to 
be determined. Collect about 500 mL of sample in a clean container. 
Adjust the pH of the sample to about 2 by adding 1+1 HCl while stirring 
vigorously, Check pH with narrow range (1.4 to 2.8) pH paper. Fill a 
sample container as described in Section 9.2.
    9.4  All samples must be analyzed within 14 days of collection.\3\

                    10. Daily GC/MS Performance Tests

    10.1  At the beginning of each day that analyses are to be 
performed, the GC/MS system must be checked to see if acceptable 
performance criteria are achieved for BFB.\9\ The performance test must 
be passed before any samples, blanks, or standards are analyzed, unless 
the instrument has met the DFTPP test described in Method 625 earlier in 
the day.\10\
    10.2  These performance tests require the following instrumental 
parameters:

    Electron Energy: 70 V (nominal)
    Mass Range: 20 to 260 amu
    Scan Time: To give at least 5 scans per peak but not to exceed 7 s 
per scan.

    10.3  At the beginning of each day, inject 2 L of BFB 
solution directly on the column. Alternatively, add 2 L of BFB 
solution to 5.0 mL of reagent water or standard solution and analyze the 
solution according to section 11. Obtain a background-corrected mass 
spectrum of BFB and confirm that all the key m/z criteria in Table 2 are 
achieved. If all the criteria are not achieved, the analyst must retune 
the mass spectrometer and repeat the test until all criteria are 
achieved.

                11. Sample Purging and Gas Chromatography

    11.1  Table 1 summarizes the recommended operating conditions for 
the gas chromatograph. Included in this table are retention times and 
MDL that can be achieved under these conditions. An example of the 
separations achieved by this column is shown in Figure 5. Other packed 
columns or chromatographic conditions may be used if the requirements of 
Section 8.2 are met.

[[Page 196]]

    11.2  After achieving the key m/z abundance criteria in Section 10, 
calibrate the system daiy as described in Section 7.
    11.3  Adjust the purge gas (helium) flow rate to 40 mL/min. Attach 
the trap inlet to the purging device, and set the purge and trap system 
to purge (Figure 3). Open the syringe valve located on the purging 
device sample introduction needle.
    11.4  Allow the sample to come to ambient temperature prior to 
introducing it into the syringe. Remove the plunger from a 5-mL syringe 
and attach a closed syringe valve. Open the sample bottle (or standard) 
and carefully pour the sample into the syringe barrel to just short of 
overflowing. Replace the syringe plunger and compress the sample. Open 
the syringe valve and vent any residual air while adjusting the sample 
volume to 5.0 mL. Since this process of taking an aliquot destroys the 
validity of the sample for future analysis, the analyst should fill a 
second syringe at this time to protect against possible loss of data. 
Add 10.0 L of the surrogate spiking solution (Section 6.7) and 
10.0 L of the internal standard spiking solution (Section 
7.3.2) through the valve bore, then close the valve. The surrogate and 
internal standards may be mixed and added as a single spiking solution.
    11.5  Attach the syringe-syringe valve assembly to the syringe valve 
on the purging device. Open the syringe valves and inject the sample 
into the purging chamber.
    11.6  Close both valves and purge the sample for 11.00.1 
min at ambient temperature.
    11.7  After the 11-min purge time, attach the trap to the 
chromatograph, adjust the purge and trap system to the desorb mode 
(Figure 4), and begin to temperature program the gas chromatograph. 
Introduce the trapped materials to the GC column by rapidly heating the 
trap to 180  deg.C while backflushing the trap with an inert gas between 
20 and 60 mL/min for 4 min. If rapid heating of the trap cannot be 
achieved, the GC cloumn must be used as a secondary trap by cooling it 
to 30  deg.C (subambient temperature, if problems persist) instead of 
the initial program temperature of 45  deg.C.
    11.8  While the trap is being desorbed into the gas chromatograph, 
empty the purging chamber using the sample introduction syringe. Wash 
the chamber with two 5-mL flushes of reagent water.
    11.9  After desorbing the sample for 4 min, recondition the trap by 
returning the purge and trap system to the purge mode. Wait 15 s then 
close the syringe valve on the purging device to begin gas flow through 
the trap. The trap temperature should be maintained at 180  deg.C. After 
approximately 7 min, turn off the trap heater and open the syringe valve 
to stop the gas flow through the trap. When the trap is cool, the next 
sample can be analyzed.
    11.10  If the response for any m/z exceeds the working range of the 
system, prepare a dilution of the sample with reagent water from the 
aliquot in the second syringe and reanalyze.

                     12. Qualitative Identification

    12.1  Obtain EICPs for the primary m/z (Table 4) and at least two 
secondary masses for each parameter of interest. The following criteria 
must be met to make a qualitative identification:
    12.1.1  The characteristic masses of each parameter of interest must 
maximize in the same or within one scan of each other.
    12.1.2  The retention time must fall within 30 s of the 
retention time of the authentic compound.
    12.1.3  The relative peak heights of the three characteristic masses 
in the EICPs must fall within  20% of the relative 
intensities of these masses in a reference mass spectrum. The reference 
mass spectrum can be obtained from a standard analyzed in the GC/MS 
system or from a reference library.
    12.2  Structural isomers that have very similar mass spectra and 
less than 30 s difference in retention time, can be explicitly 
identified only if the resolution between authentic isomers in a 
standard mix is acceptable. Acceptable resolution is achieved if the 
baseline to valley height between the isomers is less than 25% of the 
sum of the two peak heights. Otherwise, structural isomers are 
identified as isomeric pairs.

                            13. Calculations

    13.1  When a parameter has been identified, the quantitation of that 
parameter should be based on the integrated abundance from the EICP of 
the primary characteristic m/z given in Table 4. If the sample produces 
an interference for the primary m/z, use a secondary characteristic m/z 
to quantitate.
    Calculate the concentration in the sample using the response factor 
(RF) determined in Section 7.3.3 and Equation 2.

                                                                                                                
                                                                                                                
                                                                            (As)(Cis)                           
                                       Concentration (g/L)=   -------------------                      
                                                                            (Ais)(RF)                           
                                                                                                                

                                                              Equation 2
where:
    AS=Area of the characteristic m/z for the parameter or 
surrogate standard to be measured.
    Ais=Area of the characteristic m/z for the internal standard.
    Cis=Concentration of the internal standard.

    13.2  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

[[Page 197]]

                         14. Method Performance

    14.1  The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the value is above zero.1 The MDL concentrations 
listed in Table 1 were obtained using reagent water.11 Similar 
results were achieved using representative wastewaters. The MDL actually 
achieved in a given analysis will vary depending on instrument 
sensitivity and matrix effects.
    14.2  This method was tested by 15 laboratories using reagent water, 
drinking water, surface water, and industrial wastewaters spiked at six 
concentrations over the range 5-600 g/L.12 Single operator 
precision, overall precision, and method accuracy were found to be 
directly related to the concentration of the parameter and essentially 
independent of the sample matrix. Linear equations to describe these 
relationships are presented in Table 5.

                               References

    1. 40 CFR part 136, appendix B.
    2. Bellar, T.A., and Lichtenberg, J.J. ``Determining Volatile 
Organics at Microgram-per-Litre Levels by Gas Chromatography,'' Journal 
American Water Works Association, 66, 739 (1974).
    3. Bellar, T.A., and Lichtenberg, J.J. ``Semi-Automated Headspace 
Analysis of Drinking Waters and Industrial Waters for Purgeable Volatile 
Organic Compounds, '' Measurement of Organic Pollutants in Water and 
Wastewater, C.E. Van Hall, editor, American Society for Testing and 
Materials, Philadelphia, PA. Special Technical Publication 686, 1978.
    4. ``Carcinogens--Working With Carcinogens,'' Department of Health, 
Education, and Welfare, Public Health Service, Center for Disease 
Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    5. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR 
part 1910), Occupational Safety and Health Administration, OSHA 2206 
(Revised, January 1976).
    6. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent 
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44 
used in the equation in Section 8.2.3 is two times the value 1.22 
derived in this report.)
    8. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for 
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory, Cincinnati, Ohio 45268, March 1979.
    9. Budde, W.L., and Eichelberger, J.W. ``Performance Tests for the 
Evaluation of Computerized Eas Chromatography/Mass Spectrometry 
Equipment and Laboratories,'' EPA-600/4-80-025, U.S. Environmental 
Protection Agency, Environmental Monitoring and Support Laboratory, 
Cincinnati, Ohio 45268, April 1980.
    10. Eichelberger, J.W., Harris, L.E., and Budde, W.L. ``Reference 
Compound to Calibrate Ion Abundance Measurement in Gas Chromatography--
Mass Spectrometry Systems,'' Analytical Chemistry, 47, 995-1000 (1975).
    11. ``Method Detection Limit for Methods 624 and 625,'' Olynyk, P., 
Budde, W.L., and Eichelberger, J.W. Unpublished report, May 14, 1980.
    12. ``EPA Method Study 29 EPA Method 624--Purgeables,'' EPA 600/4-
84-054, National Technical Information Service, PB84-209915, 
Springfield, Virginia 22161, June 1984.
    13.``Method Performance Data for Method 624,'' Memorandum from R. 
Slater and T. Pressley, U.S. Environmental Protection Agency, 
Environmental Monitoring and Support Laboratory, Cincinnati, Ohio 45268, 
January 17, 1984.

     Table 1--Chromatographic Conditions and Method Detection Limits    
------------------------------------------------------------------------
                                                               Method   
                                                              detection 
                   Parameter                     Retention      limit   
                                                time (min)  (g/
                                                                 L)     
------------------------------------------------------------------------
Chloromethane.................................         2.3           nd 
Bromomethane..................................         3.1           nd 
Vinyl chloride................................         3.8           nd 
Chloroethane..................................         4.6           nd 
Methylene chloride............................         6.4          2.8 
Trichlorofluoromethane........................         8.3           nd 
1,1-Dichloroethene............................         9.0          2.8 
1,1-Dichloroethane............................        10.1          4.7 
trans-1,2-Dichloroethene......................        10.8          1.6 
Chloroform....................................        11.4          1.6 
1,2-Dichloroethane............................        12.1          2.8 
1,1,1-Trichloroethane.........................        13.4          3.8 
Carbon tetrachloride..........................        13.7          2.8 
Bromodichloromethane..........................        14.3          2.2 
1,2-Dichloroproane............................        15.7          6.0 
cis-1,3-Dichloropropene.......................        15.9          5.0 
Trichloroethene...............................        16.5          1.9 
Benzene.......................................        17.0          4.4 
Dibromochloromethane..........................        17.1          3.1 
1,1,2-Trichloroethane.........................        17.2          5.0 
trans-1,3-Dichloropropene.....................        17.2           nd 
2-Chloroethylvinlyl ether.....................        18.6           nd 
Bromoform.....................................        19.8          4.7 
1,1,2,2-Tetrachloroethane.....................        22.1          6.9 
Tetrachloroethene.............................        22.2          4.1 
Toluene.......................................        23.5          6.0 
Chlorobenzene.................................        24.6          6.0 
Ethyl benzene.................................        26.4          7.2 
1,3-Dichlorobenzene...........................        33.9           nd 
1,2-Dichlorobenzene...........................        35.0           nd 

[[Page 198]]

                                                                        
1,4-Dichlorobenzene...........................        35.4           nd 
------------------------------------------------------------------------
Column conditions: Carbopak B (60/80 mesh) coated with 1% SP-1000 packed
  in a 6 ft by 0.1 in. ID glass column with helium carrier gas at 30 mL/
  min. flow rate. Column temperature held at 45C for 3 min., then       
  programmed at 8C/min. to 220C and held for 15 min.                    
nd=not determined.                                                      


                 Table 2--BFB Key m/z Abundance Criteria                
------------------------------------------------------------------------
                   Mass                        m/z Abundance criteria   
------------------------------------------------------------------------
50........................................  15 to 40% of mass 95.       
75........................................  30 to 60% of mass 95.       
95........................................  Base Peak, 100% Relative    
                                             Abundance.                 
96........................................  5 to 9% of mass 95.         
173.......................................  <2% of mass 174.            
174.......................................  >50% of mass 95.            
175.......................................  5 to 9% of mass 174.        
176.......................................  >95% but < 101% of mass 174.
177.......................................  5 to 9% of mass 176.        
------------------------------------------------------------------------


           Table 3--Suggested Surrogate and Internal Standards          
------------------------------------------------------------------------
                                         Retention                      
                Compound                    time    Primary   Secondary 
                                           (min)a     m/z       masses  
------------------------------------------------------------------------
Benzene d-6............................     17.0        84   ...........
4-Bromofluorobenzene...................     28.3        95      174, 176
1,2-Dichloroethane d-4.................     12.1       102   ...........
1,4-Difluorobenzene....................     19.6       114        63, 88
Ethylbenzene d-5.......................     26.4       111   ...........
Ethylbenzene d-10......................     26.4        98   ...........
Fluorobenzene..........................     18.4        96            70
Pentafluorobenzene.....................     23.5       168   ...........
Bromochloromethane.....................      9.3       128   49, 130, 51
2-Bromo-1-chloropropane................     19.2        77       79, 156
1, 4-Dichlorobutane....................     25.8        55        90, 92
------------------------------------------------------------------------
aFor chromatographic conditions, see Table 1.                           


          Table 4--Characteristic Masses for Purgeable Organics         
------------------------------------------------------------------------
              Parameter                Primary          Secondary       
------------------------------------------------------------------------
Chloromethane........................      50   52.                     
Bromomethane.........................      94   96.                     
Vinyl chloride.......................      62   64.                     
Chloroethane.........................      64   66.                     
Methylene chloride...................      84   49, 51, and 86.         
Trichlorofluoromethane...............     101   103.                    
1,1-Dichloroethene...................      96   61 and 98.              
1,1-Dichloroethane...................      63   65, 83, 85, 98, and 100.
trans-1,2-Dichloroethene.............      96   61 and 98.              
Chloroform...........................      83   85.                     
1,2-Dichloroethane...................      98   62, 64, and 100.        
1,1,1-Trichloroethane................      97   99, 117, and 119.       
Carbon tetrachloride.................     117   119 and 121.            
Bromodichloromethane.................     127   83, 85, and 129.        
1,2-Dichloropropane..................     112   63, 65, and 114.        
trans-1,3-Dichloropropene............      75   77.                     
Trichloroethene......................     130   95, 97, and 132.        
Benzene..............................      78   ........................
Dibromochloromethane.................     127   129, 208, and 206.      
1,1,2-Trichloroethane................      97   83, 85, 99, 132, and    
                                                 134.                   
cis-1,3-Dichloropropene..............      75   77.                     
2-Chloroethylvinyl ether.............     106   63 and 65.              
Bromoform............................     173   171, 175, 250, 252, 254,
                                                 and 256.               
1,1,2,2-Tetrachloroethane............     168   83, 85, 131, 133, and   
                                                 166.                   
Tetrachloroethene....................     164   129, 131, and 166.      
Toluene..............................      92   91.                     
Chlorobenzene........................     112   114.                    
Ethyl benzene........................     106   91.                     
1,3-Dichlorobenzene..................     146   148 and 113.            
1,2-Dichlorobenzene..................     146   148 and 113.            
1,4-Dichlorobenzene..................     146   148 and 113.            
------------------------------------------------------------------------


                          Table 5--Calibration and QC Acceptance Criteria--Method 624a                          
----------------------------------------------------------------------------------------------------------------
                                                       Range for Q   Limit for s    Range for X                 
                     Parameter                        (/g/  (/   (/g/   Range for P, 
                                                           L)            g/L)           L)            Ps (%)    
----------------------------------------------------------------------------------------------------------------
Benzene............................................       12.8-27.2         6.9        15.2-26.0          37-151
Bromodichloromethane...............................       13.1-26.9         6.4        10.1-28.0          35-155
Bromoform..........................................       14.2-25.8         5.4        11.4-31.1          45-169
Bromomethane.......................................        2.8-37.2        17.9           D-41.2           D-242
Carbon tetrachloride...............................       14.6-25.4         5.2        17.2-23.5          70-140
Chlorobenzene......................................       13.2-26.8         6.3        16.4-27.4          37-160
Chloroethane.......................................        7.6-32.4        11.4         8.4-40.4          14-230
2-Chloroethylvinyl ether...........................          D-44.8        25.9           D-50.4           D-305
Chloroform.........................................       13.5-26.5         6.1        13.7-24.2          51-138
Chloromethane......................................          D-40.8        19.8           D-45.9           D-273
Dibromochloromethane...............................       13.5-26.5         6.1        13.8-26.6          53-149
1,2-Dichlorobenzene................................       12.6-27.4         7.1        11.8-34.7          18-190
1,3-Dichlorobenzene................................       14.6-25.4         5.5        17.0-28.8          59-156
1,4-Dichlorobenzene................................       12.6-27.4         7.1        11.8-34.7          18-190
1,1-Dichloroethane.................................       14.5-25.5         5.1        14.2-28.5          59-155
1,2-Dichloroethane.................................       13.6-26.4         6.0        14.3-27.4          49-155
1,1-Dichlorothene..................................       10.1-29.9         9.1         3.7-42.3           D-234
trans-1,2-Dichloroethene...........................       13.9-26.1         5.7        13.6-28.5          54-156

[[Page 199]]

                                                                                                                
1,2-Dichloropropane................................        6.8-33.2        13.8         3.8-36.2           D-210
cis-1,3-Dichloropropene............................        4.8-35.2        15.8         1.0-39.0           D-227
trans-1,3-Dichloropropene..........................       10.0-30.0        10.4         7.6-32.4          17-183
Ethyl benzene......................................       11.8-28.2         7.5        17.4-26.7          37-162
Methylene chloride.................................       12.1-27.9         7.4           D-41.0           D-221
1,1,2,2-Tetrachloroethane..........................       12.1-27.9         7.4        13.5-27.2          46-157
Tetrachloroethene..................................       14.7-25.3         5.0        17.0-26.6          64-148
Toluene............................................       14.9-25.1         4.8        16.6-26.7          47-150
1,1,1-Trichloroethane..............................       15.0-25.0         4.6        13.7-30.1          52-162
1,1,2-Trichloroethane..............................       14.2-25.8         5.5        14.3-27.1          52-150
Trichloroethene....................................       13.3-26.7         6.6        18.6-27.6          71-157
Trichlorofluoromethane.............................        9.6-30.4        10.0         8.9-31.5          17-181
Vinyl chloride.....................................        0.8-39.2        20.0           D-43.5           D-251
----------------------------------------------------------------------------------------------------------------
Q=Concentration measured in QC check sample, in g/L (Section 7.5.3).                                   
s=Standard deviation of four recovery measurements, in g/L (Section 8.2.4).                            
X=Average recovery of four recovery measurements, in g/L (Section 8.2.4).                              
P, Ps=Percent recovery measured, (Section 8.3.2, Section 8.4.2).                                                
D=Detected; result must be greater than zero.                                                                   
aCriteria were calculated assuming a QC check sample concentration of 20 g/L.                          
                                                                                                                
Note: These criteria are based directly upon the method performance data in Table 6. Where necessary, the limits
  for recovery have been broadened to assure applicability of the limits to concentrations below those used to  
  develop Table 6.                                                                                              


                Table 6--Method Accuracy and Precision as Functions of Concentration--Method 624                
----------------------------------------------------------------------------------------------------------------
                                                                      Single analyst                            
               Parameter                 Accuracy, as recovery,   precision, sr (g/L)              m>g/L)              (g/L)    
----------------------------------------------------------------------------------------------------------------
Benzene...............................  0.93C+2.00               0.26X-1.74               0.25X-1.33            
Bromodichloromethane..................  1.03C-1.58               0.15X+0.59               0.20X+1.13            
Bromoform.............................  1.18C-2.35               0.12X+0.36               0.17X+1.38            
Bromomethanea.........................  1.00C                    0.43X                    0.58X                 
Carbon tetrachloride..................  1.10C-1.68               0.12X+0.25               0.11X+0.37            
Chlorobenzene.........................  0.98C+2.28               0.16X-0.09               0.26X-1.92            
Chloroethane..........................  1.18C+0.81               0.14X+2.78               0.29X+1.75            
2-Chloroethylvinyl ether a............  1.00C                    0.62X                    0.84X                 
Chloroform............................  0.93C+0.33               0.16X+0.22               0.18X+0.16            
Chloromethane.........................  1.03C+0.81               0.37X+2.14               0.58X+0.43            
Dibromochloromethane..................  1.01C-0.03               0.17X-0.18               0.17X+0.49            
1,2-Dichlorobenzeneb..................  0.94C+4.47               0.22X-1.45               0.30X-1.20            
1,3-Dichlorobenzene...................  1.06C+1.68               0.14X-0.48               0.18X-0.82            
1,4-Dichlorobenzeneb..................  0.94C+4.47               0.22X-1.45               0.30X-1.20            
1,1-Dichloroethane....................  1.05C+0.36               0.13X-0.05               0.16X+0.47            
1,2-Dichloroethane....................  1.02C+0.45               0.17X-0.32               0.21X-0.38            
1,1-Dichloroethene....................  1.12C+0.61               0.17X+1.06               0.43X-0.22            
trans-1,2,-Dichloroethene.............  1.05C+0.03               0.14X+0.09               0.19X+0.17            
1,2-Dichloropropanea..................  1.00C                    0.33X                    0.45X                 
cis-1,3-Dichloropropenea..............  1.00C                    0.38X                    0.52X                 
trans-1,3-Dichloropropenea............  1.00C                    0.25X                    0.34X                 
Ethyl benzene.........................  0.98C+2.48               0.14X+1.00               0.26X-1.72            
Methylene chloride....................  0.87C+1.88               0.15X+1.07               0.32X+4.00            
1,1,2,2-Tetrachloroethane.............  0.93C+1.76               0.16X+0.69               0.20X+0.41            
Tetrachloroethene.....................  1.06C+0.60               0.13X-0.18               0.16X-0.45            
Toluene...............................  0.98C+2.03               0.15X-0.71               0.22X-1.71            
1,1,1-Trichloroethane.................  1.06C+0.73               0.12X-0.15               0.21X-0.39            
1,1,2-Trichloroethane.................  0.95C+1.71               0.14X+0.02               0.18X+0.00            
Trichloroethene.......................  1.04C+2.27               0.13X+0.36               0.12X+0.59            
Trichloroflouromethane................  0.99C+0.39               0.33X-1.48               0.34X-0.39            
Vinyl chloride........................  1.00C                    0.48X                    0.65X                 
----------------------------------------------------------------------------------------------------------------
X=Expected recovery for one or more measurements of a sample containing a concentration of C, in g/L.  
Sr=Expected single analyst standard deviation of measurements at an average concentration found ofX, in g/L.                                                                                                        
S=Expected interlaboratory standard deviation of measurements at an average concentration found ofX, in g/L.                                                                                                        
C=True value for the concentration, in g/L.                                                            
X=Average recovery found for measurements of samples containing a concentration of C, in g/L.          
a Estimates based upon the performance in a single laboratory.13                                                
b Due to chromatographic resolution problems, performance statements for these isomers are based upon the sums  
  of their concentrations.                                                                                      


[[Page 200]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.038


[[Page 201]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.039


[[Page 202]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.040


[[Page 203]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.041


[[Page 204]]

                   Method 625--Base/Neutrals and Acids

                        1. Scope and Application

    1.1  This method covers the determination of a number of organic 
compounds that are partitioned into an organic solvent and are amenable 
to gas chromatography. The parameters listed in Tables 1 and 2 may be 
qualitatively and quantitatively determined using this method.
    1.2  The method may be extended to include the parameters listed in 
Table 3. Benzidine can be subject to oxidative losses during solvent 
concentration. Under the alkaline conditions of the extraction step, 
-BHC, -BHC, endosulfan I and II, and endrin are 
subject to decomposition. Hexachlorocyclopentadiene is subject to 
thermal decomposition in the inlet of the gas chromatograph, chemical 
reaction in acetone solution, and photochemical decomposition. N-
nitrosodimethylamine is difficult to separate from the solvent under the 
chromatographic conditions described. N-nitrosodiphenylamine decomposes 
in the gas chromatographic inlet and cannot be separated from 
diphenylamine. The preferred method for each of these parameters is 
listed in Table 3.
    1.3  This is a gas chromatographic/mass spectrometry (GC/MS) 
method2, 14 applicable to the determination of the compounds listed 
in Tables 1, 2, and 3 in municipal and industrial discharges as provided 
under 40 CFR 136.1.
    1.4  The method detection limit (MDL, defined in Section 16.1)1 
for each parameter is listed in Tables 4 and 5. The MDL for a specific 
wastewater may differ from those listed, depending upon the nature of 
interferences in the sample matrix.
    1.5  Any modification to this method, beyond those expressly 
permitted, shall be considered as a major modification subject to 
application and approval of alternate test procedures under 40 CFR 136.4 
and 136.5. Depending upon the nature of the modification and the extent 
of intended use, the applicant may be required to demonstrate that the 
modifications will produce equivalent results when applied to relevant 
wastewaters.
    1.6  This method is restricted to use by or under the supervision of 
analysts experienced in the use of a gas chromatograph/mass spectrometer 
and in the interpretation of mass spectra. Each analyst must demonstrate 
the ability to generate acceptable results with this method using the 
procedure described in Section 8.2.

                          2. Summary of Method

    2.1 A measured volume of sample, approximately 1-L, is serially 
extracted with methylene chloride at a pH greater than 11 and again at a 
pH less than 2 using a separatory funnel or a continuous extractor.\2\ 
The methylene chloride extract is dried, concentrated to a volume of 1 
mL, and analyzed by GC/MS. Qualitative identification of the parameters 
in the extract is performed using the retention time and the relative 
abundance of three characteristic masses (m/z). Quantitative analysis is 
performed using internal standard techniques with a single 
characteristic m/z.

                            3. Interferences

    3.1  Method interferences may be caused by contaminants in solvents, 
reagents, glassware, and other sample processing hardware that lead to 
discrete artifacts and/or elevated baselines in the total ion current 
profiles. All of these materials must be routinely demonstrated to be 
free from interferences under the conditions of the analysis by running 
laboratory reagent blanks as described in Section 8.1.3.
    3.1.1  Glassware must be scrupulously cleaned.3 Clean all 
glassware as soon as possible after use by rinsing with the last solvent 
used in it. Solvent rinsing should be followed by detergent washing with 
hot water, and rinses with tap water and distilled water. The glassware 
should then be drained dry, and heated in a muffle furnace at 400  deg.C 
for 15 to 30 min. Some thermally stable materials, such as PCBs, may not 
be eliminated by this treatment. Solvent rinses with acetone and 
pesticide quality hexane may be substituted for the muffle furnace 
heating. Thmrough rinsing with such solvents usually eliminates PCB 
interference. Volumetric ware should not be heated in a muffle furnace. 
After drying and cooling, glassware should be sealed and stored in a 
clean environment to prevent any accumulation of dust or other 
contaminants. Store inverted or capped with aluminum foil.
    3.1.2  The use of high purity reagents and solvents helps to 
minimize interference problems. Purification of solvents by distillation 
in all-glass systems may be required.
    3.2  Matrix interferences may be caused by contaminants that are co-
extracted from the sample. The extent of matrix interferences will vary 
considerably from source to source, depending upon the nature and 
diversity of the industrial complex or municipality being sampled.
    3.3  The base-neutral extraction may cause significantly reduced 
recovery of phenol, 2-methylphenol, and 2,4-dimethylphenol. The analyst 
must recognize that results obtained under these conditions are minimum 
concentrations.
    3.4  The packed gas chromatographic columns recommended for the 
basic fraction may not exhibit sufficient resolution for certain 
isomeric pairs including the following: anthracene and phenanthrene; 
chrysene and benzo(a)anthracene; and benzo(b)fluoranthene and 
benzo(k)fluoranthene. The gas

[[Page 205]]

chromatographic retention time and mass spectra for these pairs of 
compounds are not sufficiently different to make an unambiguous 
identification. Alternative techniques should be used to identify and 
quantify these specific compounds, such as Method 610.
    3.5  In samples that contain an inordinate number of interferences, 
the use of chemical ionization (CI) mass spectrometry may make 
identification easier. Tables 6 and 7 give characteristic CI ions for 
most of the compounds covered by this method. The use of CI mass 
spectrometry to support electron ionization (EI) mass spectrometry is 
encouraged but not required.

                                4. Safety

    4.1  The toxicity or carcinogenicity of each reagent used in this 
method have not been precisely defined; however, each chemical compound 
should be treated as a potential health hazard. From this viewpoint, 
exposure to these chemicals must be reduced to the lowest possible level 
by whatever means available. The laboratory is responsible for 
maintaining a current awareness file of OSHA regulations regarding the 
safe handling of the chemicals specified in this method. A reference 
file of material data handling sheets should also be made available to 
all personnel involved in the chemical analysis. Additional references 
to laboratory safety are available and have been identified4-6 for 
the information of the analyst.
    4.2  The following parameters covered by this method have been 
tentatively classified as known or suspected, human or mammalian 
carcinogens: benzo(a)anthracene, benzidine, 3,3'-dichlorobenzidine, 
benzo(a)pyrene, -BHC, -BHC, -BHC, -
BHC, dibenzo(a,h)anthracene, N-nitrosodimethylamine, 4,4'-DDT, and 
polychlorinated biphenyls (PCBs). Primary standards of these toxic 
compounds should be prepared in a hood. A NIOSH/MESA approved toxic gas 
respirator should be worn when the analyst handles high concentrations 
of these toxic compounds.

                       5. Apparatus and Materials

    5.1  Sampling equipment, for discrete or composit sampling.
    5.1.1  Grab sample bottle--1-L or 1-gt, amber glass, fitted with a 
screw cap lined with Teflon. Foil may be substituted for Teflon if the 
sample is not corrosive. If amber bottles are not available, protect 
samples from light. The bottle and cap liner must be washed, rinsed with 
acetone or methylene chloride, and dried before use to minimize 
contamination.
    5.1.2  Automatic sampler (optional)--The sampler must incorporate 
glass sample containers for the collection of a minimum of 250 mL of 
sample. Sample containers must be kept refrigerated at 4  deg.C and 
protected from light during compositing. If the sampler uses a 
peristaltic pump, a minimum length of compressible silicone rubber 
tubing may be used. before use, however, the compressible tubing should 
be throughly rinsed with methanol, followed by repeated rinsings with 
distilled water to minimize the potential for contamination of the 
sample. An integrating flow meter is required to collect flow 
proportional composites.
    5.2  Glassware (All specifications are suggested. Catalog numbers 
are included for illustration only.):
    5.2.1  Separatory funnel--2-L, with Teflon stopcock.
    5.2.2  Drying column--Chromatographic column, 19 mm ID, with coarse 
frit
    5.2.3  Concentrator tube, Kuderna-Danish--10-mL, graduated (Kontes 
K-570050-1025 or equivalent). Calibration must be checked at the volumes 
employed in the test. Ground glass stopper is used to prevent 
evaporation of extracts.
    5.2.4  Evaporative flask, Kuderna-Danish--500-mL (Kontes K-57001-
0500 or equivalent). Attach to concentrator tube with springs.
    5.2.5  Snyder column, Kuderna-Danish--Three all macro (Kontes K-
503000-0121 or equivalent).
    5.2.6  Snyder column, Kuderna-Danish--Two-ball macro (Kontes K-
569001-0219 or equivalent).
    5.2.7  Vials--10 to 15-mL, amber glass, with Teflon-lined screw cap.
    5.2.8  Continuous liquid--liquid extractor--Equipped with Teflon or 
glass connecting joints and stopcocks requiring no lubrication. 
(Hershberg-Wolf Extractor, Ace Glass Company, Vineland, N.J., P/N 6841-
10 or equivalent.)
    5.3  Boiling chips--Approximately 10/40 mesh. Heat to 400  deg.C for 
30 min of Soxhlet extract with methylene chloride.
    5.4  Water bath--Heated, with concentric ring cover, capable of 
temperature control (2 deg.C). The bath should be used in a 
hood.
    5.5  Balance--Analytical, capable of accurately weighing 0.0001 g.
    5.6  GC/MS system:
    5.6.1  Gas Chromatograph--An analytical system complete with a 
temperature programmable gas chromatograph and all required accessores 
including syringes, analytical columns, and gases. The injection port 
must be designed for on-column injection when using packed columns and 
for splitless injection when using capillary columns.
    5.6.2  Column for base/neutrals--1.8 m long x 2 mm ID glass, packed 
with 3% SP-2250 on Supelcoport (100/120 mesh) or equivalent. This column 
was used to develop the method performance statements in Section 16. 
Guidelines for the use of alternate column packings are provided in 
Section 13.1.
    5.6.3  Column for acids--1.8 m long x 2 mm ID glass, packed with 1% 
SP-1240DA on Supelcoport (100/120 mesh) or equivalent.

[[Page 206]]

This column was used to develop the method performance statements in 
Section 16. Guidelines for the use of alternate column packings are 
given in Section 13.1.
    5.6.4  Mass spectrometer--Capable of scanning from 35 to 450 amu 
every 7 s or less, utilizing a 70 V (nominal) electron energy in the 
electron impact ionization mode, and producing a mass spectrum which 
meets all the criteria in Table 9 when 50 ng of decafluorotriphenyl 
phosphine (DFTPP; bis(perfluorophenyl) phenyl phosphine) is injected 
through the GC inlet.
    5.6.5  GC/MS interface--Any GC to MS interface that gives acceptable 
calibration points at 50 ng per injection for each of the parameters of 
interest and achieves all acceptable performance criteria (Section 12) 
may be used. GC to MS interfaces constructed of all glass or glass-lined 
materials are recommended. Glass can be deactivated by silanizing with 
dichlorodimethylsilane.
    5.6.6  Data system--A computer system must be interfaced to the mass 
spectrometer that allows the contiluous acquisition and storage on 
machine-readable media of all mass spectra obtained throughout the 
duration of the chromatographic program. The computer must have software 
that allows searching any GC/MS data file for specific m/z and plotting 
such m/z abundances versus time or scan number. This type of plot is 
defined as an Extracted Ion Current Profile (EICP). Software must also 
be available that allows integrating the abundance in any EICP between 
specified time or scan number limits.

                               6. Reagents

    6.1  Reagent water--Reagent water is defined as a water in which an 
interferent is not observed at the MDL of the parameters of interest.
    6.2  Sodium hydroxide solution (10 N)--Dissolve 40 g of NaOH (ACS) 
in reagent water and dilute to 100 mL.
    6.3  Sodium thiosulfate--(ACS) Granular.
    6.4  Sulfuric acid (1+1)--Slowly, add 50 mL of H2SO4 (ACS, 
sp. gr. 1.84) to 50 mL of reagent water.
    6.5  Acetone, methanol, methlylene chloride--Pesticide quality or 
equivalent.
    6.6  Sodium sulfate--(ACS) Granular, anhydrous. Purify by heating at 
400  deg.C for 4 h in a shallow tray.
    6.7  Stock standard solutions (1.00 g/L)--standard 
solutions can be prepared from pure standard materials or purchased as 
certified solutions.
    6.7.1  Prepare stock standard solutions by accurately weighing about 
0.0100 g of pure material. Dissolve the material in pesticide quality 
acetone or other suitable solvent and dilute to volume in a 10-mL 
volumetric flask. Larger volumes can be used at the convenience of the 
analyst. When compound purity is assayed to be 96% or greater, the 
weight may be used without correction to calculate the concentration of 
the stock standard. Commercially prepared stock standards may be used at 
any concentration if they are certified by the manufacturer or by an 
independent source.
    6.7.2  Transfer the stock standard solutions into Teflon-sealed 
screw-cap bottles. Store at 4  deg.C and protect from light. Stock 
standard solutions should be checked frequently for signs of degradation 
or evaporation, especially just prior to preparing calibration standards 
from them.
    6.7.3  Stock standard solutions must be replaced after six months, 
or sooner if comparison with quality control check samples indicate a 
problem.
    6.8  Surrogate standard spiking solution--Select a minimum of three 
surrogate compounds from Table 8. Prepare a surrogate standard spiking 
solution containing each selected surrogate compound at a concentration 
of 100 g/mL in acetone. Addition of 1.00 mL of this solution to 
1000 mL of sample is equivalent to a concentration of 100 g/L 
of each surrogate standard. Store the spiking solution at 4  deg.C in 
Teflon-sealed glass container. The solution should be checked frequently 
for stability. The solution must be replaced after six months, or sooner 
if comparison with quality control check standards indicates a problem.
    6.9  DFTPP standard--Prepare a 25 g/mL solution of DFTPP in 
acetone.
    6.10  Quality control check sample concentrate--See Section 8.2.1.

                             7. Calibration

    7.1  Establish gas chromatographic operating parameters equivalent 
to those indicated in Table 4 or 5.
    7.2  Internal standard calibration procedure--To use this approach, 
the analyst must select three or more internal standards that are 
similar in analytical behavior to the compounds of interest. The analyst 
must further demonstrate that the measurement of the internal standards 
is not affected by method or matrix interferences. Some recommended 
internal standards are listed in Table 8. Use the base peak m/z as the 
primary m/z for quantification of the standards. If interferences are 
noted, use one of the next two most intense m/z quantities for 
quantification.
    7.2.1  Prepare calibration standards at a minimum of three 
concentration levels for each parameter of interest by adding 
appropriate volumes of one or more stock standards to a volumetric 
flask. To each calibration standard or standard mixture, add a known 
constant amount of one or more internal standards, and and dilute to 
volume with acetone. One of the calibration standards should be at a 
concentration near, but above, the MDL and the other concentrations 
should correspond to the expected

[[Page 207]]

range of concentrations found in real samples or should define the 
working range of the GC/MS system.
    7.2.2  Using injections of 2 to 5 L, analyze each 
calibration standard according to Section 13 and tabulate the area of 
the primary characteristic m/z (Tables 4 and 5) against concentration 
for each compound and internal standard. Calculate response factors (RF) 
for each compound using Equation 1.

                                                                        
                                         (As)(Cis)                      
                                  RF=  ------------                     
                                         (Ais)(Cs)                      
                                                                        

                                                              Equation 1
where:
    As=Area of the characteristic m/z for the parameter to be 
measured.
    Ais=Area of the characteristic m/z for the internal standard.
    Cis=Concentration of the internal standard (g/L).
    Cs=Concentration of the parameter to be measured (g/
L).

If the RF value over the working range is a constant (<35% RSD), the RF 
can be assumed to be invariant and the average RF can be used for 
calculations. Alternatively, the results can be used to plot a 
calibration curve of response ratios, As/Ais, vs. RF.
    7.3  The working calibration curve or RF must be verified on each 
working day by the measurement of one or more calibration standards. If 
the response for any parameter varies from the predicted response by 
more than 20%, the test must be repeated uning a fresh 
calibration standard. Alternatively, a new calibration curve must be 
prepared for that compound.

                           8. Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality control program. The minimum requirements of this program 
consist of an initial demonstration of laboratory capability and an 
ongoing analysis of spiked samples to evaluate and document data 
quality. The laboratory must maintain records to document the quality of 
data that is generated. Ongoing data quality checks are compared with 
established performance criteria to determine if the results of analyses 
meet the performance characteristics of the method. When results of 
sample spikes indicate atypical method performance, a quality control 
check standard must be analyzed to confirm that the measurements were 
performed in an in-control mode of operation.
    8.1.1  The analyst must make an initial, one-time, demonstration of 
the ability to generate acceptable accuracy and precision with this 
method. This ability is established as described in Section 8.2.
    8.1.2  In recognition of advances that are occuring in 
chromatography, the analyst is permitted certain options (detailed in 
Sections 10.6 and 13.1) to improve the separations or lower the cost of 
measurements. Each time such a modification is made to the method, the 
analyst is required to repeat the procedure in Section 8.2.
    8.1.3  Before processing any samples, the analyst must analyze a 
reagent water blank to demonstrate that interferences from the 
analytical system and glassware are under control. Each time a set of 
samples is extracted or reagents are changed, a reagent water blank must 
be processed as a safeguard against laboratory contamination.
    8.1.4  The laboratory must, on an ongoing basis, spike and analyze a 
minimum of 5% of all samples to monitor and evaluate laboratory data 
quality. This procedure is described in Section 8.3.
    8.1.5  The laboratory must, on an ongoing basis, demonstrate through 
the analyses of quality control check standards that the operation of 
the measurement system is in control. This procedure is described in 
Section 8.4. The frequency of the check standard analyses is equivalent 
to 5% of all samples analyzed but may be reduced if spike recoveries 
from samples (Section 8.3) meet all specified quality control criteria.
    8.1.6  The laboratory must maintain performance records to document 
the quality of data that is generated. This procedure is described in 
Section 8.5.
    8.2  To establish the ability to generate acceptable accuracy and 
precision, the analyst must perform the following operations.
    8.2.1  A quality control (QC) check sample concentrate is required 
containing each parameter of interest at a concentration of 100 
g/mL in acetone. Multiple solutions may be required. PCBs and 
multicomponent pesticides may be omitted from this test. The QC check 
sample concentrate must be obtained from the U.S. Environmental 
Protection Agency, Environmental Monitoring and Support Laboratory in 
Cincinnati, Ohio, if available. If not available from that source, the 
QC check sample concentrate must be obtained from another external 
source. If not available from either source above, the QC check sample 
concentrate must be prepared by the laboratory using stock standards 
prepared independently from those used for calibration.
    8.2.2  Using a pipet, prepare QC check samples at a concentration of 
100 g/L by adding 1.00 mL of QC check sample concentrate to 
each of four 1-L aliquots of reagent water.
    8.2.3  Analyze the well-mixed QC check samples according to the 
method beginning in Section 10 or 11.
    8.2.4  Calculate the average recovery (X) in g/L, and the 
standard deviation of the recovery (s) in g/L, for each 
parameter using the four results.

[[Page 208]]

    8.2.5  For each parameter compare s and X with the corresponding 
acceptance criteria for precision and accuracy, respectively, found in 
Table 6. If s and X for all parameters of interest meet the acceptance 
criteria, the system performance is acceptable and analysis of actual 
samples can begin. If any individual s exceeds the precision limit or 
any individual X falls outside the range for accuracy, the system 
performance is unacceptable for that parameter.

    Note: The large number of parameters in Table 6 present a 
substantial probability that one or more will fail at least one of the 
acceptance criteria when all parameters are analyzed.

    8.2.6  When one or more of the parameters tested fail at least one 
of the acceptance criteria, the analyst must proceed according to 
Section 8.2.6.1 or 8.2.6.2.
    8.2.6.1  Locate and correct the source of the problem and repeat the 
test for all parameters of interest beginning with Section 8.2.2.
    8.2.6.2  Beginning with Section 8.2.2, repeat the test only for 
those parameters that failed to meet criteria. Repeated failure, 
however, will confirm a general problem with the measurement system. If 
this occurs, locate and correct the source of the problem and repeat the 
test for all compounds of interest beginning with Section 8.2.2.
    8.3  The laboratory must, on an ongoing basis, spike at least 5% of 
the samples from each sample site being monitored to assess accuracy. 
For laboratories analyzing 1 to 20 samples per month, at least one 
spiked sample per month is required.
    8.3.1.  The concentration of the spike in the sample should be 
determined as follows:
    8.3.1  If, as in compliance monitoring, the concentration of a 
specific parameter in the sample is being checked against a regulatory 
concentration limit, the spike should be at that limit or 1 to 5 times 
higher than the background concentration determined in Section 8.3.2, 
whichever concentration would be larger.
    8.3.1.2  If the concentration of a specific parameter in the sample 
is not being checked against a limit specific to that parameter, the 
spike should be at 100 g/L or 1 to 5 times higher than the 
background concentration determined in Section 8.3.2, whichever 
concentration would be larger.
    8.3.1.3  If it is impractical to determine background levels before 
spiking (e.g., maximum holding times will be exceeded), the spike 
concentration should be (1) the regulatory concentration limit, if any; 
or, if none (2) the larger of either 5 times higher than the expected 
background concentration or 100 g/L.
    8.3.2  Analyze one sample aliquot to determine the background 
concentration (B) of each parameter. If necessary, prepare a new QC 
check sample concentrate (Section 8.2.1) appropriate for the background 
concentrations in the sample. Spike a second sample aliquot with 1.0 mL 
of the QC check sample concentrate and analyze it to determine the 
concentration after spiking (A) of each parameter. Calculate each 
percent recovery (P) as 100(A-B)%/T, where T is the known true value of 
the spike.
    8.3.3  Compare the percent recovery (P) for each parameter with the 
corresponding QC acceptance criteria found in Table 6. These acceptance 
criteria were calculated to include an allowance for error in 
measurement of both the background and spike concentrations, assuming a 
spike to background ratio of 5:1. This error will be accounted for to 
the extent that the analyst's spike to background ratio approaches 
5:1.7 If spiking was performed at a concentration lower than 100 
g/L, the analyst must use either the QC acceptance criteria in 
Table 6, or optional QC acceptance criteria calculated for the specific 
spike concentration. To calculate optional acceptance criteria for the 
recovery of a parameter: (1) Calculate accuracy (X') using the equation 
in Table 7, substituting the spike concentration (T) for C; (2) 
calculate overall precision (S') using the equation in Table 7, 
substituting X' for X; (3) calculate the range for recovery at the spike 
concentration as (100 X'/T)2.44(100 S'/T)%7
    8.3.4  If any individual P falls outside the designated range for 
recovery, that parameter has failed the acceptance criteria. A check 
standard containing each parameter that failed the criteria must be 
analyzed as described in Section 8.4.
    8.4  If any parameter fails the acceptance criteria for recovery in 
Section 8.3, a QC check standard containing each parameter that failed 
must be prepared and analyzed.

    Note: The frequency for the required analysis of a QC check standard 
will depend upon the number of parameters being simultaneously tested, 
the complexity of the sample matrix, and the performance of the 
laboratory. If the entire list of single-component parameters in Table 6 
must be measured in the sample in Section 8.3, the probability that the 
analysis of a QC check standard will be required is high. In this case 
the QC check standard should be routinely analyzed with the spike 
sample.

    8.4.1  Prepare the QC check standard by adding 1.0 mL of QC check 
sample concentrate (Section 8.2.1 or 8.3.2) to 1 L of reagent water. The 
QC check standard needs only to contain the parameters that failed 
criteria in the test in Section 8.3.
    8.4.2  Analyze the QC check standard to determine the concentration 
measured (A) of each parameter. Calculate each percent recovery 
(PS) as 100 (A/T)%, where T is the true value of the standard 
concentration.

[[Page 209]]

    8.4.3  Compare the percent recovery (Ps) for each parameter 
with the corresponding QC acceptance criteria found in Table 6. Only 
parameters that failed the test in Section 8.3 need to be compared with 
these criteria. If the recovery of any such parameter falls outside the 
designated range, the laboratory performance for that parameter is 
judged to be out of control, and the problem must be immediately 
identified and corrected. The analytical result for that parameter in 
the unspiked sample is suspect and may not be reported for regulatory 
compliance purposes.
    8.5  As part of the QC program for the laboratory, method accuracy 
for wastewater samples must be assessed and records must be maintained. 
After the analysis of five spiked wastewater samples as in Section 8.3, 
calculate the average percent recovery (P) and the standard deviation of 
the percent recovery (sp). Express the accuracy assessment as a 
percent interval from P-2sp to P+2sp. If P=90% and 
sp=10%, for example, the accuracy interval is expressed as 70-110%. 
Update the accuracy assessment for each parameter on a regular basis 
(e.g. after each five to ten new accuracy measurements).
    8.6  As a quality control check, the laboratory must spike all 
samples with the surrogate standard spiking solution as described in 
Section 10.2, and calculate the percent recovery of each surrogate 
compound.
    8.7  It is recommended that the laboratory adopt additional quality 
assurance practices for use with this method. The specific practices 
that are most productive depend upon the needs of the laboratory and the 
nature of the samples. Field duplicates may be analyzed to assess the 
precision of the environmental measurements. Whenever possible, the 
laboratory should analyze standard reference materials and participate 
in relevant performance evaluation studies.

            9. Sample Collection, Preservation, and Handling

    9.1  Grab samples must be collected in glass containers. 
Conventional sampling practices8 should be followed, except that 
the bottle must not be prerinsed with sample before collection. 
Composite samples should be collected in refrigerated glass containers 
in accordance with the requirements of the program. Automatic sampling 
equipment must be as free as possible of Tygon tubing and other 
potential sources of contamination.
    9.2  All sampling must be iced or refrigerated at 4  deg.C from the 
time of collection until extraction. Fill the sample bottles and, if 
residual chlorine is present, add 80 mg of sodium thiosulfate per liter 
of sample and mix well. EPA Methods 330.4 and 330.5 may be used for 
measurement of residual chlorine.9 Field test kits are available 
for this purpose.
    9.3  All samples must be extracted within 7 days of collection and 
completely analyzed within 40 days of extraction.

                    10. Separatory Funnel Extraction

    10.1  Samples are usually extracted using separatory funnel 
techniques. If emulsions will prevent achieving acceptable solvent 
recovery with separatory funnel extractions, continuous extraction 
(Section 11) may be used. The separatory funnel extraction scheme 
described below assumes a sample volume of 1 L. When sample volumes of 2 
L are to be extracted, use 250, 100, and 100-mL volumes of methylene 
chloride for the serial extraction of the base/neutrals and 200, 100, 
and 100-mL volumes of methylene chloride for the acids.
    10.2  Mark the water meniscus on the side of the sample bottle for 
later determination of sample volume. Pour the entire sample into a 2-L 
separatory funnel. Pipet 1.00 mL of the surrogate standard spiking 
solution into the separatory funnel and mix well. Check the pH of the 
sample with wide-range pH paper and adjust to pH>11 with sodium 
hydroxide solution.
    10.3  Add 60 mL of methylene chloride to the sample bottle, seal, 
and shake for 30 s to rinse the inner surface. Transfer the solvent to 
the separatory funnel and extract the sample by shaking the funnel for 2 
min. with periodic venting to release excess pressure. Allow the organic 
layer to separate from the water phase for a minimum of 10 min. If the 
emulsion interface between layers is more than one-third the volume of 
the solvent layer, the analyst must employ mechanical techniques to 
complete the phase separation. The optimum technique depends upon the 
sample, but may include stirring, filtration of the emulsion through 
glass wool, centrifugation, or other physical methods. Collect the 
methylene chloride extract in a 250-mL Erlenmeyer flask. If the emulsion 
cannot be broken (recovery of less than 80% of the methylene chloride, 
corrected for the water solubility of methylene chloride), transfer the 
sample, solvent, and emulsion into the extraction chamber of a 
continuous extractor and proceed as described in Section 11.3.
    10.4  Add a second 60-mL volume of methylene chloride to the sample 
bottle and repeat the extraction procedure a second time, combining the 
extracts in the Erlenmeyer flask. Perform a third extraction in the same 
manner. Label the combined extract as the base/neutral fraction.
    10.5  Adjust the pH of the aqueous phase to less than 2 using 
sulfuric acid. Serially extract the acidified aqueous phase three times 
with 60-mL aliquots of methylene chloride. Collect and combine the 
extracts in a 250-mL Erlenmeyer flask and label the combined extracts as 
the acid fraction.

[[Page 210]]

    10.6  For each fraction, assemble a Kuderna-Danish (K-D) 
concentrator by attaching a 10-mL concentrator tube to a 500-mL 
evaporative flask. Other concentration devices or techniques may be used 
in place of the K-D concentrator if the requirements of Section 8.2 are 
met.
    10.7  For each fraction, pour the combined extract through a 
solvent-rinsed drying column containing about 10 cm of anhydrous sodium 
sulfate, and collect the extract in the K-D concentrator. Rinse the 
Erlenmeyer flask and column with 20 to 30 mL of methylene chloride to 
complete the quantitative transfer.
    10.8  Add one or two clean boiling chips and attach a three-ball 
Snyder column to the evaporative flask for each fraction. Prewet each 
Snyder column by adding about 1 mL of methylene chloride to the top. 
Place the K-D apparatus on a hot water bath (60 to 65  deg.C) so that 
the concentrator tube is partially immersed in the hot water, and the 
entire lower rounded surface of the flask is bathed with hot vapor. 
Adjust the vertical position of the apparatus and the water temperature 
as required to complete the concentration in 15 to 20 min. At the proper 
rate of distillation the balls of the column will actively chatter but 
the chambers will not flood with condensed solvent. When the apparent 
volume of liquid reaches 1 mL, remove the K-D apparatus from the water 
bath and allow it to drain and cool for at least 10 min. Remove the 
Snyder column and rinse the flask and its lower joint into the 
concentrator tube with 1 to 2 mL of methylene chloride. A 5-mL syringe 
is recommended for this operation.
    10.9  Add another one or two clean boiling chips to the concentrator 
tube for each fraction and attach a two-ball micro-Snyder column. Prewet 
the Snyder column by adding about 0.5 mL of methylene chloride to the 
top. Place the K-D apparatus on a hot water bath (60 to 65  deg.C) so 
that the concentrator tube is partially immersed in hot water. Adjust 
the vertical position of the apparatus and the water temperature as 
required to complete the concentration in 5 to 10 min. At the proper 
rate of distillation the balls of the column will actively chatter but 
the chambers will not flood with condensed solvent. When the apparent 
volume of liquid reaches about 0.5 mL, remove the K-D apparatus from the 
water bath and allow it to drain and cool for at least 10 min. Remove 
the Snyder column and rinse the flask and its lower joint into the 
concentrator tube with approximately 0.2 mL of acetone or methylene 
chloride. Adjust the final volume to 1.0 mL with the solvent. Stopper 
the concentrator tube and store refrigerated if further processing will 
not be performed immediately. If the extracts will be stored longer than 
two days, they should be transferred to Teflon-sealed screw-cap vials 
and labeled base/neutral or acid fraction as appropriate.
    10.10  Determine the original sample volume by refilling the sample 
bottle to the mark and transferring the liquid to a 1000-mL graduated 
cylinder. Record the sample volume to the nearest 5 mL.

                        11. Continuous Extraction

    11.1  When experience with a sample from a given source indicates 
that a serious emulsion problem will result or an emulsion is 
encountered using a separatory funnel in Section 10.3, a continuous 
extractor should be used.
    11.2  Mark the water meniscus on the side of the sample bottle for 
later determination of sample volume. Check the pH of the sample with 
wide-range pH paper and adjust to pH >11 with sodium hydroxide solution. 
Transfer the sample to the continuous extractor and using a pipet, add 
1.00 mL of surrogate standard spiking solution and mix well. Add 60 mL 
of methylene chloride to the sample bottle, seal, and shake for 30 s to 
rinse the inner surface. Transfer the solvent to the extractor.
    11.3  Repeat the sample bottle rinse with an additional 50 to 100-mL 
portion of methylene chloride and add the rinse to the extractor.
    11.4  Add 200 to 500 mL of methylene chloride to the distilling 
flask, add sufficient reagent water to ensure proper operation, and 
extract for 24 h. Allow to cool, then detach the distilling flask. Dry, 
concentrate, and seal the extract as in Sections 10.6 through 10.9.
    11.5  Charge a clean distilling flask with 500 mL of methylene 
chloride and attach it to the continuous extractor. Carefully, while 
stirring, adjust the pH of the aqueous phase to less than 2 using 
sulfuric acid. Extract for 24 h. Dry, concentrate, and seal the extract 
as in Sections 10.6 through 10.9.

                    12. Daily GC/MS Performance Tests

    12.1  At the beginning of each day that analyses are to be 
performed, the GC/MS system must be checked to see if acceptable 
performance criteria are achieved for DFTPP.10 Each day that 
benzidine is to be determined, the tailing factor criterion described in 
Section 12.4 must be achieved. Each day that the acids are to be 
determined, the tailing factor criterion in Section 12.5 must be 
achieved.
    12.2  These performance tests require the following instrumental 
parameters:

    Electron Energy: 70 V (nominal)
    Mass Range: 35 to 450 amu
    Scan Time: To give at least 5 scans per peak but not to exceed 7 s 
per scan.

    12.3  DFTPP performance test--At the beginning of each day, inject 2 
L (50 ng) of

[[Page 211]]

DFTPP standard solution. Obtain a background-corrected mass spectra of 
DFTPP and confirm that all the key m/z criteria in Table 9 are achieved. 
If all the criteria are not achieved, the analyst must retune the mass 
spectrometer and repeat the test until all criteria are achieved. The 
performance criteria must be achieved before any samples, blanks, or 
standards are analyzed. The taililg factor tests in Sections 12.4 and 
12.5 may be performed simultaneously with the DFTPP test.
    12.4  Column performance test for base/neutrals--At the beginning of 
each day that the base/neutral fraction is to be analyzed for benzidine, 
the benzidine tailing factor must be calculated. Inject 100 ng of 
benzidine either separately or as a part of a standard mixture that may 
contain DFTPP and calculate the tailing factor. The benzidine tailing 
factor must be less than 3.0. Calculation of the tailing factor is 
illustrated in Figure 13.11 Replace the column packing if the 
tailing factor criterion cannot be achieved.
    12.5  Column performance test for acids--At the beginning of each 
day that the acids are to be determined, inject 50 ng of 
pentachlorophenol either separately or as a part of a standard mix that 
may contain DFTPP. The tailing factor for pentachlorophenol must be less 
than 5. Calculation of the tailing factor is illustrated in Figure 
13.11 Replace the column packing if the tailing factor criterion 
cannot be achieved.

                13. Gas Chromatography/Mass Spectrometry

    13.1  Table 4 summarizes the recommended gas chromatographic 
operating conditions for the base/neutral fraction. Table 5 summarizes 
the recommended gas chromatographic operating conditions for the acid 
fraction. Included in these tables are retention times and MDL that can 
be achieved under these conditions. Examples of the separations achieved 
by these columns are shown in Figures 1 through 12. Other packed or 
capillary (open-tubular) columns or chromatographic conditions may be 
used if the requirements of Section 8.2 are met.
    13.2  After conducting the GC/MS performance tests in Section 12, 
calibrate the system daily as described in Section 7.
    13.3  The internal standard must be added to sample extract and 
mixed thoroughly immediately before it is injected into the instrument. 
This procedure minimizes losses due to adsorption, chemical reaction or 
evaporation.
    13.4  Inject 2 to 5 L of the sample extract or standard 
into the GC/MS system using the solvent-flush technique.12 Smaller 
(1.0 L) volumes may be injected if automatic devices are 
employed. Record the volume injected to the nearest 0.05 L.
    13.5  If the response for any m/z exceeds the working range of the 
GC/MS system, dilute the extract and reanalyze.
    13.6  Perform all qualitative and quantitative measurements as 
described in Sections 14 and 15. When the extracts are not being used 
for analyses, store them refrigerated at 4 deg.C, protected from light 
in screw-cap vials equipped with unpierced Teflon-lined septa.

                     14. Qualitative Identification

    14.1  Obtain EICPs for the primary m/z and the two other masses 
listed in Tables 4 and 5. See Section 7.3 for masses to be used with 
internal and surrogate standards. The following criteria must be met to 
make a qualitative identification:
    14.1.1  The characteristic masses of each parameter of interest must 
maximize in the same or within one scan of each other.
    14.1.2  The retention time must fall within 30 s of the 
retention time of the authentic compound.
    14.1.3  The relative peak heights of the three characteristic masses 
in the EICPs must fall within 20% of the relative 
intensities of these masses in a reference mass spectrum. The reference 
mass spectrum can be obtained from a standard analyzed in the GC/MS 
system or from a reference library.
    14.2  Structural isomers that have very similar mass spectra and 
less than 30 s difference in retention time, can be explicitly 
identified only if the resolution between authentic isomers in a 
standard mix is acceptable. Acceptable resolution is achieved if the 
baseline to valley height between the isomers is less than 25% of the 
sum of the two peak heights. Otherwise, structural isomers are 
identified as isomeric pairs.

                            15. Calculations

    15.1  When a parameter has been identified, the quantitation of that 
parameter will be based on the integrated abundance from the EICP of the 
primary characteristic m/z in Tables 4 and 5. Use the base peak m/z for 
internal and surrogate standards. If the sample produces an interference 
for the primary m/z, use a secondary characteristic m/z to quantitate.
    Calculate the concentration in the sample using the response factor 
(RF) determined in Section 7.2.2 and Equation 3.

                                                                                                                
                                                                               (As)(Is)                         
                                      Concentration (g/L)=      --------------------                   
                                                                             (Ais)(RF)(Vo)                      
                                                                                                                


[[Page 212]]

                                                              Equation 3
where:
    As=Area of the characteristic m/z for the parameter or 
surrogate standard to be measured.
    Ais=Area of the characteristic m/z for the internal standard.
    Is=Amount of internal standard added to each extract 
(g).
    Vo=Volume of water extracted (L).

    15.2  Report results in g/L without correction for recovery 
data. All QC data obtained should be reported with the sample results.

                         16. Method Performance

    16.1  The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the value is above zero.1 The MDL concentrations 
listed in Tables 4 and 5 were obtained using reagent water.13 The 
MDL actually achieved in a given analysis will vary depending on 
instrument sensitivity and matrix effects.
    16.2  This method was tested by 15 laboratories using reagent water, 
drinking water, surface water, and industrial wastewaters spiked at six 
concentrations over the range 5 to 1300 g/L.14 Single 
operator precision, overall precision, and method accuracy were found to 
be directly related to the concentration of the parameter and 
essentially independent of the sample matrix. Linear equations to 
describe these relationships are presented in Table 7.

    17. Screening Procedure for 2,3,7,8-Tetrachlorodibenzo-p-dioxin 
                             (2,3,7,8-TCDD)

    17.1  If the sample must be screened for the presence of 2,3,7,8-
TCDD, it is recommended that the reference material not be handled in 
the laboratory unless extensive safety precautions are employed. It is 
sufficient to analyze the base/neutral extract by selected ion 
monitoring (SIM) GC/MS techniques, as follows:
    17.1.1  Concentrate the base/neutral extract to a final volume of 
0.2 ml.
    17.1.2  Adjust the temperature of the base/neutral column (Section 
5.6.2) to 220  deg.C.
    17.1.3  Operate the mass spectrometer to acquire data in the SIM 
mode using the ions at m/z 257, 320 and 322 and a dwell time no greater 
than 333 milliseconds per mass.
    17.1.4  Inject 5 to 7 L of the base/neutral extract. 
Collect SIM data for a total of 10 min.
    17.1.5  The possible presence of 2,3,7,8-TCDD is indicated if all 
three masses exhibit simultaneous peaks at any point in the selected ion 
current profiles.
    17.1.6  For each occurrence where the possible presence of 2,3,7,8-
TCDD is indicated, calculate and retain the relative abundances of each 
of the three masses.
    17.2  False positives to this test may be caused by the presence of 
single or coeluting combinations of compounds whose mass spectra contain 
all of these masses.
    17.3  Conclusive results of the presence and concentration level of 
2,3,7,8-TCDD can be obtained only from a properly equipped laboratory 
through the use of EPA Method 613 or other approved alternate test 
procedures.

                               References

    1. 40 CFR part 136, appendix B.
    2. ``Sampling and Analysis Procedures for Screening of Industrial 
Effluents for Priority Pollutants,'' U.S. Environmental Protection 
Agency, Environmental Monitoring and Support Laboratory, Cincinnati, 
Ohio 45268, March 1977, Revised April 1977. Available from Effluent 
Guidelines Division, Washington, DC 20460.
    3. ASTM Annual Book of Standards, Part 31, D3694-78. ``Standard 
Practices for Preparation of Sample Containers and for Preservation of 
Organic Constituents,'' American Society for Testing and Materials, 
Philadelphia.
    4. ``Carcinogens--Working With Carcinogens,'' Department of Health, 
Education, and Welfare, Public Health Service, Center for Disease 
Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    5. ``OSHA Safety and Health Standards, General Industry,'' (29 CFR 
part 1910), Occupational Safety and Health Administration, OSHA 2206 
(Revised, January 1976).
    6. ``Safety in Academic Chemistry Laboratories,''American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    7. Provost, L.P., and Elder, R.S. ``Interpretation of Percent 
Recovery Data,'' American Laboratory, 15, 58-63 (1983). (The value 2.44 
used in the equation in Section 8.3.3 is two times the value 1.22 
derived in this report.)
    8. ASTM Annual Book of Standards, Part 31, D3370-76. ``Standard 
Practices for Sampling Water,'' American Society for Testing and 
Materials, Philadelphia.
    9. ``Methods 330.4 (Titrimetric, DPD-FAS) and 330.5 
(Spectrophotometric, DPD) for Chlorine, Total Residual,'' Methods for 
Chemical Analysis of Water and Wastes, EPA-600/4-79-020, U.S. 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory, Cincinnati, Ohio 45268, March 1979.
    10. Eichelberger, J.W., Harris, L.E., and Budde, W.L. ``Reference 
Compound to Calibrate Ion Abundance Measurement in Gas Chromatography-
Mass Spectometry,'' Analytical Chemistry, 47, 995 (1975).
    11. McNair, N.M. and Bonelli, E.J. ``Basic Chromatography,'' 
Consolidated Printing, Berkeley, California, p. 52, 1969.
    12. Burke, J.A. ``Gas Chromatography for Pesticide Residue Analysis; 
Some Practical

[[Page 213]]

Aspects,'' Journal of the Association of Official Analytical Chemists, 
48, 1037 (1965).
    13. Olynyk, P., Budde, W.L., and Eichelberger, J.W. ``Method 
Detection Limit for Methods 624 and 625,'' Unpublished report, May 14, 
1980.
    14. ``EPA Method Study 30, Method 625, Base/Neutrals, Acids, and 
Pesticides,'' EPA 600/4-84-053, National Technical Information Service, 
PB84-206572, Springfield, Virginia 22161, June 1984.

                   Table 1--Base/Neutral Extractables                   
------------------------------------------------------------------------
                                                    STORET              
                    Parameter                         No.      CAS No.  
------------------------------------------------------------------------
Acenaphthene.....................................     34205      83-32-9
Acenaphthylene...................................     34200     208-96-8
Anthracene.......................................     34220     120-12-7
Aldrin...........................................     39330     309-00-2
Benzo(a)anthracene...............................     34526      56-55-3
Benzo(b)fluoranthene.............................     34230     205-99-2
Benzo(k)fluoranthene.............................     34242     207-08-9
Benzo(a)pyrene...................................     34247      50-32-8
Benzo(ghi)perylene...............................     34521     191-24-2
Benzyl butyl phthalate...........................     34292      85-68-7
-BHC....................................     39338     319-85-7
-BHC....................................     34259     319-86-8
Bis(2-chloroethyl) ether.........................     34273     111-44-4
Bis(2-chloroethoxy)methane.......................     34278     111-91-1
Bis(2-ethylhexyl) phthalate......................     39100     117-81-7
Bis(2-chloroisopropyl) ethera....................     34283     108-60-1
4-Bromophenyl phenyl ethera......................     34636     101-55-3
Chlordane........................................     39350      57-74-9
2-Chloronaphthalele..............................     34581      91-58-7
4-Chlorophenyl phenyl ether......................     34641    7005-72-3
Chrysene.........................................     34320     218-01-9
4,4-DDD..........................................     39310      72-54-8
4,4-DDE..........................................     39320      72-55-9
4,4-DDT..........................................     39300      50-29-3
Dibenzo(a,h)anthracene...........................     34556      53-70-3
Di-n-butylphthalate..............................     39110      84-74-2
1,3-Dichlorobenzene..............................     34566     541-73-1
1,2-Dichlorobenzene..............................     34536      95-50-1
1,4-Dichlorobenzene..............................     34571     106-46-7
3,3-Dichlorobenzidine............................     34631      91-94-1
Dieldrin.........................................     39380      60-57-1
Diethyl phthalate................................     34336      84-66-2
Dimethyl phthalate...............................     34341     131-11-3
2,4-Dinitrotoluene...............................     34611     121-14-2
2,6-Dinitrotoluene...............................     34626     606-20-2
Di-n-octylphthalate..............................     34596     117-84-0
Endosulfan sulfate...............................     34351    1031-07-8
Endrin aldehyde..................................     34366    7421-93-4
Fluoranthene.....................................     34376     206-44-0
Fluorene.........................................     34381      86-73-7
Heptachlor.......................................     39410      76-44-8
Heptchlor epoxide................................     39420    1024-57-3
Hexachlorobenzene................................     39700     118-74-1
Hexachlorobutadiene..............................     34391      87-68-3
Hexachloroethane.................................     34396      67-72-1
Indeno(1,2,3-cd)pyrene...........................     34403     193-39-5
Isophorone.......................................     34408      78-59-1
Naphthalene......................................     34696      91-20-3
Nitrobenzene.....................................     34447      98-95-3
N-Nitrosodi-n-propylamine........................     34428     621-64-7
PCB-1016.........................................     34671   12674-11-2
PCB-1221.........................................     39488   11104-28-2
PCB-1232.........................................     39492   11141-16-5
PCB-1242.........................................     39496   53469-21-9
PCB-1248.........................................     39500   12672-29-6
PCB-1254.........................................     39504   11097-69-1
PCB-1260.........................................     39508   11096-82-5
Phenanthrene.....................................     34461      85-01-8
Pyrene...........................................     34469     129-00-0
Toxaphene........................................     39400    8001-35-2
1,2,4-Trichlorobenzene...........................     34551     120-82-1
------------------------------------------------------------------------
a The proper chemical name is 2,2-oxybis(1-chloropropane).              


                       Table 2--Acid Extractables                       
------------------------------------------------------------------------
                                                    STORET              
                    Parameter                         No.      CAS No.  
------------------------------------------------------------------------
4-Chloro-3-methylphenol..........................     34452      59-50-7
2-Chlorophenol...................................     34586      95-57-8
2,4-Dichlorophenol...............................     34601     120-83-2
2,4-Dimethylphenol...............................     34606     105-67-9
2,4-Dinitrophenol................................     34616      51-28-5
2-Methyl-4,6-dinitrophenol.......................     34657     534-52-1
2-Nitrophenol....................................     34591      88-75-5
4-Nitrophenol....................................     34646     100-02-7
Pentachlorophenol................................     39032      87-86-5
Phenol...........................................     34694     108-95-2
2,4,6-Trichlorophenol............................     34621      88-06-2
------------------------------------------------------------------------


             Table 3--Additional Extractable Parameters\\\a             
------------------------------------------------------------------------
                                            STORET                      
                Parameter                     No.      CAS No.    Method
------------------------------------------------------------------------
Benzidine................................     39120      92-87-5     605
-BHC............................     39337     319-84-6     608
-BHC............................     39340      58-89-8     608
Endosulfan I.............................     34361     959-98-8     608
Endosulfan II............................     34356   33213-65-9     608
Endrin...................................     39390      72-20-8     608
Hexachlorocylopentadiene.................     34386      77-47-4     612
N-Nitrosodimethylamine...................     34438      62-75-9     607
N-Nitrosodiphenylamine...................     34433      86-30-6     607
------------------------------------------------------------------------
a See Section 1.2.                                                      


                  Table 4--Chromatographic Conditions, Method Detection Limits, and Characteristic Masses for Base/Neutral Extractables                 
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 Method                         Characteristic masses                   
                                                                   Retention    detection  -------------------------------------------------------------
                            Parameter                                 time        limit             Electron impact              Chemical ionization    
                                                                     (min)    (g/ -------------------------------------------------------------
                                                                                   L)        Primary  Secondary  Secondary   Methane   Methane   Methane
--------------------------------------------------------------------------------------------------------------------------------------------------------
1,3-Dichlorobenzene..............................................        7.4         1.9         146        148        113       146       148       150
1,4-Dichlorobenzene..............................................        7.8         4.4         146        148        113       146       148       150
Hexachloroethane.................................................        8.4         1.6         117        201        199       199       201       203

[[Page 214]]

                                                                                                                                                        
Bis(2-chloroethyl) ethera........................................        8.4         5.7          93         63         95        63       107       109
1,2-Dichlorobenzene..............................................        8.4         1.9         146        148        113       146       148       150
Bis(2-chloroisopropyl) ethera....................................        9.3         5.7          45         77         79        77       135       137
N-Nitrosodi-n-propylamine........................................  .........  ............       130         42        101  ........  ........  ........
Nitrobenzene.....................................................       11.1         1.9          77        123         65       124       152       164
Hexachlorobutadiene..............................................       11.4         0.9         225        223        227       223       225       227
1,2,4-Trichlorobenzene...........................................       11.6         1.9         180        182        145       181       183       209
Isophorone.......................................................       11.9         2.2          82         95        138       139       167       178
Naphthalene......................................................       12.1         1.6         128        129        127       129       157       169
Bis(2-chloroethoxy) methane......................................       12.2         5.3          93         95        123        65       107       137
Hexachlorocyclopentadienea.......................................       13.9  ............       237        235        272       235       237       239
2-Chloronaphthalene..............................................       15.9         1.9         162        164        127       163       191       203
Acenaphthylene...................................................       17.4         3.5         152        151        153       152       153       181
Acenaphthene.....................................................       17.8         1.9         154        153        152       154       155       183
Dimethyl phthalate...............................................       18.3         1.6         163        194        164       151       163       164
2,6-Dinitrotoluene...............................................       18.7         1.9         165         89        121       183       211       223
Fluorene.........................................................       19.5         1.9         166        165        167       166       167       195
4-Chlorophenyl phenyl ether......................................       19.5         4.2         204        206        141  ........  ........  ........
2,4-Dinitrotoluene...............................................       19.8         5.7         165         63        182       183       211       223
Diethyl phthalate................................................       20.1         1.9         149        177        150       177       223       251
N-Nitrosodiphenylamineb..........................................       20.5         1.9         169        168        167       169       170       198
Hexachlorobenzene................................................       21.0         1.9         284        142        249       284       286       288
-BHCb...................................................       21.1  ............       183        181        109  ........  ........  ........
4-Bromophenyl phenyl ether.......................................       21.2         1.9         248        250        141       249       251       277
-BHCb...................................................       22.4  ............       183        181        109  ........  ........  ........
Phenanthrene.....................................................       22.8         5.4         178        179        176       178       179       207
Anthracene.......................................................       22.8         1.9         178        179        176       178       179       207
-BHC....................................................       23.4         4.2         181        183        109  ........  ........  ........
Heptachlor.......................................................       23.4         1.9         100        272        274  ........  ........  ........
-BHC....................................................       23.7         3.1         183        109        181  ........  ........  ........
Aldrin...........................................................       24.0         1.9          66        263        220  ........  ........  ........
Dibutyl phthalate................................................       24.7         2.5         149        150        104       149       205       279
Heptachlor epoxide...............................................       25.6         2.2         353        355        351  ........  ........  ........
Endosulfan Ib....................................................       26.4  ............       237        339        341  ........  ........  ........
Fluoranthene.....................................................       26.5         2.2         202        101        100       203       231       243
Dieldrin.........................................................       27.2         2.5          79        263        279  ........  ........  ........
4,4-DDE..........................................................       27.2         5.6         246        248        176  ........  ........  ........
Pyrene...........................................................       27.3         1.9         202        101        100       203       231       243
Endrinb..........................................................       27.9  ............        81        263         82  ........  ........  ........
Endosulfan IIb...................................................       28.6  ............       237        339        341  ........  ........  ........
4,4-DDD..........................................................       28.6         2.8         235        237        165  ........  ........  ........
Benzidineb.......................................................       28.8          44         184         92        185       185       213       225
4,4-DDT..........................................................       29.3         4.7         235        237        165  ........  ........  ........
Endosulfan sulfate...............................................       29.8         5.6         272        387        422  ........  ........  ........
Endrin aldehyde..................................................  .........  ............        67        345        250  ........  ........  ........
Butyl benzyl phthalate...........................................       29.9         2.5         149         91        206       149       299       327
Bis(2-ethylhexyl) phthalate......................................       30.6         2.5         149        167        279       149  ........  ........
Chrysene.........................................................       31.5         2.5         228        226        229       228       229       257
Benzo(a)anthracene...............................................       31.5         7.8         228        229        226       228       229       257
3,3-Dichlorobenzidine............................................       32.2        16.5         252        254        126  ........  ........  ........
Di-n-octyl phthalate.............................................       32.5         2.5         149  .........  .........  ........  ........  ........
Benzo(b)fluoranthene.............................................       34.9         4.8         252        253        125       252       253       281
Benzo(k)fluoranthene.............................................       34.9         2.5         252        253        125       252       253       281
Benzo(a)pyrene...................................................       36.4         2.5         252        253        125       252       253       281
Indeno(1,2,3-cd) pyrene..........................................       42.7         3.7         276        138        277       276       277       305
Dibenzo(a,h)anthracene...........................................       43.2         2.5         278        139        279       278       279       307
Benzo(ghi)perylene...............................................       45.1         4.1         276        138        277       276       277       305
N-Nitrosodimethylamineb..........................................  .........  ............        42         74         44  ........  ........  ........
Chlordanec.......................................................      19-30  ............       373        375        377  ........  ........  ........
Toxaphenec.......................................................      25-34  ............       159        231        233  ........  ........  ........
PCB 1016c........................................................      18-30  ............       224        260        294  ........  ........  ........
PCB 1221c........................................................      15-30          30         190        224        260  ........  ........  ........
PCB 1232c........................................................      15-32  ............       190        224        260  ........  ........  ........
PCB 1242c........................................................      15-32  ............       224        260        294  ........  ........  ........
PCB 1248c........................................................      12-34  ............       294        330        262  ........  ........  ........
PCB 1254c........................................................      22-34          36         294        330        362  ........  ........  ........

[[Page 215]]

                                                                                                                                                        
PCB 1260c........................................................      23-32  ............       330        362        394  ........  ........  ........
--------------------------------------------------------------------------------------------------------------------------------------------------------
a The proper chemical name is 2,2-bisoxy(1-chloropropane).                                                                                              
b See Section 1.2.                                                                                                                                      
c These compounds are mixtures of various isomers (See Figures 2 through 12). Column conditions: Supelcoport (100/120 mesh) coated with 3% SP-2250      
  packed in a 1.8 m long x 2 mm ID glass column with helium carrier gas at 30 mL/min. flow rate. Column temperature held isothermal at 50 oC for 4 min.,
  then programmed at 8 oC/min. to 270 oC and held for 30 min.                                                                                           


                      Table 5--Chromatographic Conditions, Method Detection Limits, and Characteristic Masses for Acid Extractables                     
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 Method                         Characteristic masses                   
                                                                   Retention    detection  -------------------------------------------------------------
                            Parameter                                 time        limit             Electron Impact              Chemical ionization    
                                                                     (min)    (g/ -------------------------------------------------------------
                                                                                   L)        Primary  Secondary  Secondary   Methane   Methane   Methane
--------------------------------------------------------------------------------------------------------------------------------------------------------
2-Chlorophenol...................................................        5.9         3.3         128         64        130       129       131       157
2-Nitrophenol....................................................        6.5         3.6         139         65        109       140       168       122
Phenol...........................................................        8.0         1.5          94         65         66        95       123       135
2,4-Dimethylphenol...............................................        9.4         2.7         122        107        121       123       151       163
2,4-Dichlorophenol...............................................        9.8         2.7         162        164         98       163       165       167
2,4,6-Trichlorophenol............................................       11.8         2.7         196        198        200       197       199       201
4-Chloro-3-methylphenol..........................................       13.2         3.0         142        107        144       143       171       183
2,4-Dinitrophenol................................................       15.9          42         184         63        154       185       213       225
2-Methyl-4,6-dinitrophenol.......................................       16.2          24         198        182         77       199       227       239
Pentachlorophenol................................................       17.5         3.6         266        264        268       267       265       269
4-Nitrophenol....................................................       20.3         2.4          65        139        109       140       168       122
--------------------------------------------------------------------------------------------------------------------------------------------------------
Column conditions: Supelcoport (100/120 mesh) coated with 1% SP-1240DA packed in a 1.8 m long x 2mm ID glass column with helium carrier gas at 30 mL/   
  min. flow rate. Column temperature held isothermal at 70 C for 2 min. then programmed at 8 C/min. to 200 C.                                           


                                   Table 6--QC Acceptance Criteria--Method 625                                  
----------------------------------------------------------------------------------------------------------------
                                                              Test                                              
                                                           conclusion   Limits for s    Range for     Range for 
                        Parameter                         (g/  (g/  X(g/     P, Ps   
                                                               L)            L)             L)        (Percent) 
----------------------------------------------------------------------------------------------------------------
Acenaphthene............................................           100          27.6    60.1-132.3        47-145
Acenaphthylene..........................................           100          40.2    53.5-126.0        33-145
Aldrin..................................................           100          39.0     7.2-152.2         D-166
Anthracene..............................................           100          32.0    43.4-118.0        27-133
Benzo(a)anthracene......................................           100          27.6    41.8-133.0        33-143
Benzo(b)fluoranthene....................................           100          38.8    42.0-140.4        24-159
Benzo(k)fluoranthene....................................           100          32.3    25.2-145.7        11-162
Benzo(a)pyrene..........................................           100          39.0    31.7-148.0        17-163
Benzo(ghi)perylene......................................           100          58.9       D-195.0         D-219
Benzyl butyl phthalate..................................           100          23.4       D-139.9         D-152
-BHC...........................................           100          31.5    41.5-130.6        24-149
-BHC...........................................           100          21.6       D-100.0         D-110
Bis(2-chloroethyl) ether................................           100          55.0    42.9-126.0        12-158
Bis(2-chloroethoxy)methane..............................           100          34.5    49.2-164.7        33-184
Bis(2-chloroisopropyl) ethera...........................           100          46.3    62.8-138.6        36-166
Bis(2-ethylhexyl) phthalate.............................           100          41.1    28.9-136.8         8-158
4-Bromophenyl phenyl ether..............................           100          23.0    64.9-114.4        53-127
2-Chloronaphthalene.....................................           100          13.0    64.5-113.5        60-118
4-Chlorophenyl phenyl ether.............................           100          33.4    38.4-144.7        25-158
Chrysene................................................           100          48.3    44.1-139.9        17-168
4,4'-DDD................................................           100          31.0       D-134.5         D-145
4,4'-DDE................................................           100          32.0    19.2-119.7         4-136
4,4'-DDT................................................           100          61.6       D-170.6         D-203
Dibenzo(a,h)anthracene..................................           100          70.0       D-199.7         D-227
Di-n-butyl phthalate....................................           100          16.7     8.4-111.0         1-118
1,2-Dichlorobenzene.....................................           100          30.9    48.6-112.0        32-129
1,3-Dichlorobenzene.....................................           100          41.7    16.7-153.9         D-172
1,4,-Dichlorobenzene....................................           100          32.1    37.3-105.7        20-124

[[Page 216]]

                                                                                                                
3,3'-Dhlorobenzidine....................................           100          71.4     8.2-212.5         D-262
Dieldrin................................................           100          30.7    44.3-119.3        29-136
Diethyl phthalate.......................................           100          26.5       D-100.0         D-114
Dimethyl phthalate......................................           100          23.2       D-100.0         D-112
2,4-Dinitrotoluene......................................           100          21.8    47.5-126.9        39-139
2,6-Dinitrotoluene......................................           100          29.6    68.1-136.7        50-158
Di-n-octyl phthalate....................................           100          31.4    18.6-131.8         4-146
Endosulfan sulfate......................................           100          16.7       D-103.5         D-107
Endrin aldehyde.........................................           100          32.5       D-188.8         D-209
Fluoranthene............................................           100          32.8    42.9-121.3        26-137
Fluorene................................................           100          20.7    71.6-108.4        59-121
Heptachlor..............................................           100          37.2       D-172.2         D-192
Heptachlor epoxide......................................           100          54.7    70.9-109.4        26-155
Hexachlorobenzene.......................................           100          24.9     7.8-141.5         D-152
Hexachlorobutadiene.....................................           100          26.3    37.8-102.2        24-116
Hexachloroethane........................................           100          24.5    55.2-100.0        40-113
Indeno(1,2,3-cd)pyrene..................................           100          44.6       D-150.9         D-171
Isophorone..............................................           100          63.3    46.6-180.2        21-196
Naphthalene.............................................           100          30.1    35.6-119.6        21-133
Nitrobenzene............................................           100          39.3    54.3-157.6        35-180
N-Nitrosodi-n-propylamine...............................           100          55.4    13.6-197.9         D-230
PCB-1260................................................           100          54.2    19.3-121.0         D-164
Phenanthrene............................................           100          20.6    65.2-108.7        54-120
Pyrene..................................................           100          25.2    69.6-100.0        52-115
1,2,4-Trichlorobenzene..................................           100          28.1    57.3-129.2        44-142
4-Chloro-3-methylphenol.................................           100          37.2    40.8-127.9        22-147
2-Chlorophenol..........................................           100          28.7    36.2-120.4        23-134
2,4-Dichlorophenol......................................           100          26.4    52.5-121.7        39-135
2,4-Dimethylphenol......................................           100          26.1    41.8-109.0        32-119
2,4-Dinitrophenol.......................................           100          49.8       D-172.9         D-191
2-Methyl-4,6-dinitrophenol..............................           100          93.2    53.0-100.0         D-181
2-Nitrophenol...........................................           100          35.2    45.0-166.7        29-182
4-Nitrophenol...........................................           100          47.2    13.0-106.5         D-132
Pentachlorophenol.......................................           100          48.9    38.1-151.8        14-176
Phenol..................................................           100          22.6    16.6-100.0         5-112
2,4,6-Trichlorophenol...................................           100          31.7    52.4-129.2        37-144
----------------------------------------------------------------------------------------------------------------
s=Standard deviation for four recovery measurements, in g/L (Section 8.2.4).                           
X=Average recovery for four recovery measurements, in g/L (Section 8.2.4).                             
P, Ps=Percent recovery measured (Section 8.3.2, Section 8.4.2).                                                 
D=Detected; result must be greater than zero.                                                                   
                                                                                                                
Note: These criteria are based directly upon the method performance data in Table 7. Where necessary, the limits
  for recovery have been broadened to assure applicability of the limts to concentrations below those used to   
  develop Table 7.                                                                                              
a The proper chemical name is 2,2oxybis(1-chloropropane).                                                       


                Table 7--Method Accuracy and Precision as Functions of Concentration--Method 625                
----------------------------------------------------------------------------------------------------------------
                                                                   Accuracy, as   Single analyst      Overall   
                            Parameter                               recovery, X   precision, sr'   precision, S 
                                                                  (g/L)  (g/L)  (g/L)
----------------------------------------------------------------------------------------------------------------
Acenaphthene....................................................      0.96C+0.19      0.15X-0.12      0.21X-0.67
Acenaphthylene..................................................      0.89C+0.74      0.24X-1.06      0.26X-0.54
Aldrin..........................................................      0.78C+1.66      0.27X-1.28      0.43X+1.13
Anthracene......................................................      0.80C+0.68      0.21X-0.32      0.27X-0.64
Benzo(a)anthracene..............................................      0.88C-0.60      0.15X+0.93      0.26X-0.28
Benzo(b)fluoranthene............................................      0.93C-1.80      0.22X+0.43      0.29X+0.96
Benzo(k)fluoranthene............................................      0.87C-1.56      0.19X+1.03      0.35X+0.40
Benzo(a)pyrene..................................................      0.90C-0.13      0.22X+0.48      0.32X+1.35
Benzo(ghi)perylene..............................................      0.98C-0.86      0.29X+2.40      0.51X-0.44
Benzyl butyl phthalate..........................................      0.66C-1.68      0.18X+0.94      0.53X+0.92
-BHC...................................................      0.87C-0.94      0.20X-0.58      0.30X-1.94
-BHC...................................................      0.29C-1.09      0.34X+0.86      0.93X-0.17
Bis(2-chloroethyl) ether........................................      0.86C-1.54      0.35X-0.99      0.35X+0.10
Bis(2-chloroethoxy)methane......................................      1.12C-5.04      0.16X+1.34      0.26X+2.01
Bis(2-chloroisopropyl) ethera...................................      1.03C-2.31      0.24X+0.28      0.25X+1.04
Bis(2-ethylhexyl) phthalate.....................................      0.84C-1.18      0.26X+0.73      0.36X+0.67
4-Bromophenyl phenyl ether......................................      0.91C-1.34      0.13X+0.66      0.16X+0.66
2-Chloronaphthalene.............................................      0.89C+0.01      0.07X+0.52      0.13X+0.34
4-Chlorophenyl phenyl ether.....................................      0.91C+0.53      0.20X-0.94      0.30X-0.46
Chrysene........................................................      0.93C-1.00      0.28X+0.13      0.33X-0.09

[[Page 217]]

                                                                                                                
4,4-DDD.........................................................      0.56C-0.40      0.29X-0.32      0.66X-0.96
4,4-DDE.........................................................      0.70C-0.54      0.26X-1.17      0.39X-1.04
4,4-DDT.........................................................      0.79C-3.28      0.42X+0.19      0.65X-0.58
Dibenzo(a,h)anthracene..........................................      0.88C+4.72      0.30X+8.51      0.59X+0.25
Di-n-butyl phthalate............................................      0.59C+0.71      0.13X+1.16      0.39X+0.60
1,2-Dichlorobenzene.............................................      0.80C+0.28      0.20X+0.47      0.24X+0.39
1,3-Dichlorobenzene.............................................      0.86C-0.70      0.25X+0.68      0.41X+0.11
1,4-Dichlorobenzene.............................................      0.73C-1.47      0.24X+0.23      0.29X+0.36
3,3-Dichlorobenzidine...........................................     1.23C-12.65      0.28X+7.33      0.47X+3.45
Dieldrin........................................................      0.82C-0.16      0.20X-0.16      0.26X-0.07
Diethyl phthalate...............................................      0.43C+1.00      0.28X+1.44      0.52X+0.22
Dimethyl phthalate..............................................      0.20C+1.03      0.54X+0.19      1.05X-0.92
2,4-Dinitrotoluene..............................................      0.92C-4.81      0.12X+1.06      0.21X+1.50
2,6-Dinitrotoluene..............................................      1.06C-3.60      0.14X+1.26      0.19X+0.35
Di-n-octyl phthalate............................................      0.76C-0.79      0.21X+1.19      0.37X+1.19
Endosulfan sulfate..............................................      0.39C+0.41      0.12X+2.47      0.63X-1.03
Endrin aldehyde.................................................      0.76C-3.86      0.18X+3.91      0.73X-0.62
Fluoranthene....................................................      0.81C+1.10      0.22X-0.73      0.28X-0.60
Fluorene........................................................      0.90C-0.00      0.12X+0.26      0.13X+0.61
Heptachlor......................................................      0.87C-2.97      0.24X-0.56      0.50X-0.23
Heptachlor epoxide..............................................      0.92C-1.87      0.33X-0.46      0.28X+0.64
Hexachlorobenzene...............................................      0.74C+0.66      0.18X-0.10      0.43X-0.52
Hexachlorobutadiene.............................................      0.71C-1.01      0.19X+0.92      0.26X+0.49
Hexachloroethane................................................      0.73C-0.83      0.17X+0.67      0.17X+0.80
Indeno(1,2,3-cd)pyrene..........................................      0.78C-3.10      0.29X+1.46      0.50X+0.44
Isophorone......................................................      1.12C+1.41      0.27X+0.77      0.33X+0.26
Naphthalene.....................................................      0.76C+1.58      0.21X-0.41      0.30X-0.68
Nitrobenzene....................................................      1.09C-3.05      0.19X+0.92      0.27X+0.21
N-Nitrosodi-n-propylamine.......................................      1.12C-6.22      0.27X+0.68      0.44X+0.47
PCB-1260........................................................     0.81C-10.86      0.35X+3.61      0.43X+1.82
Phenanthrene....................................................      0.87C-0.06      0.12X+0.57      0.15X+0.25
Pyrene..........................................................      0.84C-0.16      0.16X+0.06      0.15X+0.31
1,2,4-Trichlorobenzene..........................................      0.94C-0.79      0.15X+0.85      0.21X+0.39
4-Chloro-3-methylphenol.........................................      0.84C+0.35      0.23X+0.75      0.29X+1.31
2-Chlorophenol..................................................      0.78C+0.29      0.18X+1.46      0.28X+0.97
2,4-Dichlorophenol..............................................      0.87C+0.13      0.15X+1.25      0.21X+1.28
2,4-Dimethylphenol..............................................      0.71C+4.41      0.16X+1.21      0.22X+1.31
2,4-Dinitrophenol...............................................     0.81C-18.04      0.38X+2.36     0.42X+26.29
2-Methyl-4,6-Dinitrophenol......................................     1.04C-28.04     0.05X+42.29     0.26X+23.10
2-Nitrophenol...................................................      1.07C-1.15      0.16X+1.94      0.27X+2.60
4-Nitrophenol...................................................      0.61C-1.22      0.38X+2.57      0.44X+3.24
Pentachlorophenol...............................................      0.93C+1.99      0.24X+3.03      0.30X+4.33
Phenol..........................................................      0.43C+1.26      0.26X+0.73      0.35X+0.58
2,4,6-Trichlorophenol...........................................      0.91C-0.18      0.16X+2.22      0.22X+1.81
----------------------------------------------------------------------------------------------------------------
X=Expected recovery for one or more measurements of a sample containing a concentration of C, in g/L.  
sr=Expected single analyst standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
S=Expected interlaboratory standard deviation of measurements at an average concentration found of X, in g/L.                                                                                                        
C=True value for the concentration, in g/L.                                                            
X=Average recovery found for measurements of samples containing a concentration of C, in g/L.          
a The proper chemical name is 2,2oxybis(1-chloropropane).                                                       


           Table 8--Suggested Internal and Surrogate Standards          
------------------------------------------------------------------------
           Base/neutral fraction                    Acid fraction       
------------------------------------------------------------------------
Aniline-d5................................  2-Fluorophenol.             
Anthracene-d10............................  Pentafluorophenol.          
Benzo(a)anthracene-d12....................  Phenol-d5                   
4,4-Dibromobiphenyl.......................  2-Perfluoromethyl phenol.   
4,4-Dibromooctafluorobiphenyl.............  ............................
Decafluorobiphenyl........................  ............................
2,2\1\-Difluorobiphenyl...................  ............................
4-Fluoroaniline...........................  ............................
1-Fluoronaphthalene.......................  ............................
2-Fluoronaphthalene.......................  ............................
Naphthalene-d8............................  ............................
Nitrobenzene-d5...........................  ............................
2,3,4,5,6-Pentafluorobiphenyl.............  ............................
Phenanthrene-d10..........................  ............................
Pyridine-d5...............................  ............................
------------------------------------------------------------------------


            Table 9--DFTPP Key Masses and Abundance Criteria            
------------------------------------------------------------------------
  Mass                        m/z Abundance criteria                    
------------------------------------------------------------------------
51.....  30-60 percent of mass 198.                                     

[[Page 218]]

                                                                        
68.....  Less than 2 percent of mass 69.                                
70.....  Less than 2 percent of mass 69.                                
127....  40-60 percent of mass 198.                                     
197....  Less than 1 percent of mass 198.                               
198....  Base peak, 100 percent relative abundance.                     
199....  5-9 percent of mass 198.                                       
275....  10-30 percent of mass 198.                                     
365....  Greater than 1 percent of mass 198.                            
441....  Present but less than mass 443.                                
442....  Greater than 40 percent of mass 198.                           
443....  17-23 percent of mass 442.                                     
------------------------------------------------------------------------


[[Page 219]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.042


[[Page 220]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.043


[[Page 221]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.044


[[Page 222]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.045


[[Page 223]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.046


[[Page 224]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.047


[[Page 225]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.048


[[Page 226]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.049


[[Page 227]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.050


[[Page 228]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.051


[[Page 229]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.052


[[Page 230]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.053


[[Page 231]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.054


[[Page 232]]

 Method 1624 Revision B--Volatile Organic Compounds by Isotope Dilution 
                                  GC/MS

                        1.  Scope and Application

    1.1  This method is designed to determine the volatile toxic organic 
pollutants associated with the 1976 Consent Decree and additional 
compounds amenable to purge and trap gas chromatography-mass 
spectrometry (GC/MS).
    1.2  The chemical compounds listed in table 1 may be determined in 
municipal and industrial discharges by this method. The methmd is 
designed to meet the survey requirements of Effluent Guidelines Division 
(EGD) and the National Pollutants Discharge Elimination System (NPDES) 
under 40 CFR 136.1 and 136.5. Any modifications of this method, beyond 
those expressly permitted, shall be considered as major modifications 
subject to application and approval of alternate test procedures under 
40 CFR 136.4 and 136.5.
    1.3  The detection limit of this method is usually dependent on the 
level of interferences rather than instrumental limitations. The limits 
in table 2 represent the minimum quantity that can be detected with no 
interferences present.
    1.4  The GC/MS portions of this method are for use only by analysts 
experienced with GC/MS or under the close supervision of such qualified 
persons. Laboratories unfamiliar with the analyses of environmental 
samples by GC/MS should run the performance tests in reference 1 before 
beginning.

                          2.  Summary of Method

    2.1  Stable isotopically labeled analogs of the compounds of 
interest are added to a 5 mL water sample. The sample is purged at 20-25 
 deg.C with an inert gas in a specially designed chamber. The volatile 
organic compounds are transferred from the aqueous phase into the 
gaseous phase where they are passed into a sorbent column and trapped. 
After purging is completed, the trap is backflushed and heated rapidly 
to desorb the compounds into a gas chromatograph (GC). The compounds are 
separated by the GC and detected by a mass spectrometer (MS) (references 
2 and 3). The labeled compounds serve to correct the variability of the 
analytical technique.
    2.2  Identification of a compound (qualitative analysis) is 
performed by comparing the GC retention time and the background 
corrected characteristic spectral masses with those of authentic 
standards.
    2.3  Quantitative analysis is performed by GC/MS using extracted ion 
current profile (EICP) areas. Isotope dilution is used when labeled 
compounds are available; otherwise, an internal standard method is used.
    2.4  Quality is assured through reproducible calibration and testing 
of the purge and trap and GC/MS systems.

                   3.  Contamination and Interferences

    3.1  Impurities in the purge gas, organic compounds out-gassing from 
the plumbing upstream of the trap, and solvent vapors in the laboratory 
account for the majority of contamination problems. The analytical 
system is demonstrated to be free from interferences under conditions of 
the analysis by analyzing blanks initially and with each sample lot 
(samples analyzed on the same 8 hr shift), as described in Section 8.5.
    3.2  Samples can be contaminated by diffusion of volatile organic 
compounds (particularly methylene chloride) through the bottle seal 
during shipment and storage. A field blank prepared from reagent water 
and carried through the sampling and handling protocol serves as a check 
on such contamination.
    3.3  Contamination by carry-over can occur when high level and low 
level samples are analyzed sequentially. To reduce carry-over, the 
purging device and sample syringe are rinsed between samples with 
reagent water. When an unusually concentrated sample is encountered, it 
is followed by analysis of a reagent water blank to check for carry-
over. For samples containing large amounts of water soluble materials, 
suspended solids, high boiling compounds, or high levels or purgeable 
compounds, the purge device is washed with soap solution, rinsed with 
tap and distilled water, and dried in an oven at 100-125  deg.C. The 
trap and other parts of the system are also subject to contamination; 
therefore, frequent bakeout and purging of the entire system may be 
required.
    3.4  Interferences resulting from samples will vary considerably 
from source to source, depending on the diversity of the industrial 
complex or municipality being sampled.

                               4.  Safety

    4.1  The toxicity or carcinogenicity of each compound or reagent 
used in this method has not been precisely determined; however, each 
chemical compound should be treated as a potential health hazard. 
Exposure to these compounds should be reduced to the lowest possible 
level. The laboratory is responsible for maintaining a current awareness 
file of OSHA regulations regarding the safe handling of the chemicals 
specified in this method. A reference file of data handling sheets 
should also be made available to all personnel involved in these 
analyses. Additional information on laboratory safety can be found in 
references 4-6.
    4.2  The following compounds covered by this method have been 
tentatively classified as known or suspected human or mammalian 
carcinogens: benzene, carbon tetrachloride,

[[Page 233]]

chloroform, and vinyl chloride. Primary standards of these toxic 
compounds should be prepared in a hood, and a NIOSH/MESA approved toxic 
gas respirator should be worn when high concentrations are handled.

                       5.  Apparatus and Materials

    5.1  Sample bottles for discrete sampling.
    5.1.1  Bottle--25 to 40 mL with screw cap (Pierce 13075, or 
equivalent). Detergent wash, rinse with tap and distilled water, and dry 
at >105  deg.C for one hr minimum before use.
    5.1.2  Septum--Teflon-faced silicone (Pierce 12722, or equivalent), 
cleaned as above and baked at 100-200  deg.C, for one hour minimum.
    5.2  Purge and trap device--consists of purging device, trap, and 
desorber. Complete devices are commercially available.
    5.2.1  Purging device--designed to accept 5 mL samples with water 
column at least 3 cm deep. The volume of the gaseous head space between 
the water and trap shall be less than 15 mL. The purge gas shall be 
introduced less than 5 mm from the base of the water column and shall 
pass through the water as bubbles with a diameter less than 3 mm. The 
purging device shown in Figure 1 meets these criteria.
    5.2.2  Trap--25 to 30 cm x 2.5 mm i.d. minimum, containing the 
following:
    5.2.2.1  Methyl silicone packing--one  0.2 cm, 3 percent 
OV-1 on 60/80 mesh Chromosorb W, or equivalent.
    5.2.2.2  Porous polymer--15  1.0 cm, Tenax GC (2,6-
diphenylene oxide polymer), 60/80 mesh, chromatographic grade, or 
equivalent.
    5.2.2.3  Silica gel--8  1.0 cm, Davison Chemical, 35/60 
mesh, grade 15, or equivalent. The trap shown in Figure 2 meets these 
specifications.
    5.2.3  Desorber--shall heat the trap to 175  5  deg.C in 
45 seconds or less. The polymer section of the trap shall not exceed 180 
 deg.C, and the remaining sections shall not exceed 220  deg.C. The 
desorber shown in Figure 2 meets these specifications.
    5.2.4  The purge and trap device may be a separate unit or coupled 
to a GC as shown in Figures 3 and 4.
    5.3  Gas chromatograph--shall be linearly temperature programmable 
with initial and final holds, shall contain a glass jet separator as the 
MS interface, and shall produce results which meet the calibration 
(Section 7), quality assurance (Section 8), and performance tests 
(Section 11) of this method.
    5.3.1  Column--2.8  0.4 m x 2  0.5 mm i. d. 
glass, packekd with one percent SP-1000 on Carbopak B, 60/80 mesh, or 
equivalent.
    5.4  Mass spectrometer--70 eV electron impact ionization; shall 
repetitively scan from 20 to 250 amu every 2-3 seconds, and produce a 
unit resolution (valleys between m/z 174-176 less than 10 percent of the 
height of the m/z 175 peak), background corrected mass spectrum from 50 
ng 4-bromo-fluorobenzene (BFB) injected into the GC. The BFB spectrum 
shall meet the mass-intensity criteria in Table 3. All portions of the 
GC column, transfer lines, and separator which connect the GC column to 
the ion source shall remain at or above the column temperature during 
analysis to preclude condensation of less volatile compounds.
    5.5  Data system--shall collect and record MS data, store mass 
intensity data in spectral libraries, process GC/MS data and generate 
reports, and shall calculate and record response factors.
    5.5.1  Data acquisition--mass spectra shall be collected 
continuously throughout the analysis and stored on a mass storage 
device.
    5.5.2  Mass spectral libraries--user created libraries containing 
mass spectra obtained from analysis of authentic standards shall be 
employed to reverse search GC/MS runs for the compounds of interest 
(Section 7.2).
    5.5.3  Data processing--the data system shall be used to search, 
locate, identify, and quantify the compounds of interest in each GC/MS 
analysis. Software routines shall be employed to compute retention times 
and EICP areas. Displays of spectra, mass chromatograms, and library 
comparisons are required to verify results.
    5.5.4  Response factors and multipoint calibrations--the data system 
shall be used to record and maintain lists of response factors (response 
ratios for isotope dilution) and generate multi-point calibration curves 
(Section 7). Computations of relative standard deviation (coefficient of 
variation) are useful for testing calibration linearity. Statistics on 
initial and on-going performance shall be maintained (Sections 8 and 
11).
    5.6  Syringes--5 mL glass hypodermic, with Luer-lok tips.
    5.7  Micro syringes--10, 25, and 100 uL.
    5.8  Syringe valves--2-way, with Luer ends (Telfon or Kel-F).
    5.9  Syringe--5 mL, gas-tight, with shut-off valve.
    5.10  Bottles--15 mL., screw-cap with Telfon liner.
    5.11  Balance--analytical, capable of weighing 0.1 mg.

                       6.  Reagents and Standards

    6.1  Reagent water--water in which the compounds of interest and 
interfering compounds are not detected by this method (Section 11.7). It 
may be generated by any of the following methods:
    6.1.1  Activated carbon--pass tap water through a carbon bed (Calgon 
Filtrasorb-300, or equivalent).
    6.1.2  Water purifier--pass tap water through a purifier (Millipore 
Super Q, or equivalent).
    6.1.3  Boil and purge--heat tap water to 90-100  deg.C and bubble 
contaminant free inert gas through it for approx one hour. While still

[[Page 234]]

hot, transfer the water to screw-cap bottles and seal with a Teflon-
lined cap.
    6.2  Sodium thiosulfate--ACS granular.
    6.3  Methanol--pesticide quality or equivalent.
    6.4  Standard solutions--purchased as solution or mixtures with 
certification to their purity, concentration, and authenticity, or 
prepared from materials of known purity and composition. If compound 
purity is 96 percent or greater, the weight may be used without 
correction to calculate the concentration of the standard.
    6.5  Preparation of stock solutions--prepare in methanol using 
liquid or gaseous standards per the steps below. Observe the safety 
precautions given in Section 4.
    6.5.1  Place approx 9.8 mL of methanol in a 10 mL ground glass 
stoppered volumetric flask. Allow the flask to stand unstoppered for 
approximately 10 minutes or until all methanol wetted surfaces have 
dried. In each case, weigh the flask, immediately add the compound, then 
immediately reweigh to prevent evaporation losses from affecting the 
measurement.
    6.5.1.1  Liquids--using a 100 L syringe, permit 2 drops of 
liquid to fall into the methanol without contacting the leck of the 
flask. Alternatively, inject a known volume of the compound into the 
methanol in the flask using a micro-syringe.
    6.5.1.2  Gases (chloromethane, bromomethane, chloroethane, vinyl 
chloride)--fill a valved 5 mL gas-tight syringe with the compound. Lower 
the needle to approximately 5 mm above the methanol meniscus. Slowly 
introduce the compound above the surface of the meniscus. The gas will 
dissolve rapidly in the methanol.
    6.5.2  Fill the flask to volume, stopper, then mix by inverting 
several times. Calculate the concentration in mg/mL (g/
L ) from the weight gain (or density if a known volume was 
injected).
    6.5.3  Transfer the stock solution to a Teflon sealed screw-cap-
bottle. Store, with minimal headspace, in the dark at -10 to -20  deg.C.
    6.5.4  Prepare fresh standards weekly for the gases and 2-
chloroethylvinyl ether. All other standards are replaced after one 
month, or sooner if comparison with check standards indicate a change in 
concentration. Quality control check standards that can be used to 
determine the accuracy of calibration standards are available from the 
US Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory, Cincinnati, Ohio.
    6.6  Labeled compound spiking solution--from stock standard 
solutions prepared as above, or from mixtures, prepare the spiking 
solution to contain a concentration such that a 5-10 L spike 
into each 5 mL sample, blank, or aqueous standard analyzed will result 
in a concentration of 20 g/L of each labeled compound. For the 
gases and for the water soluble compounds (acrolein, acrylonitrile, 
acetone, diethyl ether, and MEK), a concentration of 100 g/L 
may be used. Include the internal standards (Section 7.5) in this 
solution so that a concentration of 20 g/L in each sample, 
blank, or aqueous standard will be produced.
    6.7  Secondary standards--using stock solutions, prepare a secondary 
standard in methanol to contain each pollutant at a concentration of 500 
g/mL For the gases and water soluble compounds (Section 6.6), a 
concentration of 2.5 mg/mL may be used.
    6.7.1  Aqueous calibration standards--using a 25 L syringe, 
add 20 L of the secondary standard (Section 6.7) to 50, 100, 
200, 500, and 1000 mL of reagent water to produce concentrations of 200, 
100, 50, 20, and 10 g/L, respectively. If the higher 
concentration standard for the gases and water soluble compounds was 
chosen (Section 6.6), these compounds will be at concentrations of 1000, 
500, 250, 100, and 50 g/L in the aqueous calibration standards.
    6.7.2  Aqueous performance standard--an aqueous standard containing 
all pollutants, internal standards, labeled compounds, and BFB is 
prepared daily, and analyzed each shift to demonstrate performance 
(Section 11). This standard shall contain either 20 or 100 g/L 
of the labeled and pollutant gases and water soluble compounds, 10 
g/L BFB, and 20 g/L of all other pollutants, labeled 
compounds, and internal standards. It may be the nominal 20 g/L 
aqueous calibration standard (Section 6.7.1).
    6.7.3  A methanolic standard containing all pollutants and internal 
standards is prepared to demonstrate recovery of these compounds when 
syringe injection and purge and trap analyses are compared. This 
standard shall contain either 100 g/mL or 500 g/mL of 
the gases and water soluble compounds, and 100 g/mL of the 
remaining pollutants and internal standards (consistent with the amounts 
in the aqueous performance standard in 6.7.2).
    6.7.4  Other standards which may be needed are those for test of BFB 
performance (Section 7.1) and for collection of mass spectra for storage 
in spectral libraries (Section 7.2).

                             7.  Calibration

    7.1  Assemble the gas chromatographic apparatus and establish 
operating conditions given in table 2. By injecting standards into the 
GC, demonstrate that the analytical system meets the detection limits in 
table 2 and the mass-intensity criteria in table 3 for 50 ng BFB.
    7.2  Mass spectral libraries--detection and identification of the 
compound of interest are dependent upon the spectra stored in user 
created libraries.

[[Page 235]]

    7.2.1  Obtain a mass spectrum of each pollutant and labeled compound 
and each internal standard by analyzing an authentic standard either 
singly or as part of a mixture in which there is no interference between 
closely eluted components. That only a single compound is present is 
determined by examination of the spectrum. Fragments not attributable to 
the compound under study indicate the presence of an interfering 
compound. Adjust the analytical conditions and scan rate (for this test 
only) to produce an undistorted spectrum at the GC peak maximum. An 
undistorted spectrum will usually be obtained if five complete spectra 
are collected across the upper half of the GC peak. Software algorithms 
designed to ``enhance'' the spectrum may eliminate distortion, but may 
also eliminate authentic m/z's or introduce other distortion.
    7.2.3  The authentic reference spectrum is obtained under BFB tuning 
conditions (Section 7.1 and table 3) to normalize it to spectra from 
other instruments.
    7.2.4  The spectrum is edited by saving the 5 most intense mass 
spectral peaks and all other mass spectral peaks greater than 10 percent 
of the base peak. This spectrum is stored for reverse search and for 
compound confirmation.
    7.3  Assemble the purge and trap device. Pack the trap as shown in 
Figure 2 and condition overnight at 170-180  deg.C by backflushing with 
an inert gas at a flow rate of 20-30 mL/min. Condition traps daily for a 
minimum of 10 minutes prior to use.
    7.3.1  Analyze the aqueous performance standard (Section 6.7.2) 
according to the purge and trap procedure in Section 10. Compute the 
area at the primary m/z (table 4) for each compound. Compare these areas 
to those obtained by injecting one L of the methanolic standard 
(Section 6.7.3) to determine compound recovery. The recovery shall be 
greater than 20 percent for the water soluble compounds, and 60-110 
percent for all other compounds. This recovery is demonstrated initially 
for each purge and trap GC/MS system. The test is repeated only if the 
purge and trap or GC/MS systems are modified in any way that might 
result in a change in recovery.
    7.3.2  Demonstrate that 100 ng toluene (or toluene-d8) produces an 
area at m/z 91 (or 99) approx one-tenth that required to exceed the 
linear range of the system. The exact value must be determined by 
experience for each instrument. It is used to match the calibration 
range of the instrument to the analytical range and detection limits 
required.
    7.4  Calibration by isotope dilution--the isotope dilution approach 
is used for the purgeable organic compounds when appropriate labeled 
compounds are available and when interferences do not preclude the 
analysis. If labeled compounds are not available, or interferences are 
present, internal standard methods (Section 7.5 or 7.6) are used. A 
calibration curve encompassing the concentration range of interest is 
prepared for each compound determined. The relative response (RR) vs 
concentration (g/L) is plotted or computed using a linear 
regression. An example of a calibration curve for toluene using toluene-
d8 is given in figure 5. Also shown are the 10 percent error 
limits (dotted lines). Relative response is determined according to the 
procedures described below. A minimum of five data points are required 
for calibration (Section 7.4.4).
    7.4.1  The relative response (RR) of pollutant to labeled compound 
is determined from isotope ratio values calculated from acquired data. 
Three isotope ratios are used in this process:

    Rx=the isotope ratio measured in the pure pollutant (figure 
6A).
    Ry=the isotope ratio of pure labeled compound (figure 6B).
    Rm=the isotope ratio measured in the analytical mixture of the 
pollutant and labeled compounds (figure 6C).

    The correct way to calculate RR is: RR=(Ry-Rm) 
(Rx+1)/(Rm-Rx)(Ry+1) If Rm is not between 
2Ry and 0.5Rx, the method does not apply and the sample is 
analyzed by internal or external standard methods (Section 7.5 or 7.6).
    7.4.2  In most cases, the retention times of the pollutant and 
labeled compound are the same and isotope ratios (R's) can be calculated 
from the EICP areas, where: R=(area at m1/z)/(area at m2/z) If 
either of the areas is zero, it is assigned a value of one in the 
calculations; that is, if: area of m1/z=50721, and area of m2/
z=0, then R=50721/1=50720. The m/z's are always selected such that 
Rx>Ry. When there is a difference in retention times (RT) 
between the pollutant and labeled compounds, special precautions are 
required to determine the isotope ratios.
    Rx, Ry, and Rm are defined as follows:

    Rx=[area m1/z (at RT1)]/1
    Ry=1/[area m2/z (at RT2)]
    Rm=[area m1/z (at RT1)]/[area m2/z (at 
RT2)]

    7.4.3  An example of the above calculations can be taken from the 
data plotted in figure 6 for toluene and toluene-d8. For these data, 
Rx=168920/1=168900, Ry=1/60960=0.00001640, and Rm=96868/
82508=1.174. The RR for the above data is then calculated using the 
equation given in Section 7.4.1. For the example, RR=1.174.
    Note: Not all labeled compounds elute before their pollutant 
analogs.
    7.4.4  To calibrate the analytical system by isotope dilution, 
analyze a 5 mL aliquot of each of the aqueous calibration standards 
(Section 6.7.1) spiked with an appropriate constant amount of the 
labeled compound spiking solution (Section 6.6), using the purge and 
trap procedure in section 10. Compute the RR at each concentration.

[[Page 236]]

    7.4.5  Linearity--if the ratio of relative response to concentration 
for any compound is constant (less than 20 percent coefficient of 
variation) over the 5 point calibration range, an averaged relative 
response/concentration ratio may be used for that compound; otherwise, 
the complete calibration curve for that compound shall be used over the 
5 point calibration range.
    7.5  Calibration by internal standard--used when criteria for 
isotope dilution (Section 7.4) cannot be met. The method is applied to 
pollutants having no labeled analog and to the labeled compounds. The 
internal standards used for volatiles analyses are bromochloromethane, 
2-bromo-1-chloropropane, and 1,4-dichlorobutane. Concentrations of the 
labeled compounds and pollutants without labeled analogs are computed 
relative to the nearest eluted internal standard, as shown in table 2.
    7.5.1  Response factors--calibration requires the determination of 
response factors (RF) which are defined by the following equation:
    RF=(AsxCis)/(AisxCs), where As is the EICP 
area at the characteristic m/z for the compound in the daily standard. 
Ais is the EICP area at the characteristic m/z for the internal 
standard.
    Cis is the concentration (ug/L) of the internal standard
    Cs is the concentration of the pollutant in the daily standard.
    7.5.2  The response factor is determined at 10, 20, 50, 100, and 200 
ug/L for the pollutants (optionally at five times these concentrations 
for gases and water soluble pollutants--see Section 6.7), in a way 
analogous to that for calibration by isotope dilution (Section 7.4.4). 
The RF is plotted against concentration for each compound in the 
standard (Cs) to produce a calibration curve.
    7.5.3  Linearity--if the response factor (RF) for any compound is 
constant (less than 35 percent coefficient of variation) over the 5 
point calibration range, an averaged response factor may be used for 
that compound; otherwise, the complete calibration curve for that 
compound shall be used over the 5 point range.
    7.6  Combined calibration--by adding the isotopically labeled 
compounds and internal standards (Section 6.6) to the aqueous 
calibration standards (Section 6.7.1), a single set of analyses can be 
used to produce calibration curves for the isotope dilution and internal 
standard methods. These curves are verified each shift (Section 11.5) by 
purging the aqueous performance standard (Section 6.7.2). Recalibration 
is required only if calibration and on-going performance (Section 11.5) 
criteria cannot be met.

                  8.  Quality Assurance/Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality assurance program. The minimum requirements of this 
program consist of an initial demonstration of laboratory capability, 
analysis of samples spiked with labeled compounds to evaluate and 
document data quality, and analysis of standards and blanks as tests of 
continued performance. Laboratory performance is compared to established 
performance criteria to determine if the results of analyses meet the 
performance characteristics of the method.
    8.1.1  The analyst shall make an initial demonstration of the 
ability to generate acceptable accuracy and precision with this method. 
This ability is established as described in Section 8.2.
    8.1.2  The analyst is permitted to modify this method to improve 
separations or lower the costs of measurements, provided all performance 
specifications are met. Each time a modification is made to the method, 
the analyst is required to repeat the procedure in Section 8.2 to 
demonstrate method performance.
    8.1.3  Analyses of blanks are required to demonstrate freedom from 
contamination and that the compounds of interest and interfering 
compounds have not been carried over from a previous analysis (Section 
3). The procedures and criteria for analysis of a blank are described in 
Sections 8.5 and 11.7.
    8.1.4  The laboratory shall spike all samples with labeled compounds 
to monitor method performance. This test is described in Section 8.3. 
When results of these spikes indicate atypical method performance for 
samples, the samples are diluted to bring method performance within 
acceptable limits (Section 14.2).
    8.1.5  The laboratory shall, on an on-going basis, demonstrate 
through the analysis of the aqueous performance standard (Section 6.7.2) 
that the analysis system is in control. This procedure is described in 
Sections 11.1 and 11.5.
    8.1.6  The laboratory shall maintain records to define the quality 
of data that is generated. Development of accuracy statements is 
described in Sections 8.4 and 11.5.2.
    8.2  Initial precision and accuracy--to establish the ability to 
generate acceptable precision and accuracy, the analyst shall perform 
the following operations:
    8.2.1  Analyze two sets of four 5-mL aliquots (8 aliquots total) of 
the aqueous performance standard (Section 6.7.2) according to the method 
beginning in Section 10.
    8.2.2  Using results of the first set of four analyses in Section 
8.2.1, compute the average recovery (X) in g/L and the standard 
deviation of the recovery (s) in g/L for each compound, by 
isotope dilution for polluitants with a labeled analog, and by internal 
standard for labeled compounds and pollutants with no labeled analog.

[[Page 237]]

    8.2.3  For each compound, compare s and X with the corresponding 
limits for initial precision and accuracy found in table 5. If s and X 
for all compounds meet the acceptance criteria, system performance is 
acceptable and analysis of blanks and samples may begin. If individual X 
falls outside the range for accuracy, system performance is unacceptable 
for that compound.

    Note: The large number of compounds in table 5 present a substantial 
probability that one or more will fail one of the acceptance criteria 
when all compoulds are analyzed. To determine if the analytical system 
is out of control, or if the failure can be attributed to probability, 
proceed as follows:

    8.2.4  Using the results of the second set of four analyses, compute 
s and X for only those compounds which failed the test of the first set 
of four analyses (Section 8.2.3). If these compounds now pass, system 
performance is acceptable for all compounds and analysis of blanks and 
samples may begin. If, however, any of the same compounds fail again, 
the analysis system is not performing properly for the compound(s) in 
question. In this event, correct the problem and repeat the entire test 
(Section 8.2.1).
    8.3  The laboratory shall spike all samples with labeled compounds 
to assess method performance on the sample matrix.
    8.3.1  Spike and analyze each sample according to the method 
beginning in Section 10.
    8.3.2  Compute the percent recovery (P) of the labeled compounds 
using the internal standard method (Section 7.5).
    8.3.3  Compare the percent recovery for each compound with the 
corresponding labeled compound recovery limit in table 5. If the 
recovery of any compound falls outside its warning limit, method 
performance is unacceptable for that compound in that sample. Therefore, 
the sample matrix is complex and the sample is to be diluted and 
reanalyzed, per Section 14.2.
    8.4  As part of the QA program for the laboratory, method accuracy 
for wastewater samples shall be assessed and records shall be 
maintained. After the analysis of five wastewater samples for which the 
labeled compounds pass the tests in Section 8.3.3, compute the average 
percent recovery (P) and the standard deviation of the percent recovery 
(sp) for the labeled compounds only. Express the accuracy 
assessment as a percent recovery interval from P-2sp to P+2sp. 
For example, if P=90% and sp=10%, the accuracy interval is 
expressed as 70-110%. Update the accuracy assessment for each compound 
on a regular basis (e.g. after each 5-10 new accuracy measurements).
    8.5  Blanks--reagent water blanks are analyzed to demonstrate 
freedom from carry-over (Section 3) and contamination.
    8.5.1  The level at which the purge and trap system will carry 
greater than 5 g/L of a pollutant of interest (table 1) into a 
succeeding blank shall be determined by analyzing successively larger 
concentrations of these compounds. When a sample contains this 
concentration or more, a blank shall be analyzed immediately following 
this sample to demonstrate no carry-over at the 5 g/L level.
    8.5.2  With each sample lot (samples analyzed on the same 8 hr 
shift), a blank shall be analyzed immediately after analysis of the 
aqueous performance standard (Section 11.1) to demonstrate freedom from 
contamination. If any of the compounds of interest (table 1) or any 
potentially interfering compound is found in a blank at greater than 10 
g/L (assuming a response factor of 1 relative to the nearest 
eluted internal standard for compounds not listed in table 1), analysis 
of samples is halted until the source of contamination is eliminated and 
a blank shows no evidence of contamination at this level.
    8.6  The specifications contained in this method can be met if the 
apparatus used is calibrated properly, then maintained in a calibrated 
state.
    The standards used for calibration (Section 7), calibration 
verification (Section 11.5) and for initial (Section 8.2) and on-going 
(Section 11.5) precision and accuracy should be identical, so that the 
most precise results will be obtained. The GC/MS instrument in 
particular will provide the most reproducible results if dedicated to 
the settings and conditions required for the analyses of volatiles by 
this method.
    8.7  Depending on specific program requirements, field replicates 
may be collected to determine the precision of the sampling technique, 
and spiked samples may be required to determine the accuracy of the 
analysis when internal or external standard methods are used.

            9.  Sample Collection, Preservation, and Handling

    9.1  Grab samples are collected in glass containers having a total 
volume greater than 20 mL. Fill sample bottles so that no air bubbles 
pass through the sample as the bottle is filled. Seal each bottle so 
that no air bubbles are entrapped. Maintain the hermetic seal on the 
sample bottle until time of analysis.
    9.2  Samples are maintained at 0-4  deg.C from the time of 
collection until analysis. If the sample contains residual chlorine, add 
sodium thiosulfate preservative (10 mg/40 mL) to the empty sample 
bottles just prior to shipment to the sample site. EPA Methods 330.4 and 
330.5 may be used for measurement of residual chlorine (Reference 8). If 
preservative has been added, shake bottle vigorously for one minute 
immediately after filling.

[[Page 238]]

    9.3  Experimental evidence indicates that some aromatic compounds, 
notably benzene, toluene, and ethyl benzene are susceptible to rapid 
biological degradation under certain environmental conditions. 
Refrigeration alone may not be adequate to preserve these compounds in 
wastewaters for more than seven days. For this reason, a separate sample 
should be collected, acidified, and analyzed when these aromatics are to 
be determined. Collect about 500 mL of sample in a clean container.
    Adjust the pH of the sample to about 2 by adding HCl (1+1) while 
stirring. Check pH with narrow range (1.4 to 2.8) pH paper. Fill a 
sample container as described in Section 9.1. If residual chlorine is 
present, add sodium thiosulfate to a separate sample container and fill 
as in Section 9.1.
    9.4  All samples shall be analyzed within 14 days of collection.

                  10.  Purge, Trap, and GC/MS Analysis

    10.1  Remove standards and samples from cold storage and bring to 
20-25  deg..
    10.2  Adjust the purge gas flow rate to 40 4 mL/min. 
Attach the trap inlet to the purging device and set the valve to the 
purge mode (figure 3). Open the syringe valve located on the purging 
device sample introduction needle (figure 1).
    10.3  Remove the plunger from a 5-mL syringe and attach a closed 
syringe valve. Open the sample bottle and carefully pour the sample into 
the syringe barrel until it overflows. Replace the plunger and compress 
the sample. Open the syringe valve and vent any residual air while 
adjusting the sample volume to 5.0 mL. Because this process of taking an 
aliquot destroys the validity of the sample for future analysis, fill a 
second syringe at this time to protect against possible loss of data. 
Add an appropriate amount of the labeled compound spiking solution 
(Section 6.6) through the valve bore, then close the valve.
    10.4  Attach the syringe valve assembly to the syringe valve on the 
purging device. Open both syringe valves and inject the sample into the 
purging chamber.
    10.5  Close both valves and purge the sample for 11.0  
0.1 minutes at 20-25  deg.C.
    10.6  After the 11 minute purge time, attach the trap to the 
chromatograph and set the purge and trap apparatus to the desorb mode 
(figure 4). Desorb the trapped compounds into the GC column by heating 
the trap to 170-180  deg.C while backflushing with carrier gas at 20-60 
mL/min for four minutes. Start MS data acquisition upon start of the 
desorb cycle, and start the GC column temperature program 3 minutes 
later. Table 1 summarizes the recommended operating conditions for the 
gas chromatograph. Included in this table are retention times and 
detection limits that were achieved under these conditions. Other 
columns may be used provided the requirements in Section 8 can be met. 
If the priority pollutant gases produce GC peaks so broad that the 
precision and recovery specifications (Section 8.2) cannot be met, the 
column may be cooled to ambient or sub-ambient temperatures to sharpen 
these peaks.
    10.7  While analysis of the desorbed compounds proceeds, empty the 
purging chamber using the sample introduction syringe. Wash the chamber 
with two 5-mL portions of reagent water. After the purging device has 
been emptied, allow the purge gas to vent through the chamber until the 
frit is dry, so that it is ready for the next sample.
    10.8  After desorbing the sample for four minutes, recondition the 
trap by returning to the purge mode. Wait 15 seconds, then close the 
syringe valve on the purging device to begin gas flow through the trap. 
Maintain the trap temperature at 170-180  deg.C. After approximately 
seven minutes, turn off the trap heater and open the syringe valve to 
stop the gas flow through the trap. When cool, the trap is ready for the 
next sample.

                         11.  System Performance

    11.1  At the beginning of each 8 hr shift during which analyses are 
performed, system calibration and performance shall be verified for all 
pollutants and labeled compounds. For these tests, analysis of the 
aqueous performance standard (Section 6.7.2) shall be used to verify all 
performance criteria. Adjustment and/or recalibration (per Section 7) 
shall be performed until all performance criteria are met. Only after 
all performance criteria are met may blanks and samples be analyzed.
    11.2  BFB spectrum validity--the criteria in table 3 shall be met.
    11.3  Retention times--the absolute retention times of all compounds 
shall approximate those given in Table 2.
    11.4  GC resolution--the valley height between toluene and toluene-
d8 (at m/z 91 and 99 plotted on the same graph) shall be less than 10 
percent of the taller of the two peaks.
    11.5  Calibration verification and on-going precision and accuracy--
compute the concentration of each polutant (Table 1) by isotope dilution 
(Section 7.4) for those compmunds which have labeled analogs. Compute 
the concentration of each pollutant (Table 1) which has no labeled 
analog by the internal standard method (Section 7.5). Compute the 
concentration of the labeled compounds by the internal standard method. 
These concentrations are computed based on the calibration data 
determined in Section 7.
    11.5.1  For each pollutant and labeled compound, compare the 
concentration with the corresponding limit for on-going accuracy in 
Table 5. If all compmunds meet the acceptance criteria, system 
performance is

[[Page 239]]

acceptable and analysis of blanks and samples may continue. If any 
individual value falls outside the range given, system performance is 
unacceptable for that compound.
    Note: The large number of compounds in Table 5 present a substantial 
probability that one or more will fail the acceptance criteria when all 
compounds are analyzed. To determine if the analytical system is out of 
control, or if the failure may be attributed to probability, proceed as 
follows:
    11.5.1.1  Analyze a second aliquot of the aqueous performance 
standard (Section 6.7.2).
    11.5.1.2  Compute the concentration for only those compounds which 
failed the first test (Section 11.5.1). If these compounds now pass, 
system performance is acceptable for all compounds and analyses of 
blanks and samples may proceed. If, however, any of the compounds fail 
again, the measurement system is not performing properly for these 
compounds. In this event, locate and correct the problem or recalibrate 
the system (Section 7), and repeat the entire test (Section 11.1) for 
all compounds.
    11.5.2  Add results which pass the specification in 11.5.1.2 to 
initial (Section 8.2) and previous on-going data. Update QC charts to 
form a graphic representation of laboratory performance (Figure 7). 
Develop a statement of accuracy for each pollutant and labeled compound 
by calculating the average percentage recovery (R) and the standard 
deviation of percent recovery (sr). Express the accuracy as a 
recovery interval from R-2sr to R+2sr. For example, if R=95% 
and sr=5%, the accuracy is 85-105 percent.

12.  Qualitative Determination--Accomplished by Comparison of Data from 
   Analysis of a Sample or Blank with Data from Analysis of the Shift 
 Standard (Section 11.1). Identification is Confirmed When Spectra and 
              Retention Times Agree Per the Criteria Below

    12.1  Labeled compounds and pollutants having no labeled analog:
    12.1.1  The signals for all characteristic masses stored in the 
spectral library (Section 7.2.4) shall be present and shall maximize 
within the same two consecutive scans.
    12.1.2  Either (1) the background corrected EICP areas, or (2) the 
corrected relative intensities of the mass spectral peaks at the GC peak 
maximum shall agree within a factor of two (0.5 to 2 times) for all 
masses stored in the library.
    12.1.3  The retention time relative to the nearest eluted internal 
standard shall be within 7 scans or 20 seconds, 
whichever is greater.
    12.2  Pollutants having a labeled analog:
    12.2.1  The signals for all characteristic masses stored in the 
spectral library (Section 7.2.4) shall be present and shall maximize 
within the same two consecutive scans.
    12.2.2  Either (1) the background corrected EICP areas, or (2) the 
corrected relative intensities of the mass spectral peaks at the GC peak 
maximum shall agree within a factor of two for all masses stored in the 
spectral library.
    12.2.3  The retention time difference between the pollutant and its 
labeled analog shall agree within 2 scans or 6 
seconds (whichever is greater) of this difference in the shift standard 
(Section 11.1).
    12.3  Masses present in the experimental mass spectrum that are not 
present in the reference mass spectrum shall be accounted for by 
contaminant or background ions. If the experimental mass spectrum is 
contaminated, an experienced spectrometrist (Section 1.4) is to 
determine the presence or absence of the compound.

                     13.  Quantitative Determination

    13.1  Isotope dilution--by adding a known amount of a labeled 
compound to every sample prior to purging, correction for recovery of 
the pollutant can be made because the pollutant and its labeled analog 
exhibit the same effects upon purging, desorption, and gas 
chromatography. Relative response (RR) values for sample mixtures are 
used in conjunction with calibration curves described in Section 7.4 to 
determine concentrations directly, so long as labeled compound spiking 
levels are constant. For the toluene example given in Figure 6 (Section 
7.4.3), RR would be equal to 1.174. For this RR value, the toluene 
calibration curve given in Figure 5 indicates a concentration of 31.8 
g/L.
    13.2  Internal standard--calculate the concentration using the 
response factor determined from calibration data (Section 7.5) and the 
following equation:
    Concentration =(As  x  Cis)/(Ais  x  RF) where the 
terms are as defined in Section 7.5.1.
    13.3  If the EICP area at the quantitation mass for any compound 
exceeds the calibration range of the system, the sample is diluted by 
successive factors of 10 and these dilutions are analyzed until the area 
is within the calibration range.
    13.4  Report results for all pollutants and labeled compounds (Table 
1) found in all standards, blanks, and samples, in g/L to three 
significant figures. Results for samples which have been diluted are 
reported at the least dilute level at which the area at the quantitation 
mass is within the calibration range (Section 13.3) and the labeled 
compound recovery is within the normal range for the Method (Section 
14.2).

                    14.  Analysis of Complex Samples

    14.1  Untreated effluents and other samples frequently contain high 
levels (>1000 g/L) of the compounds of interest and of 
interfering compounds. Some samples will foam

[[Page 240]]

excessively when purged; others will overload the trap/or GC column.
    14.2  Dilute 0.5 mL of sample with 4.5 mL of reagent water and 
analyze this diluted sample when labeled compound recovery is outside 
the range given in Table 5. If the recovery remains outside of the range 
for this diluted sample, the aqueous performance standard shall be 
analyzed (Section 11) and calibration verified (Section 11.5). If the 
recovery for the labeled compmund in the aqueous performance standard is 
outside the range given in Table 5, the analytical system is out of 
control. In this case, the instrumelt shall be repaired, the performance 
specifications in Section 11 shall be met, and the analysis of the 
undiluted sample shall be repeated. If the recovery for the aqueous 
performance standard is within the range given in Table 5, the method 
does not work on the sample being analyzed and the result may not be 
reported for regulatory compliance purposes.
    14.3  Reverse search computer programs can misinterpret the spectrum 
of chromatographically unresolved pollutant and labeled compound pairs 
with overlapping spectra when a high level of the pollutant is present. 
Examine each chromatogram for peaks greater than the height of the 
internal standard peaks. These peaks can obscure the compounds of 
interest.

                         15.  Method Performance

    15.1  The specifications for this method were taken from the inter-
laboratory validation of EPA Method 624 (reference 9). Method 1624 has 
been shown to yield slightly better performance on treated effluents 
than Method 624. Additional method performance data can be found in 
Reference 10.

                               References

    1. ``Performance Tests for the Evaluation of Computerized Gas 
Chromatography/Mass Spectrometry Equipment and Laboratories,'' USEPA, 
EMSL/Cincinnati, OH 45268, EPA-600/4-80-025 (April 1980).
    2. Bellar, T.A. and Lichtenberg, J.J., ``Journal American Water 
Works Association,'' 66, 739 (1974).
    3. Bellar, T.A. and Lichtenberg, J.J., ``Semi-automated Headspace 
Analysis of Drinking Waters and Industrial Waters for Purgeable Volatile 
Organic Compounds,'' in Measurement of Organic Pollutants Water and 
Wastewater, C.E. VanHall, ed., American Society for Testing Materials, 
Philadelphia, PA, Special Technical Publication 686, (1978).
    4. ``Working with Carcinogens,'' DHEW, PHS, NIOSH, Publication 77-
206 (1977).
    5. ``OSHA Safety and Health Standards, General Industry,'' 29 CFR 
part 1910, OSHA 2206, (1976).
    6. ``Safety in Academic Chemistry Laboratories,'' American Chemical 
Society Publication, Committee on Chemical Safety (1979).
    7. ``Handbook of Analytical Quality Control in Water and Wastewater 
Laboratories,'' USEPA, EMSL/Cincinnati, OH 45268, EPA-4-79-019 (March 
1979).
    8. ``Methods 330.4 and 330.5 for Total Residual Chlorine,'' USEPA, 
EMSL/Cincinnati, OH 45268, EPA-4-79-020 (March 1979).
    9. ``EPA Method Study 29 EPA Method 624--Purgeables,'' EPA 600/4-84-
054, National Technical Information Service, PB84-209915, Springfield, 
Virginia 22161, June 1984.
    10. ``Colby, B.N., Beimer, R.G., Rushneck, D.R., and Telliard, W.A., 
``Isotope Dilution Gas Chromatography-Mass Spectrometry for the 
Determination of Priority Pollutants in Industrial Effluents,'' USEPA, 
Effluent Guidelines Division, Washington, DC 20460 (1980).

 Table 1--Volatile Organic Compounds Analyzed by Isotope Dilution Gc/MS 
------------------------------------------------------------------------
                                             CAS                        
           Compound             Storet     registry    EPA-EGD    NPDES 
------------------------------------------------------------------------
Acetone......................     81552      67-64-1     516 V  ........
Acrolein.....................     34210     107-02-8     002 V     001 V
Acrylonitrile................     34215     107-13-1     003 V     002 V
Benzene......................     34030      71-43-2     004 V     003 V
Bromodichloromethane.........     32101      75-27-4     048 V     012 V
Bromoform....................     32104      75-25-2     047 V     005 V
Bromomethane.................     34413      74-83-9     046 V     020 V
Carbon tetrachloride.........     32102      56-23-5     006 V     006 V
Chlorobenzene................     34301     108-90-7     007 V     007 V
Chloroethane.................     34311      75-00-3     016 V     009 V
2-chloroethylvinyl ether.....     34576     110-75-8     019 V     010 V
Chloroform...................     32106      67-66-1     023 V     011 V
Chloromethane................     34418      74-87-3     045 V     021 V
Dibromochloromethane.........     32105     124-48-1     051 V     008 V
1,1-dichloroethane...........     34496      75-34-3     013 V     014 V
1,2-dichloroethane...........     34536     107-06-2     010 V     015 V
1,1-dichloroethene...........     34501      75-35-4     029 V     016 V
Trans-1,2-dichloroethane.....     34546     156-60-5     030 V     026 V
1,2-dichloropropane..........     34541      78-87-5     032 V     017 V
Cis-1,3-dichloropropene......     34704   10061-01-5  ........  ........

[[Page 241]]

                                                                        
Trans-1,3-dichloropropene....     34699   10061-02-6     033 V  ........
Diethyl ether................     81576      60-29-7     515 V  ........
P-dioxane....................     81582     123-91-1     527 V  ........
Ethylbenzene.................     34371     100-41-4     038 V     019 V
Methylene chloride...........     34423      75-09-2     044 V     022 V
Methyl ethyl ketone..........     81595      78-93-3     514 V  ........
1,1,2,2-tetrachloroethane....     34516      79-34-5     015 V     023 V
Tetrachlorethene.............     34475     127-18-4     085 V     024 V
Toluene......................     34010     108-88-3     086 V     025 V
1,1,1-trichloroethane........     34506      71-55-6     011 V     027 V
1,1,2-trichloroethane........     34511      79-00-5     014 V     028 V
Trichloroethene..............     39180      79-01-6     087 V     029 V
Vinyl chloride...............     39175      75-01-4     088 V     031 V
------------------------------------------------------------------------


  Table 2--Gas Chromatography of Purgeable Organic Compounds by Isotope 
                             Dilution GC/MS                             
------------------------------------------------------------------------
                                                    Mean       Minimum  
EGD                                         Ref  retention    level (2) 
No.                 Compound                EGD     time    (g/
(1)                                         No.    (sec)         L)     
------------------------------------------------------------------------
181  Bromochloromethane (I.S.)............  181      730           10   
245  Chloromethane-d3.....................  181      147           50   
345  Chloromethane........................  245      148           50   
246  Bromomethane-d3......................  181      243           50   
346  Bromomethane.........................  246      246           50   
288  Vinyl chloride-d3....................  181      301           50   
388  Vinyl chloride.......................  288      304           10   
216  Chloroethane-d5......................  181      378           50   
316  Chloroethane.........................  216      386           50   
244  Methylene chloride-d2................  181      512           10   
344  Methylene chloride...................  244      517           10   
616  Acetone-d6...........................  181      554           50   
716  Acetone..............................  616      565           50   
002  Acrolein.............................  181      566           50   
203  Acrylonitrile-d3.....................  181      606           50   
303  Acrylonitrile........................  203      612           50   
229  1,1-dichloroethene-d2................  181      696           10   
329  1,1-dichloroethene...................  229      696           10   
213  1,1-dichloroethane-d3................  181      778           10   
313  1,1-dichloroethane...................  213      786           10   
615  Diethyl ether-d10....................  181      804           50   
715  Diethyl ether........................  615      820           50   
230  Trans-1,2-dichloroethene-d2..........  181      821           10   
330  Trans-1,2-dichloroethene.............  230      821           10   
614  Methyl ethyl ketone-d3...............  181      840           50   
714  Methyl ethyl ketone..................  614      848           50   
223  Chloroform-13C1......................  181      861           10   
323  Chloroform...........................  223      861           10   
210  1,2-dichloroethane-d4................  181      901           10   
310  1,2-dichloroethane...................  210      910           10   
211  1,1,1-trichloroethane-13C2...........  181      989           10   
311  1,1,1-trichloroethane................  211      999           10   
527  p-dioxane............................  181     1001           10   
206  Carbon tetrachloride-13C1............  182     1018           10   
306  Carbon tetrachloride.................  206     1018           10   
248  Bromodichloromethane-13C1............  182     1045           10   
348  Bromodichloromethane.................  248     1045           10   
232  1,2-dichloropropane-d6...............  182     1123           10   
332  1.2-dichloropropane..................  232     1134           10   
233  Trans-1,3-dichloropropene-d4.........  182     1138           10   
333  Trans-1,3-dichloropropene............  233     1138           10   
287  Trichloroethene-13C1.................  182     1172           10   
387  Trichloroethene......................  287     1187           10   
204  Benzene-d6...........................  182     1200           10   
304  Benzene..............................  204     1212           10   
251  Chlorodibromemethane-13C1............  182     1222           10   
351  Chlorodibromomethane.................  251     1222           10   
214  1,1,2-trichloroethane-13C2...........  182     1224           10   
314  1,1,2-trichloroethane................  214     1224           10   
019  2-chloroethylvinyl ether.............  182     1278           10   
182  2-bromo-1-chloropropane (I.S.).......  182     1306           10   
247  Bromoform-13C1.......................  182     1386           10   
347  Bromoform............................  247     1386           10   
215  1,1,2,2-tetrachloroethane-d2.........  183     1525           10   
315  1,1,2,2-tetrachloroethane............  215     1525           10   
285  Tetrachloroethene-13C2...............  183     1528           10   
385  Tetrachloroethene....................  285     1528           10   
183  1,4-dichlorobutale (int std).........  183     1555           10   
286  Toluene-d8...........................  183     1603           10   
386  Toluene..............................  286     1619           10   
207  Chlorobenzene-d5.....................  183     1679           10   
307  Chlorobenzene........................  207     1679           10   
238  Ethylbenzene-d10.....................  183     1802           10   
338  Ethylbenzene.........................  238     1820           10   
185  Bromofluorobenzene...................  183     1985           10   
------------------------------------------------------------------------
(1) Reference numbers beginning with 0, 1 or 5 indicate a pollutant     
  quantified by the internal standard method; reference numbers         
  beginning with 2 or 6 indicate a labeled compound quantified by the   
  internal standard method; reference numbers beginning with 3 or 7     
  indicate a pollutant quantified by isotope dilution.                  
(2) This is a minimum level at which the analytical system shall give   
  recognizable mass spectra (background corrected) and acceptable       
  calibration points. Column: 2.4m (8 ft) x 2 mm i.d. glass, packed with
  one percent SP-1000 coated on 60/80 Carbopak B. Carrier gas: helium at
  40 mL/min. Temperature program: 3 min at 45 C, 8 C per min to 240 C,  
  hold at 240 C for 15 minutes.                                         
                                                                        
Note: The specifications in this table were developed from data         
  collected from three wastewater laboratories.                         


               Table 3--BFB Mass-Intensity Specifications               
------------------------------------------------------------------------
 Mass                          Intensity required                       
------------------------------------------------------------------------
50...  15 to 40 percent of mass 95.                                     
75...  30 to 60 percent of mass 95.                                     
95...  base peak, 100 percent.                                          
96...  5 to 9 percent of mass 95.                                       
173..  <2 percent of mass 174.                                          
174..  >50 percent of mass 95.                                          
175..  5 to 9 percent of mass 174                                       
176..  95 to 101 percent of mass 174                                    

[[Page 242]]

                                                                        
177..  5 to 9 percent of mass 176.                                      
------------------------------------------------------------------------


        Table 4--Volatile Organic Compound Characteristic Masses        
------------------------------------------------------------------------
                                                              Primary m/
                  Labeled compound                    Analog      z's   
------------------------------------------------------------------------
Acetone............................................       d6       58/64
Acrolein...........................................       d2       56/58
Acrylonitrile......................................       d3       53/56
Benzene............................................       d6       78/84
Bromodichloromethane...............................      13C       83/86
Bromoform..........................................      13C     173/176
Bromomethale.......................................       d3       96/99
Carbon tetrachloride...............................      13C       47/48
Chlorobenzene......................................       d5     112/117
Chloroethane.......................................       d5       64/71
2-chloroethylvinyl ether...........................       d7     106/113
Chloroform.........................................      13C       85/86
Chloromethane......................................       d3       50/53
Dibromochloromethane...............................      13C     129/130
1,1-dichloroethane.................................       d3       63/66
1,2-dichloroethane.................................       d4       62/67
1,1-dichloroethene.................................       d2       61/65
Trans-1,2-dichloroethene...........................       d2       61/65
1,2-dichloropropane................................       d6       63/67
Cis-1,3-dichloropropene............................       d4       75/79
Trans-1,3-dichloropropene..........................       d4       75/79
Diethyl ether......................................      d10       74/84
p-dioxane..........................................       d8       88/96
Ethylbenzene.......................................      d10     106/116
Methylene chloride.................................       d2       84/88
Methyl ethyl ketone................................       d3       72/75
1,1,2,2-tetrachloroethane..........................       d2       83/84
Tetrachloroethene..................................     13C2     166/172
Toluene............................................       d8       92/99
1,1,1-trichloroethane..............................       d3      97/102
1,1,2-trichloroethane..............................     13C2       83/84
Trichloroethene....................................      13C      95/133
Vinyl chloride.....................................       d3       62/65
------------------------------------------------------------------------


                               Table 5--Acceptance Criteria for Performance Tests                               
----------------------------------------------------------------------------------------------------------------
                                                                  Acceptance criteria at 20 g/L        
                                                        --------------------------------------------------------
                                                             Initial precision and       Labeled      On-going  
                                                            accuracy section 8.2.3       compound     accuracy  
                        Compound                        ------------------------------   recovery     sec. 11.5 
                                                                                         sec. 8.3  -------------
                                                          s (g/    and 14.2    R (g/L)           L)       -------------    m>g/L)   
                                                                                       P (percent)              
----------------------------------------------------------------------------------------------------------------
Acetone................................................                           Note 1                        
Acrolein...............................................                           Note 2                        
Acrylonitrile..........................................                           Note 2                        
Benzene................................................           9.0       13.0-28.2       ns-196          4-33
Bromodichloromethane...................................           8.2        6.5-31.5       ns-199          4-34
Bromoform..............................................           7.0        7.4-35.1       ns-214          6-36
Bromomethane...........................................          25.0          d-54.3       ns-414          d-61
Carbon tetrachloride...................................           6.9       15.9-24.8       42-165         12-30
Chlorobenzene..........................................           8.2       14.2-29.6       ns-205          4-35
Chloroethane...........................................          14.8        2.1-46.7       ns-308          d-51
2-chloroethylvinyl ether...............................          36.0          d-69.8       ns-554          d-79
Chloroform.............................................           7.9       11.6-26.3       18-172          8-30
Chloromethane..........................................          26.0          d-55.5       ns-410          d-64
Dibromochloromethane...................................           7.9       11.2-29.1       16-185          8-32
1,1-dichloroethane.....................................           6.7       11.4-31.4       23-191          9-33
1,2-dichloroethane.....................................           7.7       11.6-30.1       12-192          8-33
1,1-dichloroethene.....................................          11.7          d-49.8       ns-315          d-52
Trans-1,2-dichloroethene...............................           7.4       10.5-31.5       15-195          8-34
1,2-dichloropropane....................................          19.2          d-46.8       ns-343          d-51
Cis-1,3-dichloropropene................................          22.1          d-51.0       ns-381          d-56
Trans-1,3-dichloropropene..............................          14.5          d-40.2       ns-284          d-44
Diethyl ether..........................................                           Note 1                        
P-dioxane..............................................                           Note 1                        
Ethyl benzene..........................................           9.6       15.6-28.5       ns-203          5-35
Methylene chloride.....................................           9.7          d-49.8       ns-316          d-50
Methyl ethyl ketone....................................                           note 1                        
1,1,2,2-tetrachloroethane..............................           9.6       10.7-30.0        5-199          7-34
Tetrachloroethene......................................           6.6       15.1-28.5       31-181         11-32
Toluene................................................           6.3       14.5-28.7        4-193          6-33
1,1,1-trichloroethane..................................           5.9       10.5-33.4       12-200          8-35
1,1,2-trichloroethane..................................           7.1       11.8-29.7       21-184          9-32
Trichloroethene........................................           8.9       16.6-29.5       35-196         12-34
Vinyl chloride.........................................          27.9          d-58.5       ns-452          d-65
----------------------------------------------------------------------------------------------------------------
d=detected; result must be greater than zero.                                                                   
ns=no specification; limit would be below detection limit.                                                      
                                                                                                                
Note 1: Specifications not available for these compounds at time of release of this method.                     
Note 2: Specifications not developed for these compounds; use method 603.                                       


[[Page 243]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.055


[[Page 244]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.056


[[Page 245]]

   Method 1625 Revision B--Semivolatile Organic Compounds by Isotope 
                             Dilution GC/MS

                        1.  Scope and Application

    1.1  This method is designed to determine the semivolatile toxic 
organic pollutants associated with the 1976 Consent Decree and 
additional compounds amenable to extraction and analysis by capillary 
column gas chromatography-mass spectrometry (GC/MS).
    1.2  The chemical compounds listed in Tables 1 and 2 may be 
determined in municipal and industrial discharges by this method. The 
method is designed to meet the survey requirements of Effluent 
Guidelines Division (EGD) and the National Pollutants Discharge 
Elimination System (NPDES) under 40 CFR 136.1. Any modifications of this 
method, beyond those expressly permitted, shall be considered as major 
modifications subject to application and approval of alternate test 
procedures under 40 CFR 136.4 and 136.5.
    1.3  The detection limit of this method is usually dependent on the 
level of interferences rather than instrumental limitations. The limits 
listed in Tables 3 and 4 represent the minimum quantity that can be 
detected with no interferences present.
    1.4  The GC/MS portions of this method are for use only by analysts 
experienced with GC/MS or under the close supervision of such qualified 
persons. Laboratories unfamiliar with analyses of environmental samples 
by GC/MS should run the performance tests in reference 1 before 
beginning.

                          2.  Summary of Method

    2.1  Stable isotopically labeled analogs of the compounds of 
interest are added to a one liter wastewater sample. The sample is 
extracted at pH 12-13, then at pH <2 with methylene chloride using 
continuous extraction techniques. The extract is dried over sodium 
sulfate and concentrated to a volume of one mL. An internal standard is 
added to the extract, and the extract is injected into the gas 
chromatograph (GC). The compounds are separated by GC and detected by a 
mass spectrometer (MS). The labeled compounds serve to correct the 
variability of the analytical technique.
    2.2  Identification of a compound (qualitative analysis) is 
performed by comparing the GC retention time and background corrected 
characteristic spectral masses with those of authentic standards.
    2.3  Quantitative analysis is performed by GC/MS using extracted ion 
current profile (EICP) areas. Isotope dilution is used when labeled 
compounds are available; otherwise, an internal standard method is used.
    2.4  Quality is assured through reproducible calibration and testing 
of the extraction and GC/MS systems.

                   3.  Contamination and Interferences

    3.1  Solvents, reagents, glassware, and other sample processing 
hardware may yield artifacts and/or elevated baselines causing 
misinterpretation of chromatograms and spectra. All materials shall be 
demonstrated to be free from interferences under the conditions of 
analysis by running method blanks initially and with each sample lot 
(samples started through the extraction process on a given 8 hr shift, 
to a maximum of 20). Specific selection of reagents and purification of 
solvents by distillation in all-glass systems may be required. Glassware 
and, where possible, reagents are cleaned by solvent rinse and baking at 
450  deg.C for one hour minimum.
    3.2  Interferences coextracted from samples will vary considerably 
from source to source, depending on the diversity of the industrial 
complex or municipality being samples.

                               4.  Safety

    4.1  The toxicity or carcinogenicity of each compound or reagent 
used in this method has not been precisely determined; however, each 
chemical compound should be treated as a potential health hazard. 
Exposure to these compounds should be reduced to the lowest possible 
level. The laboratory is responsible for maintaining a current awareness 
file of OSHA regulations regarding the safe handling of the chemicals 
specified in this method. A reference file of data handling sheets 
should also be made available to all personnel involved in these 
analyses. Additional information on laboratory safety can be found in 
references 2-4.
    4.2  The following compounds covered by this method have been 
tentatively classified as known or suspected human or mammalian 
carcinogens: benzidine benzo(a)anthracene, 3,3'-dichlorobenzidine, 
benzo(a)pyrene, dibenzo(a,h)anthracene, N-nitrosodimethylamine, and 
-naphtylamine. Primary standards of these compounds shall be 
prepared in a hood, and a NIOSH/MESA approved toxic gas respirator 
should be worn when high concentrations are handled.

                       5.  Apparatus and Materials

    5.1  Sampling equipment for discrete or composite sampling.
    5.1.1  Sample bottle, amber glass, 1.1 liters minimum. If amber 
bottles are not available, samples shall be protected from light. 
Bottles are detergent water washed, then solvent rinsed or baked at 450 
deg.C for one hour minimum before use.
    5.1.2  Bottle caps--threaded to fit sample bottles. Caps are lined 
with Teflon. Aluminum foil may be substituted if the sample is not 
corrosive. Liners are detergent water washed, then reagent water 
(Section 6.5) and solvent rinsed, and baked at approximately 200  deg.C 
for one hour minimum before use.

[[Page 246]]

    5.1.3  Compositing equipment--automatic or manual compositing system 
incorporating glass containers for collection of a minimum 1.1 liters. 
Sample containers are kept at 0 to 4  deg.C during sampling. Glass or 
Teflon tubing only shall be used. If the sampler uses a peristaltic 
pump, a minimum length of compressible silicone rubber tubing may be 
used in the pump only. Before use, the tubing is thoroughly rinsed with 
methanol, followed by repeated rinsings with reagent water (Section 6.5) 
to minimize sample contamination. An integrating flow meter is used to 
collect proportional composite samples.
    5.2  Continuous liquid-liquid extractor--Teflon or glass conncecting 
joints and stopcocks without lubrication (Hershberg-Wolf Extractor) one 
liter capacity, Ace Glass 6841-10, or equivalent.
    5.3  Drying column--15 to 20 mm i.d. Pyrex chromatographic column 
equipped with coarse glass frit or glass wool plug.
    5.4  Kuderna-Danish (K-D) apparatus
    5.4.1  Concentrator tube--10mL, graduated (Kontes K-570050-1025, or 
equivalent) with calibration verified. Ground glass stopper (size 19/22 
joint) is used to prevent evaporation of extracts.
    5.4.2  Evaporation flask--500 mL (Kontes K-570001-0500, or 
equivalent), attached to concentrator tube with springs (Kontes K-
662750-0012).
    5.4.3  Snyder column--three ball macro (Kontes K-503000-0232, or 
equivalent).
    5.4.4  Snyder column--two ball micro (Kontes K-469002-0219, or 
equivalent).
    5.4.5  Boiling chips--approx 10/40 mesh, extracted with methylene 
chloride and baked at 450  deg.C for one hr minimum.
    5.5  Water bath--heated, with concentric ring cover, capable of 
temperature control 2  deg.C, installed in a fume hood.
    5.6  Sample vials--amber glass, 2-5 mL with Teflon-lined screw cap.
    5.7  Analytical balance--capable of weighing 0.1 mg.
    5.8  Gas chromatograph--shall have splitless or on-column injection 
port for capillary column, temperature program with 30  deg.C hold, and 
shall meet all of the performance specifications in Section 12.
    5.8.1  Column--305 m x 0.250.02 mm i.d. 5% 
phenyl, 94% methyl, 1% vinyl silicone bonded phase fused silica 
capillary column (J & W DB-5, or equivalent).
    5.9  Mass spectrometer--70 eV electron impact ionization, shall 
repetitively scan from 35 to 450 amu in 0.95 to 1.00 second, and shall 
produce a unit resolution (valleys between m/z 441-442 less than 10 
percent of the height of the 441 peak), backgound corrected mass 
spectrum from 50 ng decafluorotriphenylphosphine (DFTPP) introduced 
through the GC inlet. The spectrum shall meet the mass-intensity 
criteria in Table 5 (reference 5). The mass spectrometer shall be 
interfaced to the GC such that the end of the capillary column 
terminates within one centimeter of the ion source but does not 
intercept the electron or ion beams. All portions of the column which 
connect the GC to the ion source shall remain at or above the column 
temperature during analysis to preclude condensation of less volatile 
compounds.
    5.10  Data system--shall collect and record MS data, store mass-
intensity data in spectral libraries, process GC/MS data, generate 
reports, and shall compute and record response factors.
    5.10.1  Data acquisition--mass spectra shall be collected 
continuously throughout the analysis and stored on a mass storage 
device.
    5.10.2  Mass spectral libraries--user created libraries containing 
mass spectra obtained from analysis of authentic standards shall be 
employed to reverse search GC/MS runs for the compounds of interest 
(Section 7.2).
    5.10.3  Data processing--the data system shall be used to search, 
locate, identify, and quantify the compounds of interest in each GC/MS 
analysis. Software routines shall be employed to compute retention times 
and peak areas. Displays of spectra, mass chromatograms, and library 
comparisons are required to verify results.
    5.10.4  Response factors and multipoint calibrations--the data 
system shall be used to record and maintain lists of response factors 
(response ratios for isotope dilution) and multipoint calibration curves 
(Section 7). Computations of relative standard deviation (coefficient of 
variation) are useful for testing calibration linearity. Statistics on 
initial (Section 8.2) and on-going (Section 12.7) performance shall be 
computed and maintained.

                       6.  Reagents and Standards

    6.1  Sodium hydroxide--reagent grade, 6N in reagent water.
    6.2  Sulfuric acid--reagent grade, 6N in reagent water.
    6.3  Sodium sulfate--reagent grade, granular anhydrous, rinsed with 
methylene chloride (20 mL/g) and conditioned at 450  deg.C for one hour 
minimum.
    6.4  Methylene chloride--distilled in glass (Burdick and Jackson, or 
equivalent).
    6.5  Reagent water--water in which the compounds of interest and 
interfering compounds are not detected by this method.
    6.6  Standard solutions--purchased as solutions or mixtures with 
certification to their purity, concentration, and authenticity, or 
prepared from materials of known purity and composition. If compound 
purity is 96 percent or greater, the weight may be used without 
correction to compute the concentration of the standard. When not being 
used, standards are stored in the dark at -20 to -10  deg.C in screw-
capped vials with Teflon-lined lids. A mark is placed on the vial at the

[[Page 247]]

level of the solution so that solvent evaporation loss can be detected. 
The vials are brought to room temperature prior to use. Any precipitate 
is redissolved and solvent is added if solvent loss has occurred.
    6.7  Preparation of stock solutions--prepare in methylene chloride, 
benzene, p-dioxane, or a mixture of these solvents per the steps below. 
Observe the safety precautions in Section 4. The large number of labeled 
and unlabeled acid, base/neutral, and Appendix C compounds used for 
combined calibration (Section 7) and calibration verification (12.5) 
require high concentratimns (approx 40 mg/mL) when individual stock 
solutions are prepared, so that dilutions of mixtures will permit 
calibration with all compounds in a single set of solutions. The working 
range for most compounds is 10-200 g/mL. Compounds with a 
reduced MS response may be prepared at higher concentrations.
    6.7.1  Dissolve an appropriate amount of assayed reference material 
in a suitable solvent. For example, weigh 400 mg naphthalene in a 10 mL 
ground glass stoppered volumetric flask and fill to the mark with 
benzene. After the naphthalene is completely dissolved, transfer the 
solution to a 15 mL vial with Teflon-lined cap.
    6.7.2  Stock standard solutions should be checked for signs of 
degradation prior to the preparation of calibration or performance test 
standards. Quality control check samples that can be used to determine 
the accuracy of calibration standards are available from the US 
Environmental Protection Agency, Environmental Monitoring and Support 
Laboratory, Cincinnati, Ohio 45268.
    6.7.3  Stock standard solutions shall be replaced after six months, 
or sooner if comparison with quality control check samples indicates a 
change in concentration.
    6.8  Labeled compound spiking solution--from stock standard 
solutions prepared as above, or from mixtures, prepare the spiking 
solution at a concentration of 200 g/mL, or at a concentration 
appropriate to the MS response of each compound.
    6.9  Secondary standard--using stock solutions (Section 6.7), 
prepare a secondary standard containing all of the compounds in Tables 1 
and 2 at a concentration of 400 g/mL, or higher concentration 
appropriate to the MS response of the compound.
    6.10  Internal standard solution--prepare 2,2'-difluorobiphenyl 
(DFB) at a concentration of 10 mg/mL in benzene.
    6.11  DFTPP solution--prepare at 50 g/mL in acetone.
    6.12  Solutions for obtaining authentic mass spectra (Section 7.2)--
prepare mixtures of compounds at concentrations which will assure 
authentic spectra are obtained for storage in libraries.
    6.13  Calibration solutions--combine 0.5 mL of the solution in 
Section 6.8 with 25, 50, 125, 250, and 500 uL of the solution in section 
6.9 and bring to 1.00 mL total volume each. This will produce 
calibration solutions of nominal 10, 20, 50, 100, and 200 g/mL 
of the pollutants and a constant nominal 100 g/mL of the 
labeled compounds. Spike each solution with 10 L of the 
internal standard solution (Section 6.10). These solutions permit the 
relative response (labeled to unlabeled) to be measured as a function of 
concentration (Section 7.4).
    6.14  Precision and recovery standard--used for determination of 
initial (Section 8.2) and on-going (Section 12.7) precision and 
recovery. This solution shall contain the pollutants and labeled 
compounds at a nominal concentration of 100 g/mL.
    6.15  Stability of solutions--all standard solutions (Sections 6.8-
6.14) shall be analyzed within 48 hours of preparation and on a monthly 
basis thereafter for signs of degradation. Standards will remain 
acceptable if the peak area at the quantitation mass relative to the DFB 
internal standard remains within 15 percent of the area 
obtained in the initial analysis of the standard.

                             7.  Calibration

    7.1  Assemble the GC/MS and establish the operating conditions in 
Table 3. Analyze standards per the procedure in Section 11 to 
demonstrate that the analytical system meets the detection limits in 
Tables 3 and 4, and the mass-intensity criteria in Table 5 for 50 ng 
DFTPP.
    7.2  Mass spectral libraries--detection and identification of 
compounds of interest are dependent upon spectra stored in user created 
libraries.
    7.2.1  Obtain a mass spectrum of each pollutant, labeled compound, 
and the internal standard by analyzing an authentic standard either 
singly or as part of a mixture in which there is no interference between 
closely eluted components. That only a single compound is present is 
determined by examination of the spectrum. Fragments not attributable to 
the compound under study indicate the presence of an interfering 
compound.
    7.2.2  Adjust the analytical conditions and scan rate (for this test 
only) to produce an undistorted spectrum at the GC peak maximum. An 
undistorted spectrum will usually be obtained if five complete spectra 
are collected across the upper half of the GC peak. Software algorithms 
designed to ``enhance'' the spectrum may eliminate distortion, but may 
also eliminate authentic masses or introduce other distortion.
    7.2.3  The authentic reference spectrum is obtained under DFTPP 
tuning conditions (Section 7.1 and Table 5) to normalize it to spectra 
from other instruments.
    7.2.4  The spectrum is edited by saving the 5 most intense mass 
spectral peaks and all other mass spectral peaks greater than 10

[[Page 248]]

percent of the base peak. This edited spectrum is stored for reverse 
search and for compound confirmation.
    7.3  Analytical range--demonstrate that 20 ng anthracene or 
phenanthrene produces an area at m/z 178 approx one-tenth that required 
to exceed the linear range of the system. The exact value must be 
determined by experience for each instrument. It is used to match the 
calibration range of the instrument to the analytical range and 
detection limits required, and to diagnose instrument sensitivity 
problems (Section 15.4). The 20 ug/mL calibration standard (Section 
6.13) can be used to demonstrate this performance.
    7.3.1  Polar compound detection--demonstrate that unlabeled 
pentachlorophenol and benzidine are detectable at the 50 g/mL 
level (per all criteria in Section 13). The 50 g/mL calibration 
standard (Section 6.13) can be used to demonstrate this performance.
    7.4  Calibration with isotope dilution--isotope dilution is used 
when (1) labeled compounds are available, (2) interferences do not 
preclude its use, and (3) the quantitation mass extracted ion current 
profile (EICP) area for the compound is in the calibration range. If any 
of these conditions preclude isotope dilution, internal standard methods 
(Section 7.5 or 7.6) are used.
    7.4.1  A calibration curve encompassing the concentration range is 
prepared for each compound to be determined. The relative response 
(pollutant to labeled) vs concentration in standard solutions is plotted 
or computed using a linear regression. The example in Figure 1 shows a 
calibration curve for phenol using phenol-d5 as the isotopic diluent. 
Also shown are the  10 percent error limits (dotted lines). 
Relative Reponse (RR) is determined according to the procedures 
described below. A minimum of five data points are employed for 
calibration.
    7.4.2  The relative response of a pollutant to its labeled analog is 
determined from isotope ratio values computed from acquired data. Three 
isotope ratios are used in this process:

    Rx = the isotope ratio measured for the pure pollutant.
    Ry = the isotope ratio measured for the labeled compound.
    Rm = the isotope ratio of an analytical mixture of pollutant 
and labeled compounds.

    The m/z's are selected such that Rx>Ry. If Rm is not 
between 2Ry and 0.5Rx, the method does not apply and the 
sample is analyzed by internal or external standard methods.
    7.4.3  Capillary columns usually separate the pollutant-labeled 
pair, with the labeled compound eluted first (Figure 2). For this case, 
Rx = [area m1/z]/1, at the retention time of the pollutant 
(RT2). Ry = 1/[area m2/z, at the retention time of the 
labeled compound RT1). Rm = [area at m1/z (at RT2)]/
[area at RT1)], as measured in the mixture of the pollutant and 
labeled compounds (Figure 2), and RR = Rm.
    7.4.4  Special precautions are taken when the pollutant-labeled pair 
is not separated, or when another labeled compound with interfering 
spectral masses overlaps the pollutant (a case which can occur with 
isomeric compounds). In this case, it is necessary to determine the 
respective contributions of the pollutant and labeled compounds to the 
respective EICP areas. If the peaks are separated well enough to permit 
the data system or operator to remove the contributions of the compounds 
to each other, the equations in Section 7.4.3 apply. This usually occurs 
when the height of the valley between the two GC peaks at the same m/z 
is less than 10 percent of the height of the shorter of the two peaks. 
If significant GC and spectral overlap occur, RR is computed using the 
following equation:

    RR = (Ry - Rm) (Rx + 1)/(Rm - Rx) (Ry 
+ 1), where Rx is measured as shown in Figure 3A, Ry is 
measured as shown in Figure 3B, and Rm is measured as shown in 
Figure 3C. For example, Rx = 46100/4780 = 9.644, Ry = 2650/
43600 = 0.0608, Rm = 49200/48300 = 1.019. amd RR = 1.114.

    7.4.5  To calibrate the analytical system by isotope dilution, 
analyze a 1.0 L aliquot of each of the calibration standards 
(Section 6.13) using the procedure in Section 11. Compute the RR at each 
concentration.
    7.4.6  Linearity--if the ratio of relative response to concentration 
for any compound is constant (less than 20 percent coefficient of 
variation) over the 5 point calibration range, and averaged relative 
response/concentration ratio may be used for that compound; otherwise, 
the complete calibration curve for that compound shall be used over the 
5 point calibration range.
    7.5  Calibration by internal standard--used when criteria for istope 
dilution (Section 7.4) cannot be met. The internal standard to be used 
for both acid and base/neutral analyses is 2,2'-difluorobiphenyl. The 
internal standard method is also applied to determination of compounds 
having no labeled analog, and to measurement of labeled compounds for 
intra-laboratory statistics (Sections 8.4 and 12.7.4).
    7.5.1  Response factors--calibration requires the determination of 
response factors (RF) which are defined by the following equation:

    RF = (As  x  Cis)/(Ais  x  Cs), where
    As is the area of the characteristic mass for the compmund in 
the daily standard
    Ais is the area of the characteristic mass for the internal 
standard
    Cis is the concentration of the internal standard (g/
mL)
    Cs is the concentration of the compound in the daily standard 
(g/mL)


[[Page 249]]


    7.5.1.1  The response factor is determined for at least five 
concentrations appropriate to the response of each compound (Section 
6.13); nominally, 10, 20, 50, 100, and 200 g/mL. The amount of 
internal standard added to each extract is the same (100 g/mL) 
so that Cis remains constant. The RF is plotted vs concentration 
for each compound in the standard (Cs) to produce a calibration 
curve.
    7.5.1.2  Linearity--if the response factor (RF) for any compound is 
constant (less than 35 percent coefficient of variation) over the 5 
point calibration range, an averaged response factor may be used for 
that compound; otherwise, the complete calibration curve for that 
compound shall be used over the 5 point range.
    7.6  Combined calibration--by using calibration solutions (Section 
6.13) containing the pollutants, labeled compounds, and the internal 
standard, a single set of analyses can be used to produce calibration 
curves for the isotope dilution and internal standard methods. These 
curves are verified each shift (Section 12.5) by analyzing the 100 
g/mL calibration standard (Section 6.13). Recalibration is 
required only if calibration verification (Section 12.5) criteria cannot 
be met.

                  8.  Quality Assurance/Quality Control

    8.1  Each laboratory that uses this method is required to operate a 
formal quality assurance program. The minimum requirements of this 
program consist of an initial demonstration of laboratory capability, 
analysis of samples spiked with labeled compounds to evaluate and 
document data quality, and analysis of standards and blanks as tests of 
continued performance. Laboratory performance is compared to established 
performance criteria to determine if the results of analyses meet the 
performance characteristics of the method.
    8.1.1  The analyst shall make an initial demonstration of the 
ability to generate acceptable accuracy and precision with this method. 
This ability is established as described in Section 8.2.
    8.1.2  The analyst is permitted to modify this method to improve 
separations or lower the costs of measurements, provided all performance 
specifications are met. Each time a modification is made to the method, 
the analyst is required to repeat the procedure in Section 8.2 to 
demonstrate method performance.
    8.1.3  Analyses of blanks are required to demonstrate freedom from 
contamination. The procedures and criteria for analysis of a blank are 
described in Section 8.5.
    8.1.4  The laboratory shall spike all samples with labeled compounds 
to monitor method performance. This test is described in Section 8.3. 
When results of these spikes indicate atypical method performance for 
samples, the samples are diluted to bring method performance within 
acceptable limits (Section 15).
    8.1.5  The laboratory shall, on an on-going basis, demonstrate 
through calibration verification and the analysis of the precision and 
recovery standard (Section 6.14) that the analysis system is in control. 
These procedures are described in Sections 12.1, 12.5, and 12.7.
    8.1.6  The laboratory shall maintain records to define the quality 
of data that is generated. Development of accuracy statements is 
described in Section 8.4.
    8.2  Initial precision and accuracy--to establish the ability to 
generate acceptable precision and accuracy, the analyst shall perform 
the following operations:
    8.2.1  Extract, concentrate, and analyze two sets of four one-liter 
aliquots (8 aliquots total) of the precision and recovery standard 
(Section 6.14) according to the procedure in Section 10.
    8.2.2  Using results of the first set of four analyses, compute the 
average recovery (X) in g/mL and the standard deviation of the 
recovery (s) in g/L for each compound, by isotope 
dilution for pollutants with a labeled analog, and by internal standard 
for labeled compounds and pollutants with no labeled analog.
    8.2.3  For each compound, compare s and X with the corresponding 
limits for initial precision and accuracy in Table 8. If s and X for all 
compounds meet the acceptance criteria, system performance is acceptable 
and analysis of blanks and samples may begin. If, however, any 
individual s exceeds the precision limit or any individual X falls 
outside the range for accuracy, system performance is unacceptable for 
that compound.

    Note: The large number of compounds in Table 8 present a substantial 
probability that one or more will fail the acceptance criteria when all 
compounds are analyzed. To determine if the analytical system is out of 
control, or if the failure can be attributed to probability, proceed as 
follows:

    8.2.4  Using the results of the second set of four analyses, compute 
s and X for only those compounds which failed the test of the first set 
of four analyses (Section 8.2.3). If these compounds now pass, system 
performance is acceptable for all compounds and analysis of blanks and 
samples may begin. If, however, any of the same compoulds fail again, 
the analysis system is not performing properly for these compounds. In 
this event, correct the problem and repeat the entire test (Section 
8.2.1).
    8.3  The laboratory shall spike all samples with labeled compounds 
to assess method performance on the sample matrix.
    8.3.1  Analyze each sample according to the method in Section 10.

[[Page 250]]

    8.3.2  Compute the percent recovery (P) of the labeled compounds 
using the internal standard methmd (Section 7.5).
    8.3.3  Compare the labeled compound recovery for each compound with 
the corresponding limits in Table 8. If the recovery of any compounds 
falls outside its warning limit, method performance is unacceptable for 
that compound in that sample, Therefore, the sample is complex and is to 
be diluted and reanalyzed per Section 15.4.
    8.4  As part of the QA program for the laboratory, method accuracy 
for wastewater samples shall be assessed and records shall be 
maintained. After the analysis of five wastewater samples for which the 
labeled compounds pass the tests in Section 8.3, compute the average 
percent recovery (P) and the standard deviation of the percent recovery 
(sp) for the labeled compounds only. Express the accuracy 
assessment as a percent recovery interval from P--2 sp to 
P+2sp. For example, if P=90% and sp=10%, the accuracy interval 
is expressed as 70-100%. Update the accuracy assessment for each 
compound on a regular basis (e.g. after each 5-10 new accuracy 
measurements).
    8.5  Blanks--reagent water blanks are analyzed to demonstrate 
freedom from contamination.
    8.5.1  Extract and concentrate a blank with each sample lot (samples 
started through the extraction process on the same 8 hr shift, to a 
maximum of 20 samples). Analyze the blank immediately after analysis of 
the precision and recovery standard (Section 6.14) to demonstrate 
freedom from contamination.
    8.5.2  If any of the compounds of interest (Tables 1 and 2) or any 
potentially interfering compound is found in a blank at greater than 10 
g/L (assuming a response factor of 1 relative to the internal 
standard for compounds not listed in Tables 1 and 2), analysis of 
samples is halted until the source of contamination is eliminated and a 
blank shows no evidence of contamination at this level.
    8.6  The specifications contained in this method can be met if the 
apparatus used is calibrated properly, then maintained in a calibrated 
state. The standards used for calibration (Section 7), calibration 
verification (Section 12.5), and for initial (Section 8.2) and on-going 
(Section 12.7) precision and recovery should be identical, so that the 
most precise results will be obtained. The GC/MS instrument in 
particular will provide the most reproducible results if dedicated to 
the settings and conditions required for the analysis of semi-volatiles 
by this method.
    8.7  Depending on specific program requirements, field replicates 
may be collected to determine the precision of the sampling technique, 
and spiked samples may be required to determine the accuracy of the 
analysis when internal or external standard methods are used.

            9.  Sample Collection, Preservation, and Handling

    9.1  Collect samples in glass containers following conventional 
sampling practices (Reference 7). Composite samples are collected in 
refrigerated glass containers (Section 5.1.3) in accordance with the 
requirements of the sampling program.
    9.2  Maintain samples at 0-4  deg.C from the time collectimn until 
extraction. If residual chlorine is present, add 80 mg sodium 
thiosulfate per liter of water. EPA Methods 330.4 and 330.5 may be used 
to measure residual chlorine (Reference 8).
    9.3  Begin sample extraction within seven days of collection, and 
analyze all extracts within 40 days of extraction.

         10.  Sample Extraction and Concentration (See Figure 4)

    10.1  Labeled compound spiking--measure 1.00  0.01 liter 
of sample into a glass container. For untreated effluents, and samples 
which are expected to be difficult to extract and/or concentrate, 
measure an additional 10.0  0.1 mL and dilute to a final 
volume of 1.00  0.01 liter with reagent water in a glass 
container.
    10.1.1  For each sample or sample lot (to a maximum of 20) to be 
extracted at the same time, place three 1.00  0.10 liter 
aliquots of reagent water in glass containers.
    10.1.2  Spike 0.5 mL of the labeled compound spiking solution 
(Section 6.8) into all samples and one reagant water aliquot.
    10.1.3  Spike 1.0 mL of the precision and recovery standard (Section 
6.14) into the two remaining reagent water aliquots.
    10.1.4  Stir and equilibrate all solutions for 1-2 hr.
    10.2  Base/neutral extraction--place 100-150 mL methylene chloride 
in each continuous extractor and 200-300 in each distilling flask.
    10.2.1  Pour the sample(s), blank, and standard aliquots into the 
extractors. Rinse the glass containers with 50-100 mL methylene chloride 
and add to the respective extractor.
    10.2.2  Adjust the pH of the waters in the extractors to 12-13 with 
6N NaOH while monitoring with a pH meter. Begin the extraction by 
heating the flask until the methylene chloride is boiling. When properly 
adjusted, 1-2 drops of methylene chloride per second will fall from the 
condensor tip into the water. After 1-2 hours of extraction, test the pH 
and readjust to 12-13 if required. Extract for 18-24 hours.
    10.2.3  Remove the distilling flask, estimate and record the volume 
of extract (to the nearest 100 mL), and pour the contents through a 
drying column containing 7 to 10 cm anhydrous sodium sulfate. Rinse the 
distilling flask with 30-50 mL of methylene chloride and pour through 
the drying column. Collect the solution in a 500 mL K-D

[[Page 251]]

evaporator flask equipped with a 10 mL concentrator tube. Seal, label as 
the base/neutral fraction, and concentrate per Sections 10.4 to 10.5.
    10.3  Acid extraction--adjust the pH of the waters in the extractors 
to 2 or less using 6N sulfuric acid. Charge clean distilling flasks with 
300-400 mL of methylene chloride. Test and adjust the pH of the waters 
after the first 1-2 hr of extraction. Extract for 18-24 hours.
    10.3.1  Repeat Section 10.2.3, except label as the acid fraction.
    10.4  Concentration--concentrate the extracts in separate 500 mL K-D 
flasks equipped with 10 mL concentrator tubes.
    10.4.1  Add 1 to 2 clean boiling chips to the flask and attach a 
three-ball macro Snyder column. Prewet the column by adding 
approximately one mL of methylene chloride through the top. Place the K-
D apparatus in a hot water bath so that the entire lower rounded surface 
of the flask is bathed with steam. Adjust the vertical position of the 
apparatus and the water temperature as required to complete the 
concentration in 15 to 20 minutes. At the proper rate of distillation, 
the balls of the column will actively chatter but the chambers will not 
flood. When the liquid has reached an apparent volume of 1 mL, remove 
the K-D apparatus from the bath and allow the solvent to drain and cool 
for at least 10 minutes. Remove the Snyder column and rinse the flask 
and its lower joint into the concentrator tube with 1-2 mL of methylene 
chloride. A 5-mL syringe is recommended for this operation.
    10.4.2  For performance standards (Sections 8.2 and 12.7) and for 
blanks (Section 8.5), combine the acid and base/neutral extracts for 
each at this point. Do not combine the acid and base/neutral extracts 
for samples.
    10.5  Add a clean boiling chip and attach a two ball micro Snyder 
column to the concentrator tube. Prewet the column by adding approx 0.5 
mL methylene chloride through the top. Place the apparatus in the hot 
water bath. Adjust the vertical position and the water temperature as 
required to complete the concentration in 5-10 minutes. At the proper 
rate of distillation, the balls of the column will actively chatter but 
the chambers will not flood. When the liquid reaches an apparent volume 
of approx 0.5 mL, remove the apparatus from the water bath and allow to 
drain and cool for at least 10 minutes. Remove the micro Snyder column 
and rinse its lower joint into the concentrator tube with approx 0.2 mL 
of methylene chloride. Adjust the final volume to 1.0 mL.
    10.6  Transfer the concentrated extract to a clean screw-cap vial. 
Seal the vial with a Teflon-lined lid, and mark the level on the vial. 
Label with the sample number and fraction, and store in the dark at -20 
to -10  deg.C  until ready for analysis.

                           11.  GC/MS Analysis

    11.1  Establish the operating conditions given in Table 3 or 4 for 
analysis of the base/neutral or acid extracts, respectively. For 
analysis of combined extracts (Section 10.4.2), use the operating 
conditions in Table 3.
    11.2  Bring the concentrated extract (Section 10.6) or standard 
(Sections 6.13 through 6.14) to room temperature and verify that any 
precipitate has redissolved. Verify the level on the extract (Sections 
6.6 and 10.6) and bring to the mark with solvent if required.
    11.3  Add the internal standard solution (Section 6.10) to the 
extract (use 1.0 uL of solution per 0.1 mL of extract) immediately prior 
to injection to minimize the possibility of loss by evaporation, 
adsorption, or reaction. Mix thoroughly.
    11.4  Inject a volume of the standard solution or extract such that 
100 ng of the internal standard will be injected, using on-column or 
splitless injection. For 1 mL extracts, this volume will be 1.0 uL. 
Start the GC column initial isothermal hold upon injection. Start MS 
data collection after the solvent peak elutes. Stop data collection 
after the benzo (ghi) perylene or pentachlorophenol peak elutes for the 
base/neutral or acid fraction, respectively. Return the column to the 
initial temperature for analysis of the next sample.

                 12.  System and Laboratory Performance

    12.1  At the beginning of each 8 hr shift during which analyses are 
performed, GC/MS system performance and calibration are verified for all 
pollutants and labeled compounds. For these tests, analysis of the 100 
g/mL calibration standard (Section 6.13) shall be used to 
verify all performance criteria. Adjustment and/or recalibration (per 
Section 7) shall be performed until all performance criteria are met. 
Only after all performance criteria are met may samples, blanks, and 
precision and recovery standards be analyzed.
    12.2  DFTPP spectrum validity--inject 1 L of the DFTPP 
solution (Section 6.11) either separately or within a few seconds of 
injection of the standard (Section 12.1) analyzed at the beginning of 
each shift. The criteria in Table 5 shall be met.
    12.3  Retention times--the absolute retention time of 2,2'-
difluorobiphenyl shall be within the range of 1078 to 1248 seconds and 
the relative retention times of all pollutants and labeled compounds 
shall fall within the limits given in Tables 3 and 4.
    12.4  GC resolution--the valley height between anthracene and 
phenanthrene at m/z 178 (or the analogs at m/z 188) shall not exceed 10 
percent of the taller of the two peaks.
    12.5  Calibration verification--compute the concentration of each 
pollutant (Tables 1

[[Page 252]]

and 2) by isotope dilution (Section 7.4) for those compounds which have 
labeled analogs. Compute the concentration of each pollutant which has 
no labeled analog by the internal standard method (Section 7.5). Compute 
the concentration of the labeled compounds by the internal standard 
method. These concentrations are computed based on the calibration data 
determined in Section 7.
    12.5.1  For each pollutant and labeled compound being tested, 
compare the concentration with the calibration verification limit in 
Table 8. If all compounds meet the acceptance criteria, calibration has 
been verified and analysis of blanks, samples, and precision and 
recovery standards may proceed. If, however, any compound fails, the 
measurement system is not performing properly for that compound. In this 
event, prepare a fresh calibration standard or correct the problem 
causing the failure and repeat the test (Section 12.1), or recalibrate 
(Section 7).
    12.6  Multiple peaks--each compound injected shall give a single, 
distinct GC peak.
    12.7  On-going precision and accuracy.
    12.7.1  Analyze the extract of one of the pair of precision and 
recovery standards (Section 10.1.3) prior to analysis of samples from 
the same lot.
    12.7.2  Compute the concentration of each pollutant (Tables 1 and 2) 
by isotope dilution (Section 7.4) for those compounds which have labeled 
analogs. Compute the concentration of each pollutant which has no 
labeled analog by the internal standard method (Section 7.5). Compute 
the concentration of the labeled compounds by the internal standard 
method.
    12.7.3  For each pollutant and labeled compound, compare the 
concentration with the limits for on-going accuracy in Table 8. If all 
compounds meet the acceptance criteria, system performance is acceptable 
and analysis of blanks and samples may proceed. If, however, any 
individual concentration falls outside of the range given, system 
performance is unacceptable for that compound.

    Note: The large number of compounds in Table 8 present a substantial 
probability that one or more will fail when all compounds are analyzed. 
To determine if the extraction/concentration system is out of control or 
if the failure is caused by probability, proceed as follows:

    12.7.3.1  Analyze the second aliquot of the pair of precision and 
recovery standard (Section 10.1.3).
    12.7.3.2  Compute the concentration of only those pollutants or 
labeled compounds that failed the previous test (Section 12.7.3). If 
these compounds now pass, the extraction/concentration processes are in 
control and analysis of blanks and samples may proceed. If, however, any 
of the same compounds fail again, the extraction/concentration processes 
are not being performed properly for these compounds. In this event, 
correct the problem, re-extract the sample lot (Section 10) and repeat 
the on-going precision and recovery test (Section 12.7).
    12.7.4  Add results which pass the specifications in Section 12.7.2 
to initial and previous on-going data. Update QC charts to perform a 
graphic representation of continued laboratory performance (Figure 5). 
Develop a statement of laboratory accuracy for each pollutant and 
labeled compound by calculating the average percent recovery (R) and the 
standard deviation of percent recovery (sr). Express the accuracy 
as a recovery interval from R-2sr to R+2sr. For example, if 
R=95% and sr=5%, the accuracy is 85-105%.

                     13.  Qualitative Determination

    13.1  Qualititative determination is accomplished by comparison of 
data from analysis of a sample or blank with data from analysis of the 
shift standard (Section 12.1) and with data stored in the spectral 
libraries (Section 7.2.4). Identification is confirmed when spectra and 
retention times agree per the criteria below.
    13.2  Labeled compounds and pollutants having no labeled analog:
    13.2.1  The signals for all characteristic masses stored in the 
spectral library (Section 7.2.4) shall be present and shall maximize 
within the same two consecutive scans.
    13.2.2  Either (1) the background corrected EICP areas, or (2) the 
corrected relative intensities of the mass spectral peaks at the GC peak 
maximum shall agree within a factor of two (0.5 to 2 times) for all 
masses stored in the library.
    13.2.3  The retention time relative to the nearest eluted internal 
standard shall be within 15 scans or 15 seconds, 
whichever is greater of this difference in the shift standard (Section 
12.1).
    13.3  Pollutants having a labled analog:
    13.3.1  The signals for all characteristic masses stored in the 
spectral library (Section 7.2.4) shall be present and shall maximize 
within the same two consecutive scans.
    13.3.2.  Either (1) the background corrected EICP areas, or (2) the 
corrected relative intensities of the mass spectral peaks at the GC peak 
maximum shall agree within a factor of two for all masses stored in the 
spectral library.
    13.3.3.  The retention time difference between the pollutant and its 
labeled analog shall agree within  6 scans or  6 
seconds (whichever is greater) of this difference in the shift standard 
(Section 12.1).
    13.4  Masses present in the experimental mass spectrum that are not 
present in the reference mass spectrum shall be accounted for by 
contaminant or background ions. If

[[Page 253]]

the experimental mass spectrum is contaminated, an experienced 
spectrometrist (Section 1.4) is to determine the presence or absence of 
the cmmpound.

                     14.  Quantitative Determination

    14.1  Isotope dilution--by adding a known amount of a labeled 
compound to every sample prior to extraction, correction for recovery of 
the pollutant can be made because the pollutant and its labeled analog 
exhibit the same effects upon extraction, concentration, and gas 
chromatography. Relative response (RR) values for mixtures are used in 
conjunction with calibration curves described in Section 7.4 to 
determine concentrations directly, so long as labeled compound spiking 
levels are constant. For the phenml example given in Figure 1 (Section 
7.4.1), RR would be equal to 1.114. For this RR value, the phenol 
calibration curve given in Figure 1 indicates a concentration of 27 
g/mL in the sample extract (Cex).
    14.2  Internal standard--compute the concentration in the extract 
using the response factor determined from calibration data (Section 7.5) 
and the following equation: Cex(g/mL)=(As x Cis/
(Ais x RF) where Cex is the concentration of the compound in 
the extract, and the other terms are as defined in Section 7.5.1.
    14.3  The concentration of the pollutant in water is computed using 
the volumes of the original water sample (Section 10.1) and the final 
extract volume (Section 10.5), as follows: Concentration in water 
(g/L)=(Cex x Vex)/Vs where Vex is the 
extract volume in mL, and Vs is the sample volume in liters.
    14.4  If the EICP area at the quantitiation mass for any compound 
exceeds the calibration range of the system, the extract of the dilute 
aliquot (Section 10.1) is analyzed by isotope dilution; otherwise, the 
extract is diluted by a factor of 10, 9 L of internal standard 
solution (Section 6.10) are added to a 1.0 mL aliquot, and this diluted 
extract is analyzed by the internal standard method (Section 14.2). 
Quantify each compound at the highest concentration level within the 
calibration range.
    14.5  Report results for all pollutants and labeled compounds 
(Tables 1 and 2) found in all standards, blanks, and samples in 
g/L, to three significant figures. Results for samples which 
have been diluted are reported at the least dilute level at which the 
area at the quantitation mass is within the calibration range (Section 
14.4) and the labeled compound recovery is within the normal range for 
the method (Section 15.4).

                    15.  Analysis of Complex Samples

    15.1  Untreated effluents and other samples frequently contain high 
levels (>1000 g/L) of the compounds of interest, interfering 
compounds, and/or polymeric materials. Some samples will not concentrate 
to one mL (Section 10.5); others will overload the GC column and/or mass 
spectrometer.
    15.2  Analyze the dilute aliquot (Section 10.1) when the sample will 
not concentrate to 1.0 mL. If a dilute aliquot was not extracted, and 
the sample holding time (Section 9.3) has not been exceeded, dilute an 
aliquot of the sample with reagent water and re-extract (Section 10.1); 
otherwise, dilute the extract (Section 14.4) and analyze by the internal 
standard method (Section 14.2).
    15.3  Recovery of internal standard-- the EICP area of the internal 
standard should be within a factor of two of the area in the shift 
standard (Section 12.1). If the absolute areas of the labeled compounds 
are within a factor of two of the respective areas in the shift 
standard, and the internal standard area is less than one-half of its 
respective area, then internal standard loss in the extract has 
occurred. In this case, use one of the labeled compounds (perferably a 
polynuclear aromatic hydrocarbon) to compute the concentration of a 
pollutant with no labeled analog.
    15.4  Recovery of labeled compounds-- in most samples, labeled 
compound recoveries will be similar to those from reagent water (Section 
12.7). If the labeled compound recovery is outside the limits given in 
Table 8, the dilute extract (Section 10.1) is analyzed as in Section 
14.4. If the recoveries of all labeled compounds and the internal 
staldard are low (per the criteria above), then a loss in instrument 
sensitivity is the most likely cause. In this case, the 100 g/
mL calibration standard (Section 12.1) shall be analyzed and calibration 
verified (Section 12.5). If a loss in sensitivity has occurred, the 
instrument shall be repaired, the performance specifications in Section 
12 shall be met, and the extract reanalyzed. If a loss in instrument 
sensitivity has not occurred, the method does not work on the sample 
being analyzed and the result may not be reported for regulatory 
compliance purposes.

                         16.  Method Performance

    16.1  Interlaboratory performance for this method is detailed in 
references 9 and 10.
    16.2  A chromatogram of the 100 g/mL acid/base/neutral 
calibration standard (Section 6.13) is shown in Figure 6.

                               References

    1. ``Performance Tests for the Evaluation of Computerized Gas 
Chromatography/Mass Spectrometry Equipment and Laboratories'' USEPA, 
EMSL/Cincinnati, OH 45268, EPA-600/4-80-025 (April 1980).
    2. ``Working with Carcinogens,'' DHEW, PHS, CDC, NIOSH, Publication 
77-206, (August 1977).

[[Page 254]]

    3. ``OSHA Safety and Health Standards, General Industry'' OSHA 2206, 
29 CFR part 1910 (January 1976).
    4. ``Safety in Academic Chemistry Laboratories, '' ACS Committee on 
Chemical Safety (1979).
    5. ``Reference Compound to Calibrate Ion Abundance Measurement in 
Gas Chromatography-Mass Spectrometry Systems,'' J.W. Eichelberger, L.E. 
Harris, and W.L. Budde, Anal. Chem., 47, 955 (1975).
    6. ``Handbook of Analytical Quality Control in Water and Wastewater 
Laboratories,'' USEPA, EMSL/Cincinnati, OH 45268, EPA-600/4-79-019 
(March 1979).
    7. ``Standard Practice for Sampling Water,'' ASTM Annual Book of 
Standards, ASTM, Philadelphia, PA, 76 (1980).
    8. ``Methods 330.4 and 330.5 for Total Residual Chlorine,'' USEPA, 
EMSL/ Cincinnati, OH 45268, EPA 600/4-70-020 (March 1979).
    9. Colby, B.N., Beimer, R.G., Rushneck, D.R., and Telliard, W.A., 
``Isotope Dilution Gas Chromatography-Mass Spectrometry for the 
determination of Priority Pollutants in Industrial Effluents.'' USEPA, 
Effluent Guidelines Division, Washington, DC 20460 (1980).
    10. ``Inter-laboratory Validation of US Environmental Protection 
Agency Method 1625,'' USEPA, Effluent Guidelines Division, Washington, 
DC 20460 (June 15, 1984).

               Table 1--Base/Neutral Extractable Compounds              
------------------------------------------------------------------------
                                             CAS                        
           Compound             STORET     registry    EPA-EGD    NPDES 
------------------------------------------------------------------------
Acenaphthene.................     34205      83-32-9     001 B     001 B
Acenaphthylene...............     34200     208-96-8     077 B     002 B
Anthracene...................     34220     120-12-7     078 B     003 B
Benzidine....................     39120      92-87-5     005 B     004 B
Benzo(a)anthracene...........     34526      56-55-3     072 B     005 B
Benzo(b)fluoranthene.........     34230     205-99-2     074 B     007 B
Benzo(k)fluoranthene.........     34242     207-08-9     075 B     009 B
Benzo(a)pyrene...............     34247      50-32-8     073 B     006 B
Benzo(ghi)perylene...........     34521     191-24-2     079 B     008 B
Biphenyl (Appendix C)........     81513      92-52-4     512 B  ........
Bis(2-chloroethyl) ether.....     34273     111-44-4     018 B     011 B
Bis(2-chloroethyoxy)methane..     34278     111-91-1     043 B     010 B
Bis(2-chloroisopropyl) ether.     34283     108-60-1     042 B     012 B
Bis(2-ethylhexyl) phthalate..     39100     117-81-7     066 B     013 B
4-bromophenyl phenyl ether...     34636     101-55-3     041 B     014 B
Butyl benzyl phthalate.......     34292      85-68-7     067 B     015 B
n-C10 (Appendix C)...........     77427     124-18-5     517 B  ........
n-C12 (Appendix C)...........     77588     112-40-2     506 B  ........
n-C14 (Appendix C)...........     77691     629-59-4     518 B  ........
n-C16 (Appendix C)...........     77757     544-76-3     519 B  ........
n-C18 (Appendix C)...........     77804     593-45-3     520 B  ........
n-C20 (Appendix C)...........     77830     112-95-8     521 B  ........
n-C22 (Appendix C)...........     77859     629-97-0     522 B  ........
n-C24 (Appendix C)...........     77886     646-31-1     523 B  ........
n-C26 (Appendix C)...........     77901     630-01-3     524 B  ........
n-C28 (Appendix C)...........     78116     630-02-4     525 B  ........
n-C30 (Appendix C)...........     78117     638-68-6     526 B  ........
Carbazole (4c)...............     77571      86-74-8     528 B  ........
2-chloronaphthalene..........     34581      91-58-7     020 B     016 B
4-chlorophenyl phenyl ether..     34641    7005-72-3     040 B     017 B
Chrysene.....................     34320     218-01-9     076 B     018 B
P-cymene (Appendix C)........     77356      99-87-6     513 B  ........
Dibenzo(a,h)anthracene.......     34556      53-70-3     082 B     019 B
Dibenzofuran (Appendix C and                                            
 4c).........................     81302     132-64-9     505 B  ........
Dibenzothiophene (Synfuel)...     77639     132-65-0     504 B  ........
Di-n-butyl phthalate.........     39110      84-74-2     068 B     026 B
1,2-dichlorobenzene..........     34536      95-50-1     025 B     020 B
1,3-dichlorobenzene..........     34566     541-73-1     026 B     021 B
1,4-dichlorobenzene..........     34571     106-46-7     027 B     022 B
3,3-dichlorobenzidine........     34631      91-94-1     028 B     023 B
Diethyl phthalate............     34336      84-66-2     070 B     024 B
2,4-dimethylphenol...........     34606     105-67-9     034 A     003 A
Dimethyl phthalate...........     34341     131-11-3     071 B     025 B
2,4-dinitrotoluene...........     34611     121-14-2     035 B     027 B
2,6-dinitrotoluene...........     34626     606-20-2     036 B     028 B
Di-n-octyl phthalate.........     34596     117-84-0     069 B     029 B
Diphenylamine (Appendix C)...     77579     122-39-4     507 B  ........
Diphenyl ether (Appendix C)..     77587     101-84-8     508 B  ........
1,2-diphenylhydrazine........     34346     122-66-7     037 B     030 B
Fluoranthene.................     34376     206-44-0     039 B     031 B
Fluorene.....................     34381      86-73-7     080 B     032 B

[[Page 255]]

                                                                        
Hexachlorobenzene............     39700     118-74-1     009 B     033 B
Hexachlorobutadiene..........     34391      87-68-3     052 B     034 B
Hexachloroethane.............     34396      67-72-1     012 B     036 B
Hexachlorocyclopentadiene....     34386      77-47-4     053 B     035 B
Indeno(1,2,3-cd)pyrene.......     34403     193-39-5     083 B     037 B
Isophorone...................     34408      78-59-1     054 B     038 B
Naphthalene..................     34696      91-20-3     055 B     039 B
B-naphthylamine (Appendix C).     82553      91-59-8     502 B  ........
Nitrobenzene.................     34447      98-95-3     056 B     040 B
N-nitrosodimethylamine.......     34438      62-75-9     061 B     041 B
N-nitrosodi-n-propylamine....     34428     621-64-7     063 B     042 B
N-nitrosodiphenylamine.......     34433      86-30-3     062 B     043 B
Phenanthrene.................     34461      85-01-8     081 B     044 B
Phenol.......................     34694     108-95-2     065 A     010 A
a-Picoline (Synfuel).........     77088    109-06-89     503 B  ........
Pyrene.......................     34469     129-00-0     084 B     045 B
styrene (Appendix C).........     77128     100-42-5     510 B  ........
a-terpineol (Appendix C).....     77493      98-55-5     509 B  ........
1,2,3-trichlorobenzene (4c)..     77613      87-61-6     529 B  ........
1,2,4-trichlorobenzene.......     34551     120-82-1     008 B     046 B
------------------------------------------------------------------------


                   Table 2--Acid Extractable Compounds                  
------------------------------------------------------------------------
                                             CAS                        
           Compound             STORET     registry    EPA-EGD    NPDES 
------------------------------------------------------------------------
4-chloro-3-methylphenol......     34452      59-50-7     022 A     008 A
2-chlorophenol...............     34586      95-57-8     024 A     001 A
2,4-dichlorophenol...........     34601     120-83-2     031 A     002 A
2,4-dinitrophenol............     34616      51-28-5     059 A     005 A
2-methyl-4,6-dinitrophenol...     34657     534-52-1     060 A     004 A
2-nitrophenol................     34591      88-75-5     057 A     006 A
4-nitrophenol................     34646     100-02-7     058 A     007 A
Pentachlorophenol............     39032      87-86-5     064 A     009 A
2,3,6-trichlorophenol (4c)...     77688     93-37-55     530 A  ........
2,4,5-trichlorophenol (4c)...  ........      95-95-4     531 A  ........
2,4,6-trichlorophenol........     34621      88-06-2     021 A     011 A
------------------------------------------------------------------------


                        Table 3--Gas Chromatography of Base/Neutral Extractable Compounds                       
----------------------------------------------------------------------------------------------------------------
                                                                          Retention time              Detection 
  EGD                                                          ------------------------------------   limit \2\ 
No.\1\                         Compound                           Mean                              (g/
                                                                  (sec)    EGD Ref     Relative          L)     
----------------------------------------------------------------------------------------------------------------
164...  2,2-difluorobiphenyl (int std)........................      1163       164     1.000-1.000          10  
061...  N-nitrosodimethylamine................................       385       164        ns                50  
603...  alpha picoline-d7.....................................       417       164     0.326-0.393          50  
703...  alpha picoline........................................       426       603     1.006-1.028          50  
610...  styrene-d5............................................       546       164     0.450-0.488          10  
710...  styrene...............................................       549       610     1.002-1.009          10  
613...  p-cymene-d14..........................................       742       164     0.624-0.652          10  
713...  p-cymene..............................................       755       613     1.008-1.023          10  
265...  phenol-d5.............................................       696       164     0.584-0.613          10  
365...  phenol................................................       700       265     0.995-1.010          10  
218...  bis(2-chloroethyl) ether-d8...........................       696       164     0.584-0.607          10  
318...  bis(2-chloroethyl) ether..............................       704       218     1.007-1.016          10  
617...  n-decane-d22..........................................       698       164     0.585-0.615          10  
717...  n-decane..............................................       720       617     1.022-1.038          10  
226...  1,3-dichlorobenzene-d4................................       722       164     0.605-0.636          10  
326...  1,3-dichlorobenzene...................................       724       226     0.998-1.008          10  
227...  1,4-dichlorobenzene-d4................................       737       164     0.601-0.666          10  
327...  1,4-dichlorobenzene...................................       740       227     0.997-1.009          10  
225...  1,2-dichlorobenzene-d4................................       758       164     0.632-0.667          10  
325...  1,2-dichlorobenzene...................................       760       225     0.995-1.008          10  
242...  bis(2-chloroisopropyl) ether-d12......................       788       164     0.664-0.691          10  
342...  bis(2-chloroisopropyl) ether..........................       799       242     1.010-1.016          10  
212...  hexachloroethane-13C..................................       819       164     0.690-0.717          10  
312...  hexachloroethane......................................       823       212     0.999-1.001          10  
063...  N-nitrosodi-n-propylamine.............................       830       164        ns                20  

[[Page 256]]

                                                                                                                
256...  nitrobenzene-d5.......................................       845       164     0.706-0.727          10  
356...  nitrobenzene..........................................       849       256     1.002-1.007          10  
254...  isophorone-d8.........................................       881       164     0.747-0.767          10  
354...  isophorone............................................       889       254     0.999-1.017          10  
234...  2,4-dimethyl phenol-d3................................       921       164     0.781-0.803          10  
334...  2,4-dimethylphenol....................................       924       234     0.999-1.003          10  
043...  bis(2-chloroethoxy) methane...........................       939       164        ns                10  
208...  1,2,4-trichlorobenzene-d3.............................       955       164     0.813-0.830          10  
308...  1,2,4-trichlorobenzene................................       958       208     1.000-1.005          10  
255...  naphthalene-d8........................................       963       164     0.819-0.836          10  
355...  naphthalene...........................................       967       255     1.001-1.006          10  
609...  alpha-terpineol-d3....................................       973       164     0.829-0.844          10  
709...  alpha-terpineol.......................................       975       609     0.998-1.008          10  
606...  n-dodecane-d26........................................       953       164     0.730-0.908          10  
706...  n-dodecane............................................       981       606     0.986-1.051          10  
529...  1,2,3-trichlorobenzene................................      1003       164        ns                10  
252...  hexachlorobutadiene-13C4..............................      1005       164     0.856-0.871          10  
352...  hexachlorobutadiene...................................      1006       252     0.999-1.002          10  
253...  hexachlorocyclopentadiene-13C4........................      1147       164     0.976-0.986          10  
353...  hexachlorocyclopentadiene.............................      1142       253     0.999-1.001          10  
220...  2-chloronaphthalene-d7................................      1185       164     1.014-1.024          10  
320...  2-chloronaphthalene...................................      1200       220     0.997-1.007          10  
518...  n-tetradecane.........................................      1203       164        ns                10  
612...  Biphenyl-d10..........................................      1205       164     1.016-1.027          10  
712...  Biphenyl..............................................      1195       612     1.001-1.006          10  
608...  Diphenyl ether-d10....................................      1211       164     1.036-1.047          10  
708...  Diphenyl ether........................................      1216       608     0.997-1.009          10  
277...  Acenaphthylene-d8.....................................      1265       164     1.080-1.095          10  
377...  Acenaphthylene........................................      1247       277     1.000-1.004          10  
271...  Dimethyl phthalate-d4.................................      1269       164     1.083-1.102          10  
371...  Dimethyl phthalate....................................      1273       271     0.998-1.005          10  
236...  2,6-dinitrotoluene-d3.................................      1283       164     1.090-1.112          10  
336...  2,6-dinitrotoluene....................................      1300       236     1.001-1.005          10  
201...  Acenaphthene-d10......................................      1298       164     1.107-1.125          10  
301...  Acenaphthene..........................................      1304       201     0.999-1.009          10  
605...  Dibenzofuran-d8.......................................      1331       164     1.134-1.155          10  
705...  Dibenzofuran..........................................      1335       605     0.998-1.007          10  
602...  Beta-naphthylamine-d7.................................      1368       164     1.163-1.189          50  
702...  Beta-naphthylamine....................................      1371       602     0.996-1.007          50  
280...  Fluorene-d10..........................................      1395       164     1.185-1.214          10  
380...  Fluorene..............................................      1401       281     0.999-1.008          10  
240...  4-chlorophenyl phenyl ether-d5........................      1406       164     1.194-1.223          10  
340...  4-chlorophenyl phenyl ether...........................      1409       240     0.990-1.015          10  
270...  Diethyl phthalate-d4..................................      1409       164     1.197-1.229          10  
370...  Diethyl phthalate.....................................      1414       270     0.996-1.006          10  
619...  n-hexadecane-d34......................................      1447       164     1.010-1.478          10  
719...  n-hexadecane..........................................      1469       619     1.013-1.020          10  
235...  2,4-dinitrotoluene-d3.................................      1359       164     1.152-1.181          10  
335...  2,4-dinitrotoluene....................................      1344       235     1.000-1.002          10  
237...  1,2-diphenylhydrazine-d8..............................      1433       164     1.216-1.248          20  
337...  1,2-diphenylhydrazine (\3\)...........................      1439       237     0.999-1.009          20  
607...  Diphenylamine-d10.....................................      1437       164     1.213-1.249          20  
707...  Diphenylamine.........................................      1439       607     1.000-1.007          20  
262...  N-nitrosodiphenylamine-d6.............................      1447       164     1.225-1.252          20  
362...  N-nitrosodiphenylamine (\4\)..........................      1464       262     1.000-1.002          20  
041...  4-bromophenyl phenyl ether............................      1498       164     1.271-1.307          10  
209...  Hexachlorobenzene-13C6................................      1521       164     1.288-1.327          10  
309...  Hexachlorobenzene.....................................      1522       209     0.999-1.001          10  
281...  Phenanthrene-d10......................................      1578       164     1.334-1.380          10  
520...  n-octadecane..........................................      1580       164        ns                10  
381...  Phenanthrene..........................................      1583       281     1.000-1.005          10  
278...  Anthracene-d10........................................      1588       164     1.342-1.388          10  
378...  Anthracene............................................      1592       278     0.998-1.006          10  
604...  Dibenzothiophene-d8...................................      1559       164     1.314-1.361          10  
704...  Dibenzothiophene......................................      1564       604     1.000-1.006          10  
528...  Carbazole.............................................      1650       164        ns                20  
621...  n-eicosane-d42........................................      1655       164     1.184-1.662          10  
721...  n-eicosane............................................      1677       621     1.010-1.021          10  
268...  Di-n-butyl phthalate-d4...............................      1719       164     1.446-1.510          10  
368...  Di-n-butyl phthalate..................................      1723       268     1.000-1.003          10  

[[Page 257]]

                                                                                                                
239...  Fluoranthene-d10......................................      1813       164     1.522-1.596          10  
339...  Fluoranthene..........................................      1817       239     1.000-1.004          10  
284...  Pyrene-d10............................................      1844       164     1.523-1.644          10  
384...  Pyrene................................................      1852       284     1.001-1.003          10  
205...  Benzidine-d8..........................................      1854       164     1.549-1.632          50  
305...  Benzidine.............................................      1853       205     1.000-1.002          50  
522...  n-docosane............................................      1889       164        ns                10  
623...  n-tetracosane-d50.....................................      1997       164     1.671-1.764          10  
723...  n-tetracosane.........................................      2025       612     1.012-1.015          10  
067...  Butylbenzyl phthalate.................................      2060       164        ns                10  
276...  Chrysene-d12..........................................      2081       164     1.743-1.837          10  
376...  Chrysene..............................................      2083       276     1.000-1.004          10  
272...  Benzo(a)anthracene-d12................................      2082       164     1.735-1.846          10  
372...  Benzo(a)anthracene....................................      2090       272     0.999-1.007          10  
228...  3,3-dichlorobenzidine-d6..............................      2088       164     1.744-1.848          50  
328...  3,3-dichlorobenzidine.................................      2086       228     1.000-1.001          50  
266...  Bis(2-ethylhexyl) phthalate-d4........................      2123       164     1.771-1.880          10  
366...  Bis(2-ethylhexyl) phthalate...........................      2124       266     1.000-1.002          10  
524...  n-hexacosane..........................................      2147       164        ns                10  
269...  di-n-octyl phthalate-d4...............................      2239       164     1.867-1.982          10  
369...  di-n-octyl phthalate..................................      2240       269     1.000-1.002          10  
525...  n-octacosane..........................................      2272       164        ns                10  
274...  Benzo(b)fluoranthene-d12..............................      2281       164     1.902-2.025          10  
354...  Benzo(b)fluoranthene..................................      2293       274     1.000-1.005          10  
275...  Benzo(k)fluoranthene-d12..............................      2287       164     1.906-2.033          10  
375...  Benzo(k)fluoranthene..................................      2293       275     1.000-1.005          10  
273...  Benzo(a)pyrene-d12....................................      2351       164     1.954-2.088          10  
373...  Benzo(a)pyrene........................................      2350       273     1.000-1.004          10  
626...  N-triacontane-d62.....................................      2384       164     1.972-2.127          10  
726...  N-triacontane.........................................      2429       626     1.011-1.028          10  
083...  Indeno(1,2,3-cd)pyrene................................      2650       164        ns                20  
082...  Dibenzo(a,h)anthracene................................      2660       164        ns                20  
279...  Benzo(ghi)perylene-d12................................      2741       164     2.187-2.524          20  
379...  Benzo(ghi)perylene....................................      2750       279     1.001-1.006          20  
----------------------------------------------------------------------------------------------------------------
\1\ Reference numbers beginning with 0, 1 or 5 indicate a pollutant quantified by the internal standard method; 
  reference numbers beginning with 2 or 6 indicate a labeled compound quantified by the internal standard       
  method; reference numbers beginning with 3 or 7 indicate a pollutant quantified by isotope dilution.          
\2\ This is a minimum level at which the entire GC/MS system must give recognizable mass spectra (background    
  corrected) and acceptable calibration points.                                                                 
\3\ Detected as azobenzene.                                                                                     
\4\ Detected as diphenylamine.                                                                                  
                                                                                                                
ns = specification not available at time of release of method.                                                  
Column: 30 2 m  x  0.25 0.02 mm i.d. 94% methyl, 4% phenyl, 1% vinyl bonded phase fused 
  silica capillary.                                                                                             
Temperature program: 5 min at 30 C; 30 - 280 C at 8 C per min; isothermal at 280 C until benzo(ghi)perylene     
  elutes.                                                                                                       
Gas velocity: 30 5 cm/sec.                                                                          


                            Table 4--Gas Chromatography of Acid Extractable Compounds                           
----------------------------------------------------------------------------------------------------------------
                                                                          Retention time              Detection 
  EGD                                                          ------------------------------------    limit 2  
 No. 1                         Compound                           Mean                              (g/
                                                                  (sec)    EGD Ref     Relative          L)     
----------------------------------------------------------------------------------------------------------------
164...  2,2'-difluorobiphenyl (int std).......................      1163       164     1.000-1.000          10  
224...  2-chlorophenol-d4.....................................       701       164     0.587-0.618          10  
324...  2-chlorophenol........................................       705       224     0.997-1.010          10  
257...  2-nitrophenol-d4......................................       898       164     0.761-0.783          20  
357...  2-nitrophenol.........................................       900       257     0.994-1.009          20  
231...  2,4-dichlorophenol-d3.................................       944       164     0.802-0.822          10  
331...  2,4-dichlorophenol....................................       947       231     0.997-1.006          10  
222...  4-chloro-3-methylphenol-d2............................      1086       164     0.930-0.943          10  
322...  4-chloro-3-methylphenol...............................      1091       222     0.998-1.003          10  
221...  2,4,6-trichlorophenol-d2..............................      1162       164     0.994-1.005          10  
321...  2,4,6-trichlorophenol.................................      1165       221     0.998-1.004          10  
531...  2,4,5-trichlorophenol.................................      1170       164        ns                10  
530...  2,3,6-trichlorophenol.................................      1195       164        ns                10  
259...  2,4-dinitrophenol-d3..................................      1323       164     1.127-1.149          50  
359...  2,4-dinitrophenol.....................................      1325       259     1.000-1.005          50  
258...  4-nitrophenol-d4......................................      1349       164     1.147-1.175          50  
358...  4-nitrophenol.........................................      1354       258     0.997-1.006          50  

[[Page 258]]

                                                                                                                
260...  2-methyl-4,6-dinitrophenol-d2.........................      1433       164     1.216-1.249          20  
360...  2-methyl-4,6-dinitrophenol............................      1435       260     1.000-1.002          20  
264...  Pentachlorophenol-13C6................................      1559       164     1.320-1.363          50  
364...  Pentachlorophenol.....................................      1561       264     0.998-1.002          50  
----------------------------------------------------------------------------------------------------------------
1 Reference numbers beginning with 0, 1 or 5 indicate a pollutant quantified by the internal standard method;   
  reference numbers beginning with 2 or 6 indicate a labeled compound quantified by the internal standard       
  method; reference numbers beginning with 3 or 7 indicate a pollutant quantified by isotope dilution.          
2 This is a minimum level at which the entire GC/MS system must give recognizable mass spectra (background      
  corrected) and acceptable calibration points.                                                                 
                                                                                                                
ns=specification not available at time of release of method.                                                    
Column: 302m x 0.250.02mm i.d. 94% methyl, 4% phenyl, 1% vinyl bonded phase fused silica
  capillary.                                                                                                    
Temperature program: 5 min at 30 C; 8 deg.C/min. to 250C or until pentachlorophenol elutes.                     
Gas velocity: 305 cm/sec.                                                                           


              Table 5--DFTPP Mass Intensity Specifications              
------------------------------------------------------------------------
 Mass                          Intensity required                       
------------------------------------------------------------------------
51....  30-60 percent of mass 198.                                      
68....  Less than 2 percent of mass 69.                                 
70....  Less than 2 percent of mass 69.                                 
127...  40-60 percent of mass 198.                                      
197...  Less than 1 percent of mass 198.                                
199...  5-9 percent of mass 198.                                        
275...  10-30 percent of mass 198.                                      
365...  greater than 1 percent of mass 198                              
441...  present and less than mass 443                                  
442...  40-100 percent of mass 198.                                     
443...  17-23 percent of mass 442.                                      
------------------------------------------------------------------------


    Table 6--Base/Neutral Extractable Compound Characteristic Masses    
------------------------------------------------------------------------
                                                    Labeled   Primary m/
                     Compound                        analog        z    
------------------------------------------------------------------------
Acenaphthene.....................................        d10    154/164 
Acenaphthylene...................................         d8    152/160 
Anthracene.......................................        d10    178/188 
Benzidine........................................         d8    184/192 
Benzo(a)anthracene...............................        d12    228/240 
Benzo(b)fluoranthene.............................        d12    252/264 
Benzo(k)fluoranthene.............................        d12    252/264 
Benzo(a)pyrene...................................        d12    252/264 
Benzo(ghi)perylene...............................        d12    276/288 
Biphenyl.........................................        d10    154/164 
Bis(2-chloroethyl) ether.........................         d8     93/101 
Bis(2-chloroethoxy)methane.......................  .........     93     
Bis(2-chloroisopropyl) ether.....................        d12    121/131 
Bis(2-ethylhexyl) phthalate......................         d4    149/153 
4-bromophenyl phenyl ether.......................  .........    248     
Butyl benzyl phthalate...........................  .........    149     
n-C10............................................        d22     55/66  
n-C12............................................        d26     55/66  
n-C14............................................  .........     55     
n-C16............................................        d34     55/66  
n-C18............................................  .........     55     
n-C20............................................        d42     55/66  
n-C22............................................  .........     55     
n-C24............................................        d50     55/66  
n-C26............................................  .........     55     
n-C28............................................  .........     55     
n-C30............................................        d62     55/66  
Carbazole........................................         d8    167/175 
2-chloronaphthalene..............................         d7    162/169 
4-chlorophenyl phenyl ether......................         d5    204/209 
Chrysene.........................................        d12    228/240 
p-cymene.........................................        d14    114/130 
Dibenzo(a,h)anthracene...........................  .........    278     
Dibenzofuran.....................................         d8    168/176 
Dibenzothiophene.................................         d8    184/192 
Di-n-butyl phthalate.............................         d4    149/153 
1,2-dichlorobenzene..............................         d4    146/152 
1,3-dichlorobenzene..............................         d4    146/152 
1,4-dichlorobenzene..............................         d4    146/152 
3,3-dichlorobenzidine............................         d6    252/258 
Diethyl phthalate................................         d4    149/153 
2,4-dimethylphenol...............................         d3    122/125 
Dimethyl phthalate...............................         d4    163/167 
2,4-dinitrotoluene...............................         d3    164/168 
2,6-dinitrotoluene...............................         d3    165/167 
Di-n-octyl phthalate.............................         d4    149/153 
Diphenylamine....................................        d10    169/179 
Diphenyl ether...................................        d10    170/180 
1,2-diphenylhydrazine\1\.........................        d10     77/82  
Fluoranthene.....................................        d10    202/212 
Fluorene.........................................        d10    166/176 
Hexachlorobenzene................................       13C6    284/292 
Hexachlorobutadiene..............................       13C4    225/231 
Hexachloroethane.................................        13C    201/204 
Hexachlorocyclopentadiene........................       13C4    237/241 
Ideno(1,2,3-cd)pyrene............................  .........    276     
Isophorone.......................................         d8     82/88  
Naphthalene......................................         d8    128/136 
B-naphthylamine..................................         d7    143/150 
Nitrobenzene.....................................         d5    123/128 
N-nitrosodimethylamine...........................  .........     74     
N-nitrosodi-n-propylamine........................  .........     70     
N-nitrosodiphenylamile\2\........................         d6    169/175 
Phenanthrene.....................................        d10    178/188 
Phenol...........................................         d5     94/71  
a-picoline.......................................         d7     93/100 
Pyrene...........................................        d10    202/212 
Styrene..........................................         d5    104/109 
a-terpineol......................................         d3     59/62  
1,2,3-trichlorobenzene...........................         d3    180/183 
1,2,4-trichlorobenzene...........................         d3    180/183 
------------------------------------------------------------------------
\1\ Detected as azobenzene.                                             
\2\ Detected as diphenylamine.                                          


[[Page 259]]


        Table 77--Acid Extractable Compound Characteristic Masses       
------------------------------------------------------------------------
                                                    Labeled   Primary m/
                     Compound                        analog        z    
------------------------------------------------------------------------
4-chloro-3-methylphenol..........................         d2    107/109 
2-chlorophenol...................................         d4    128/132 
2,4-dichlorophenol...............................         d3    162/167 
2,4-dinitrophenol................................         d3    184/187 
2-methyl-4,6-dinitrophenol.......................         d2    198/200 
2-nitrophenol....................................         d4    139/143 
4-nitrophenol....................................         d4    139/143 
Pentachlorophenol................................       13C6    266/272 
2,3,6-trichlorophenol............................         d2    196/200 
2,4,5-trichlorophenol............................         d2    196/200 
2,4,6-trichlorophenol............................         d2    196/200 
------------------------------------------------------------------------


                               Table 8--Acceptance Criteria for Performance Tests                               
----------------------------------------------------------------------------------------------------------------
                                                                      Acceptance criteria                       
                                              ------------------------------------------------------------------
                                               Initial precision and      Labeled      Calibration    On-going  
  EGD                  Compound                   accuracy section       compound     verification    accuracy  
 No.1                                           8.2.3 (g/L)   recovery sec.    sec. 12.5    sec. 11.6 R
                                              ----------------------- 8.3 and 14.2 P  (g/  (g/
                                                   s          X          (percent)         mL)           L)     
----------------------------------------------------------------------------------------------------------------
301...  Acenaphthene.........................        21       79-134  ..............        80-125        72-144
201...  Acenaphthene-d10.....................        38       38-147          20-270        71-141        30-180
377...  Acenaphtylene........................        38       69-186  ..............        60-166        61-207
277...  Acenaphthylene-d8....................        31       38-146          23-239        66-152        33-168
378...  Anthracene...........................        41       58-174  ..............        60-168        50-199
278...  Anthracene-d10.......................        49       31-194          14-419        58-171        23-242
305...  Benzidine............................       119       16-518  ..............        34-296        11-672
205...  Benzidine-d8.........................       269        ns-ns           ns-ns         ns-ns         ns-ns
372...  Benzo(a)anthracene...................        20       65-168  ..............        70-142        62-176
272...  Benzo(a)anthracene-d12...............        41       25-298          12-605        28-357        22-329
374...  Benzo(b)fluoranthene.................       183       32-545  ..............        61-164         20-ns
274...  Benzo(b)fluoranthene-d12.............       168       11-577           ns-ns         14-ns         ns-ns
375...  Benzo(k)fluoranthene.................        26       59-143  ..............         13-ns        53-155
275...  Benzo(k)fluoranthene-d12.............       114       15-514           ns-ns         13-ns        ns-685
373...  Benzo(a)pyrene.......................        26       62-195  ..............        78-129        59-206
273...  Benzo(a)pyrene-d12...................        24       35-181          21-290         12-ns        32-194
379...  Benzo(ghi)perylene...................        21       72-160  ..............        69-145        58-168
279...  Benzo(ghi)perylene-d12...............        45       29-268          14-529         13-ns        25-303
712...  Biphenyl (Appendix C)................        41       75-148  ..............        58-171        62-176
612...  Biphenyl-d12.........................        43       28-165           ns-ns        52-192        17-267
318...  Bis(2-chloroethyl) ether.............        34       55-196  ..............        61-164        50-213
218...  Bis(2-chloroethyl) ether-d8..........        33       29-196          15-372        52-194        25-222
043...  Bis(2-chloroethoxy)methane*..........        27       43-153  ..............        44-228        39-166
342...  Bis(2-chloroisopropyl) ether.........        17       81-138  ..............        67-148        77-145
242...  Bis(2-chloroisopropyl)ether-d12......        27       35-149          20-260        44-229        30-169
366...  Bis(2-ethylhexyl) phthalate..........        31       69-220  ..............        76-131        64-232
266...  Bis(2-ethylhexyl) phthalate-d4.......        29       32-205          18-364        43-232        28-224
041...  4-bromophenyl phenyl ether*..........        44       44-140  ..............        52-193        35-172
067...  Butyl benzyl phthalate*..............        31       19-233  ..............        22-450        35-170
717...  n-C10 (Appendix C)...................        51       24-195  ..............        42-235        19-237
617...  n-C10-d22............................        70       ns-298           ns-ns        44-227        ns-504
706...  n-C12 (Appendix C)...................        74       35-369  ..............        60-166        29-424
606...  n-C12-d26............................        53       ns-331           ns-ns        41-242        ns-408
518...  n-C14 (Appendix C)*..................       109       ns-985  ..............        37-268         ns-ns
719...  n-C16 (Appendix C)...................        33       80-162  ..............        72-138        71-181
619...  n-C16-d34............................        46       37-162          18-308        54-186        28-202
520...  n-C18 (Appendix C)*..................        39       42-131  ..............        40-249        35-167
721...  n-C20 (Appendix C)...................        59       53-263  ..............        54-184        46-301
621...  n-C20-d42............................        34       34-172          19-306        62-162        29-198
522...  n-C22 (Appendix C)*..................        31       45-152  ..............        40-249        39-195
723...  n-C24 (Appendix C)...................        11       80-139  ..............        65-154        78-142
623...  n-C24-d50............................        28       27-211          15-376        50-199        25-229
524...  n-C26 (Appendix C)*..................        35       35-193  ..............        26-392        31-212
525...  n-C28 (Appendix C)*..................        35       35-193  ..............        26-392        31-212
726...  n-C30 (Appendix C)...................        32       61-200  ..............        66-152        56-215
626...  n-C30-d62............................        41       27-242          13-479        24-423        23-274
528...  Carbazole (4c)*......................        38       36-165  ..............        44-227        31-188
320...  2-chloronaphthalene..................       100       46-357  ..............        58-171        35-442
220...  2-chloronaphthalene-d7...............        41       30-168          15-324        72-139        24-204
322...  4-chloro-3-methylphenol..............        37       76-131  ..............        85-115        62-159
222...  4-chloro-3-methylphenol-d2...........       111       30-174          ns-613        68-147        14-314
324...  2-chlorophenol.......................        13       79-135  ..............        78-129        76-138
224...  2-chlorophenol-d4....................        24       36-162          23-255        55-180        33-176
340...  4-chlorophenyl phenyl ether..........        42       75-166  ..............        71-142        63-194

[[Page 260]]

                                                                                                                
240...  4-chlorophenyl phenyl ether-d5.......        52       40-161          19-325        57-175        29-212
376...  Chrysene.............................        51       59-186  ..............        70-142        48-221
276...  Chrysene-d12.........................        69       33-219          13-512        24-411        23-290
713...  p-cymene (Appendix C)................        18       76-140  ..............        79-127        72-147
613...  p-cymene-d14.........................        67       ns-359           ns-ns        66-152        ns-468
082...  Dibenzo(a,h)anthracene*..............        55       23-299  ..............        13-761        19-340
705...  Dibenzofuran (Appendix C)............        20       85-136  ..............        73-136        79-146
605...  Dibenzofuran-d8......................        31       47-136          28-220        66-150        39-160
704...  Dibenzothiophene (Synfuel)...........        31       79-150  ..............        72-140        70-168
604...  Dibenzothiophene-d8..................        31       48-130          29-215        69-145        40-156
368...  Di-n-butyl phthalate.................        15       76-165  ..............        71-142        74-169
268...  Di-n-butyl phthalate-d4..............        23       23-195          13-346        52-192        22-209
325...  1,2-dichlorobenzene..................        17       73-146  ..............        74-135        70-152
225...  1,2-dichlorobenzene-d4...............        35       14-212          ns-494        61-164        11-247
326...  1,3-dichlorobenzene..................        43       63-201  ..............        65-154        55-225
226...  1,3-dichlorobenzene-d4...............        48       13-203          ns-550        52-192        ns-260
327...  1,4-dichlorobenzene..................        42       61-194  ..............        62-161        53-219
227...  1,4-dichlorobenzene-d4...............        48       15-193          ns-474        65-153        11-245
328...  3,3-dichlorobenzidine................        26       68-174  ..............        77-130        64-185
228...  3,3-dichlorobenzidine-d6.............        80       ns-562           ns-ns        18-558         ns-ns
331...  2,4-dichlorophenol...................        12       85-131  ..............        67-149        83-135
231...  2,4-dichlorophenol-d3................        28       38-164          24-260        64-157        34-182
370...  Diethyl phthalate....................        44       75-196  ..............        74-135        65-222
270...  Diethyl phthalate-d4.................        78       ns-260           ns-ns        47-211         ns-ns
334...  2,4-dimethylphenol...................        13       62-153  ..............        67-150        60-156
234...  2,4-dimethylphenol-d3................        22       15-228          ns-449        58-172        14-242
371...  Dimethyl phthalate...................        36       74-188  ..............        73-137        67-207
271...  Dimethyl phthalate-d4................       108       ns-640           ns-ns        50-201         ns-ns
359...  2,4-dinitrophenol....................        18       72-134  ..............        75-133        68-141
259...  2,4-dinitrophenol-d3.................        66       22-308           ns-ns        39-256        17-378
335...  2,4-dinitrotoluene...................        18       75-158  ..............        79-127        72-164
235...  2,4-dinitrotoluene-d3................        37       22-245          10-514        53-187        19-275
336...  2,6-dinitrotoluene...................        30       80-141  ..............        55-183        70-159
236...  2,6-dinitrotoluene-d3................        59       44-184          17-442        36-278        31-250
369...  Di-n-octyl phthalate.................        16       77-161  ..............        71-140        74-166
269...  Di-n-octyl phthalate-d4..............        46       12-383           ns-ns        21-467        10-433
707...  Diphenylamine (Appendix C)...........        45       58-205  ..............        57-176        51-231
607...  Diphenylamine-d10....................        42       27-206          11-488        59-169        21-249
708...  Diphenyl ether (Appendix C)..........        19       82-136  ..............        83-120        77-144
608...  Diphenyl ether-d10...................        37       36-155          19-281        77-129        29-186
337...  1,2-diphenylhydrazine................        73       49-308  ..............        75-134        40-360
237...  1,2-diphenylhydrazine-d10............        35       31-173          17-316        58-174        26-200
339...  Fluoranthene.........................        33       71-177  ..............        67-149        64-194
239...  Fluoranthene-d10.....................        35       36-161          20-278        47-215        30-187
380...  Fluorene.............................        29       81-132  ..............        74-135        70-151
280...  Fluorene-d10.........................        43       51-131          27-238        61-164        38-172
309...  Hexachlorobenzene....................        16       90-124  ..............        78-128        85-132
209...  Hexachlorobenzene-13C6...............        81       36-228          13-595        38-265        23-321
352...  hexachlorobutadiene..................        56       51-251  ..............        74-135        43-287
252...  hexachlorobutadiene-13C4.............        63       ns-316           ns-ns        68-148        ns-413
312...  hexachloroethane.....................       227        21-ns  ..............        71-141         13-ns
212...  hexachloroethane-13C1................        77       ns-400           ns-ns        47-212        ns-563
353...  hexachlorocyclopentadiene............        15       69-144  ..............        77-129        67-148
253...  hexachlorocyclopentadiene-13C4.......        60        ns-ns           ns-ns        47-211         ns-ns
083...  ideno(1,2,3-cd)pyrene*...............        55       23-299  ..............        13-761        19-340
354...  isophorone...........................        25       76-156  ..............        70-142        70-168
254...  isophorone-d8........................        23       49-133          33-193        52-194        44-147
360...  2-methyl-4,6-dinitrophenol...........        19       77-133  ..............        69-145        72-142
260...  2-methyl-4,6-dinitrophenol-d2........        64       36-247          16-527        56-177        28-307
355...  naphthalene..........................        20       80-139  ..............        73-137        75-149
255...  naphthalene-d8.......................        39       28-157          14-305        71-141        22-192
702...  B-naphthylamine (Appendix C).........        49        10-ns  ..............        39-256         ns-ns
602...  B-naphthylamine-d7...................        33        ns-ns           ns-ns        44-230         ns-ns
356...  nitrobenzene.........................        25       69-161  ..............        85-115        65-169
256...  nitrobenzene-d5......................        28       18-265           ns-ns        46-219        15-314
357...  2-nitrophenol........................        15       78-140  ..............        77-129        75-145
257...  2-nitrophenol-d4.....................        23       41-145          27-217        61-163        37-158

[[Page 261]]

                                                                                                                
358...  4-nitrophenol........................        42       62-146  ..............        55-183        51-175
258...  4-nitrophenol-d4.....................       188       14-398           ns-ns        35-287         ns-ns
061...  N-nitrosodimethylamile*..............       198       21-472  ..............        40-249        12-807
063...  N-nitrosodi-n-proplyamine*...........       198       21-472  ..............        40-249        12-807
362...  N-nitrosodiphenylamine...............        45       65-142  ..............        68-148        53-173
262...  N-nitrosodiphenylamine-d6............        37       54-126          26-256        59-170        40-166
364...  pentachlorophenol....................        21       76-140  ..............        77-130        71-150
264...  pentachlorophenol-13C6...............        49       37-212          18-412        42-237        29-254
381...  phenanthrene.........................        13       93-119  ..............        75-133        87-126
281...  phenanthrene-d10.....................        40       45-130          24-241        67-149        34-168
365...  phenol...............................        36       77-127  ..............        65-155        62-154
265...  phenol-d5............................       161       21-210           ns-ns        48-208         ns-ns
703...  a-picoline (Synfuel).................        38       59-149  ..............        60-165        50-174
603...  a-picoline-d7........................       138       11-380           ns-ns        31-324        ns-608
384...  pyrene...............................        19       76-152  ..............        76-132        72-159
284...  pyrene-d10...........................        29       32-176          18-303        48-210        28-196
710...  styrene (Appendix C).................        42       53-221  ..............        65-153        48-244
610...  styrene-d5...........................        49       ns-281           ns-ns        44-228        ns-348
709...  a-terpineol (Appendix C).............        44       42-234  ..............        54-186        38-258
609...  a-terpineol-d3.......................        48       22-292          ns-672        20-502        18-339
529...  1,2,3-trichlorobenzene (4c)*.........        69       15-229  ..............        60-167        11-297
308...  1,2,4-trichlorobenzene...............        19       82-136  ..............        78-128        77-144
208...  1,2,4-trichlorobenzene-d3............        57       15-212          ns-592        61-163        10-282
530...  2,3,6-trichlorophenol (4c)*..........        30       58-137  ..............        56-180        51-153
531...  2,4,5-trichlorophenol (4c)*..........        30       58-137  ..............        56-180        51-153
321...  2,4,6-trichlorophenol................        57       59-205  ..............        81-123        48-244
221...  2,4,6-trichlorophenol-d2.............        47       43-183          21-363        69-144        34-226
----------------------------------------------------------------------------------------------------------------
\1\ Reference numbers beginning with 0, 1 or 5 indicate a pollutant quantified by the internal standard method; 
  reference numbers beginning with 2 or 6 indicate a labeled compound quantified by the internal standard       
  method; reference numbers beginning with 3 or 7 indicate a pollutant quantified by isotope dilution.          
                                                                                                                
* Measured by internal standard; specification derived from related compound.                                   
ns=no specification; limit is outside the range that can be measured reliably.                                  


[[Page 262]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.057


[[Page 263]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.058


[[Page 264]]

[GRAPHIC] [TIFF OMITTED] TC02JY92.059

[49 FR 43261, Oct. 26, 1984; 50 FR 692, 695, Jan. 4, 1985, as amended at 
51 FR 23702, June 30, 1986]

[[Page 265]]

 Appendix B to Part 136--Definition and Procedure for the Determination 
              of the Method Detection Limit--Revision 1.11

                               Definition

    The method detection limit (MDL) is defined as the minimum 
concentration of a substance that can be measured and reported with 99% 
confidence that the analyte concentration is greater than zero and is 
determined from analysis of a sample in a given matrix containing the 
analyte.

                          Scope and Application

    This procedure is designed for applicability to a wide variety of 
sample types ranging from reagent (blank) water containing analyte to 
wastewater containing analyte. The MDL for an analytical procedure may 
vary as a function of sample type. The procedure requires a complete, 
specific, and well defined analytical method. It is essential that all 
sample processing steps of the analytical method be included in the 
determination of the method detection limit.
    The MDL obtained by this procedure is used to judge the significance 
of a single measurement of a future sample.
    The MDL procedure was designed for applicability to a broad variety 
of physical and chemical methods. To accomplish this, the procedure was 
made device- or instrument-independent.

                                Procedure

    1. Make an estimate of the detection limit using one of the 
following:
    (a) The concentration value that corresponds to an instrument 
signal/noise in the range of 2.5 to 5.
    (b) The concentration equivalent of three times the standard 
deviation of replicate instrumental measurements of the analyte in 
reagent water.
    (c) That region of the standard curve where there is a significant 
change in sensitivity, i.e., a break in the slope of the standard curve.
    (d) Instrumental limitations.
    It is recognized that the experience of the analyst is important to 
this process. However, the analyst must include the above considerations 
in the initial estimate of the detection limit.
    2. Prepare reagent (blank) water that is as free of analyte as 
possible. Reagent or interference free water is defined as a water 
sample in which analyte and interferent concentrations are not detected 
at the method detection limit of each analyte of interest. Interferences 
are defined as systematic errors in the measured analytical signal of an 
established procedure caused by the presence of interfering species 
(interferent). The interferent concentration is presupposed to be 
normally distributed in representative samples of a given matrix.
    3. (a) If the MDL is to be determined in reagent (blank) water, 
prepare a laboratory standard (analyte in reagent water) at a 
concentration which is at least equal to or in the same concentration 
range as the estimated method detection limit. (Recommend between 1 and 
5 times the estimated method detection limit.) Proceed to Step 4.
    (b) If the MDL is to be determined in another sample matrix, analyze 
the sample. If the measured level of the analyte is in the recommended 
range of one to five times the estimated detection limit, proceed to 
Step 4.
    If the measured level of analyte is less than the estimated 
detection limit, add a known amount of analyte to bring the level of 
analyte between one and five times the estimated detection limit.
    If the measured level of analyte is greater than five times the 
estimated detection limit, there are two options.
    (1) Obtain another sample with a lower level of analyte in the same 
matrix if possible.
    (2) The sample may be used as is for determining the method 
detection limit if the analyte level does not exceed 10 times the MDL of 
the analyte in reagent water. The variance of the analytical method 
changes as the analyte concentration increases from the MDL, hence the 
MDL determined under these circumstances may not truly reflect method 
variance at lower analyte concentrations.
    4. (a) Take a minimum of seven aliquots of the sample to be used to 
calculate the method detection limit and process each through the entire 
analytical method. Make all computations according to the defined method 
with final results in the method reporting units. If a blank measurement 
is required to calculate the measured level of analyte, obtain a 
separate blank measurement for each sample aliquot analyzed. The average 
blank measurement is subtracted from the respective sample measurements.
    (b) It may be economically and technically desirable to evaluate the 
estimated method detection limit before proceeding with 4a. This will: 
(1) Prevent repeating this entire procedure when the costs of analyses 
are high and (2) insure that the procedure is being conducted at the 
correct concentration. It is quite possible that an inflated MDL will be 
calculated from data obtained at many times the real MDL even though the 
level of analyte is less than five times the calculated method detection 
limit. To insure that the estimate of the method detection limit is a 
good estimate, it is necessary to determine that a lower concentration 
of analyte will not result in a significantly lower method detection 
limit. Take two aliquots of the sample to be used to calculate the 
method detection limit and process each

[[Page 266]]

through the entire method, including blank measurements as described 
above in 4a. Evaluate these data:
    (1) If these measurements indicate the sample is in desirable range 
for determination of the MDL, take five additional aliquots and proceed. 
Use all seven measurements for calculation of the MDL.
    (2) If these measurements indicate the sample is not in correct 
range, reestimate the MDL, obtain new sample as in 3 and repeat either 
4a or 4b.
    5. Calculate the variance (S2) and standard deviation (S) of 
the replicate measurements, as follows:
[GRAPHIC] [TIFF OMITTED] TR31AU93.074

where:

X; i=1 to n, are the analytical results in the final method 
          reporting units obtained from the n sample aliquots and 
           refers to the sum of the X values from i=l to n.

    6. (a) Compute the MDL as follows:

             MDL = t(n-1,1- = 0.99)  (S)

where:
    MDL = the method detection limit
    t(n-1,1- = .99) = the students' t value 
appropriate for a 99% confidence level and a standard deviation estimate 
with n-1 degrees of freedom. See Table.
    S = standard deviation of the replicate analyses.

    (b) The 95% confidence interval estimates for the MDL derived in 6a 
are computed according to the following equations derived from 
percentiles of the chi square over degrees of freedom distribution 
(2/df).
    LCL = 0.64 MDL
    UCL = 2.20 MDL
    where: LCL and UCL are the lower and upper 95% confidence limits 
respectively based on seven aliquots.
    7. Optional iterative procedure to verify the reasonableness of the 
estimate of the MDL and subsequent MDL determinations.
    (a) If this is the initial attempt to compute MDL based on the 
estimate of MDL formulated in Step 1, take the MDL as calculated in Step 
6, spike the matrix at this calculated MDL and proceed through the 
procedure starting with Step 4.
    (b) If this is the second or later iteration of the MDL calculation, 
use S2 from the current MDL calculation and S2 from the 
previous MDL calculation to compute the F-ratio. The F-ratio is 
calculated by substituting the larger S2 into the numerator 
S2A and the other into the denominator S2B. The 
computed F-ratio is then compared with the F-ratio found in the table 
which is 3.05 as follows: if S2A/S2B<3.05, then 
compute the pooled standard deviation by the following equation:

[GRAPHIC] [TIFF OMITTED] TR31AU93.075


    if S2A/S2B>3.05, respike at the most recent 
calculated MDL and process the samples through the procedure starting 
with Step 4. If the most recent calculated MDL does not permit 
qualitative identification when samples are spiked at that level, report 
the MDL as a concentration between the current and previous MDL which 
permits qualitative identification.
    (c) Use the Spooled as calculated in 7b to compute the final 
MDL according to the following equation:

                        MDL=2.681 (Spooled)

where 2.681 is equal to t(12, 1- =.99).
    (d) The 95% confidence limits for MDL derived in 7c are computed 
according to the following equations derived from precentiles of the chi 
squared over degrees of freedom distribution.
    LCL=0.72 MDL
    UCL=1.65 MDL
where LCL and UCL are the lower and upper 95% confidence limits 
respectively based on 14 aliquots.

     Tables of Students' t Values at the 99 Percent Confidence Level    
------------------------------------------------------------------------
                                                   Degrees              
                                                      of                
              Number of replicates                 freedom   tcn-1, .99)
                                                    (n-1)               
------------------------------------------------------------------------
7...............................................          6        3.143
8...............................................          7        2.998
9...............................................          8        2.896
10..............................................          9        2.821
11..............................................         10        2.764
16..............................................         15        2.602
21..............................................         20        2.528
26..............................................         25        2.485
31..............................................         30        2.457
61..............................................         60        2.390
00..............................................         00        2.326
------------------------------------------------------------------------

                                Reporting

    The analytical method used must be specifically identified by number 
or title ald the MDL for each analyte expressed in the appropriate 
method reporting units. If the analytical method permits options which 
affect the method detection limit, these conditions must be specified 
with the MDL value. The sample matrix used to determine the MDL must 
also be identified with MDL value. Report the mean analyte level with 
the MDL

[[Page 267]]

and indicate if the MDL procedure was iterated. If a laboratory standard 
or a sample that contained a known amount analyte was used for this 
determination, also report the mean recovery.
    If the level of analyte in the sample was below the determined MDL 
or exceeds 10 times the MDL of the analyte in reagent water, do not 
report a value for the MDL.

[49 FR 43430, Oct. 26, 1984; 50 FR 694, 696, Jan. 4, 1985, as amended at 
51 FR 23703, June 30, 1986]

  Appendix C to Part 136--Inductively Coupled Plasma--Atomic Emission 
  Spectrometric Method for Trace Element Analysis of Water and Wastes 
                              Method 200.7

                        1. Scope and Application

    1.1  This method may be used for the determination of dissolved, 
suspended, or total elements in drinking water, surface water, and 
domestic and industrial wastewaters.
    1.2  Dissolved elements are determined in filtered and acidified 
samples. Appropriate steps must be taken in all analyses to ensure that 
potential interferences are taken into account. This is especially true 
when dissolved solids exceed 1500 mg/L. (See Section 5.)
    1.3  Total elements are determined after appropriate digestion 
procedures are performed. Since digestion techniques increase the 
dissolved solids content of the samples, appropriate steps must be taken 
to correct for potential interference effects. (See Section 5.)
    1.4  Table 1 lists elements for which this method applies along with 
recommended wavelengths and typical estimated instrumental detection 
limits using conventional pneumatic nebulization. Actual working 
detection limits are sample dependent and as the sample matrix varies, 
these concentrations may also vary. In time, other elements may be added 
as more information becomes available and as required.
    1.5  Because of the differences between various makes and models of 
satisfactory instruments, no detailed instrumental operating 
instructions can be provided. Instead, the analyst is referred to the 
instruction provided by the manufacturer of the particular instrument.

                          2. Summary of Method

    2.1  The method describes a technique for the simultaneous or 
sequential multielement determination of trace elements in solution. The 
basis of the method is the measurement of atomic emission by an optical 
spectroscopic technique. Samples are nebulized and the aerosol that is 
produced is transported to the plasma torch where excitation occurs. 
Characteristic atomic-line emission spectra are produced by a radio-
frequency inductively coupled plasma (ICP). The spectra are dispersed by 
a grating spectrometer and the intensities of the lines are monitored by 
photomultiplier tubes. The photocurrents from the photomultiplier tubes 
are processed and controlled by a computer system. A background 
correction technique is required to compensate for variable background 
contribution to the determination of trace elements. Background must be 
measured adjacent to analyte lines on samples during analysis. The 
position selected for the background intensity measurement, on either or 
both sides of the analytical line, will be determined by the complexity 
of the spectrum adjacent to the analyte line. The position used must be 
free of spectral interference and reflect the same change in background 
intensity as occurs at the analyte wavelength measured. Background 
correction is not required in cases of line broadening where a 
background correction measurement would actually degrade the analytical 
result. The possibility of additional interferences named in 5.1 (and 
tests for their presence as described in 5.2) should also be recognized 
and appropriate corrections made.

                             3. Definitions

    3.1  Dissolved--Those elements which will pass through a 0.45 
m membrane filter.
    3.2  Suspended--Those elements which are retained by a 0.45 
m membrane filter.
    3.3  Total--The concentration determined on an unfiltered sample 
following vigorous digestion (Section 9.3), or the sum of the dissolved 
plus suspended concentrations. (Section 9.1 plus 9.2).
    3.4  Total recoverable--The concentration determined on an 
unfiltered sample following treatment with hot, dilute mineral acid 
(Section 9.4).
    3.5  Instrumental detection limit--The concentration equivalent to a 
signal, due to the analyte, which is equal to three times the standard 
deviation of a series of ten replicate measurements of a reagent blank 
signal at the same wavelength.
    3.6  Sensitivity--The slope of the analytical curve, i.e. functional 
relationship between emission intensity and concentration.
    3.7  Instrument check standard--A multielement standard of known 
concentrations prepared by the analyst to monitor and verify instrument 
performance on a daily basis. (See 7.6.1)
    3.8  Interference check sample--A solution containing both 
interfering and analyte elemelts of known concentration that can be used 
to verify background and interelement correction factors. (See 7.6.2.)
    3.9  Quality control sample--A solution obtained from an outside 
source having known, concentration values to be used to verify the 
calibration standards. (See 7.6.3)

[[Page 268]]

    3.10  Calibration standards--A series of known standard solutions 
used by the analyst for calibration of the instrument (i.e., preparation 
of the analytical curve). (See 7.4)
    3.11  Linear dynamic range--The concentration range over which the 
analytical curve remains linear.
    3.12  Reagent blank--A volume of deionized, distilled water 
containing the same acid matrix as the calibration standards carried 
through the entire analytical scheme. (See 7.5.2)
    3.13  Calibration blank--A volume of deionized, distilled water 
acidified with HNO3 and HCl. (See 7.5.1)
    3.14  Methmd of standard addition--The standard addition technique 
involves the use of the unknown and the unknown plus a known amount of 
standard. (See 10.6.1.)

                                4. Safety

    4.1  The toxicity of carcinogenicity of each reagent used in this 
method has not been precisely defined; however, each chemical compound 
should be treated as a potential health hazard. From this viewpoint, 
exposure to these chemicals must be reduced to the lowest possible level 
by whatever means available. The laboratory is repsonsible for 
maintaining a current awareness file of OSHA regulations regarding the 
safe handling of the chemicals specified in this method. A reference 
file of material data handling sheets should also be made available to 
all personnel involved in the chemical analysis. Additional references 
to laboratory safety are available and have been identified (14.7, 
14.8 and 14.9) for the information of the analyst.

                            5. Interferences

    5.1  Several types of interference effects may contribute to 
inaccuracies in the determination of trace elements. They can be 
summarized as follows:
    5.1.1  Spectral interferences can be categorized as (1) overlap of a 
spectral line from another element; (2) unresolved overlap of molecular 
band spectra; (3) background contribution from continuous or 
recombination phenomena; and (4) background contribution from stray 
light from the line emission of high concentration elements. The first 
of these effects can be compensated by utilizing a computer correction 
of the raw data, requiring the monitoring and measurement of the 
interfering element. The second effect may require selection of an 
alternate wavelength. The third and fourth effects can usually be 
compensated by a background correction adjacent to the analyte line. In 
addition, users of simultaneous multi-element instrumentation must 
assume the responsibility of verifying the absence of spectral 
interference from an element that could occur in a sample but for which 
there is no channel in the instrument array. Listed in Table 2 are some 
interference effects for the recommended wavelengths given in Table 1. 
The data in Table 2 are intended for use only as a rudimentary guide for 
the indication of potential spectral interferences. For this purpose, 
linear relations between concentration and intensity for the analytes 
and the interferents can be assumed. The Interference information, which 
was collected at the Ames Laboratory,1 is expressed as analyte 
concentration equivalents (i.e. false analyte concentrations) arising 
from 100 mg/L of the interferent element. The suggested use of this 
information is as follows: Assume that arsenic (at 193.696 nm) is to be 
determined in a sample containing approximately 10 mg/L of aluminum. 
According to Table 2, 100 mg/L of aluminum would yield a false signal 
for arsenic equivalent to approximately 1.3 mg/L. Therefore, 10 mg/L of 
aluminum would result in a false signal for arsenic equivalent to 
approximately 0.13 mg/L. The reader is cautioned that other analytical 
systems may exhibit somewhat different levels of interference than those 
shown in Table 2, and that the interference effects must be evaluated 
for each individual system.
---------------------------------------------------------------------------

    \1\ Ames Laboratory, USDOE, Iowa State University, Ames Iowa 50011.
---------------------------------------------------------------------------

    Only those interferents listed were investigated and the blank 
spaces in Table 2 indicate that measurable interferences were not 
observed for the interferent concentrations listed in Table 3. 
Generally, interferences were discernible if they produced peaks or 
background shifts corresponding to 2-5% of the peaks generated by the 
analyte concentrations also listed in Table 3.
    At present, information on the listed silver and potassium 
wavelengths are not available but it has been reported that second order 
energy from the magnesium 383.231 nm wavelength interferes with the 
listed potassium line at 766.491 nm.
    5.1.2  Physical interferences are generally considered to be effects 
associated with the sample nebulization and transport processes. Such 
properties as change in viscosity and surface tension can cause 
significant inaccuracies especially in samples which may contain high 
dissolved solids and/or acid concentrations. The use of a peristaltic 
pump may lessen these interferences. If these types of interferences are 
operative, they must be reduced by dilution of the sample and/or 
utilization of standard addition techniques. Another problem which can 
occur from high dissolved solids is salt buildup at the tip of the 
nebulizer. This affects aersol flow rate causing instrumental drift. 
Wetting the argon prior to nebulization, the use of a tip washer, or 
sample dilution have been used to control this problem. Also, it has 
been reported that better control of the argon flow rate improves 
instrument performance. This

[[Page 269]]

is accomplished with the use of mass flow controllers.
    5.1.3  Chemical Interferences are characterized by molecular 
compound formation, ionization effects and solute vaporization effects. 
Normally these effects are not pronounced with the ICP technique, 
however, if observed they can be minimized by careful selection of 
operating conditions (that is, incident power, observation position, and 
so forth), by buffering of the sample, by matrix matching, and by 
standard addition procedures. These types of interferences can be highly 
dependent on matrix type and the specific analyte element.
    5.2  It is recommended that whenever a new or unusual sample matrix 
is encountered, a series of tests be performed prior to reporting 
concentration data for analyte elements. These tests, as outlined in 
5.2.1 through 5.2.4, will ensure the analyst that neither positive nor 
negative interference effects are operative on any of the analyte 
elements thereby distorting the accuracy of the reported values. 
    5.2.1  Serial dilution. If the analyte concentration is sufficiently 
high (minimally a factor of 10 above the instrumental detection limit 
after dilution), an analysis of a dilution should agree within 5 percent 
of the original determination (or within some acceptable control limit 
(14.3) that has been established for that matrix.). If not, a chemical 
or physical interference effect should be suspected.
    5.2.2  Spike addition. The recovery of a spike addition added at a 
minimum level of 10X the instrumental detection limit (maximum 100X) to 
the original determination should be recovered to within 90 to 110 
percent or within the established control limit for that matrix. If not, 
a matrix effect should be suspected. The use of a standard addition 
analysis procedure can usually compensate for this effect.
    Caution: The standard addition technique does not detect coincident 
spectral overlap. If suspected, use of computerized compensation, an 
alternate wavelength, or comparison with an alternate method is 
recommended (See 5.2.3).
    5.2.3  Comparison with alternate method of analysis. When 
investigating a new sample matrix, comparison tests may be performed 
with other analytical techniques such as atomic absorption spectrometry, 
or other approved methodology.
    5.2.4  Wavelength scanning of analyte line region. If the 
appropriate equipment is available, wavelength scanning can be performed 
to detect potential spectral interferences.

                              6. Apparatus

    6.1  Inductively Coupled Plasma-Atomic Emission Spectrometer.
    6.1.1  Computer controlled atomic emission spectrometer with 
background correction.
    6.1.2  Radiofrequency generator.
    6.1.3  Argon gas supply, welding grade or better.
    6.2  Operating conditions--Because of the differences between 
various makes and models of satisfactory instruments, no detailed 
operating instructions can be provided. Instead, the analyst should 
follow the instructions provided by the manufacturer of the particular 
instrument. Sensitivity, instrumental detection limit, precision, linear 
dynamic range, and interference effects must be investigated and 
established for each individual analyte line on that particular 
instrument. It is the responsibility of the analyst to verify that the 
instrument configuration and operating conditions used satisfy the 
analytical requirements and to maintain quality control data confirming 
instrument performance and analytical results.

                        7. Reagents and Standards

    7.1  Acids used in the preparation of standards and for sample 
processing must be ultra-high purity grade or equivalent. Redistilled 
acids are acceptable.
    7.1.1  Acetic acid, conc. (sp gr 1.06).
    7.1.2  Hydrochloric acid, conc. (sp gr 1.19).
    7.1.3  Hydrochloric acid, (1+1): Add 500 mL conc. HCl (sp gr 1.19) 
to 400 mL deionized, distilled water and dilute to 1 liter.
    7.1.4  Nitric acid, conc. (sp gr 1.41).
    7.1.5  Nitric acid, (1+1): Add 500 mL conc. HNO3 (sp gr 1.41) 
to 400 mL deionized, distilled water and dilute to 1 liter.
    7.2  Deionized, distilled water: Prepare by passing distilled water 
through a mixed bed of cation and anion exchange resins. Use deionized, 
distilled water for the preparation of all reagents, calibration 
standards and as dilution water. The purity of this water must be 
equivalent to ASTM Type II reagent water of Specification D 1193 (14.6).
    7.3  Standard stock solutions may be purchased or prepared from 
ultra high purity grade chemicals or metals. All salts must be dried for 
1 h at 105  deg.C unless otherwise specified.
    (CAUTION: Many metal salts are extremely toxic and may be fatal if 
swallowed. Wash hands thoroughly after handling.)
    Typical stock solution preparation procedures follow:
    7.3.1  Aluminum solution, stock, 1 mL=100g Al: Dissolve 
0.100 g of aluminum metal in an acid mixture of 4 mL of (1+1) HCl and 1 
mL of conc. HNO3 in a beaker. Warm gently to effect solution. When 
solution is complete, transfer quantitatively to a liter flask add an 
additional 10 mL of (1+1) HCl and dilute to 1,000 mL with deionized, 
distilled water.
    7.3.2  Antimony solution stock, 1 mL=100 g Sb: Dissolve 
0.2669 g K(SbO)C4H4O6 in deionized distilled water, add 
10 mL (1+1) HCl

[[Page 270]]

and dilute to 1,000 mL with deionized, distilled water.
    7.3.3  Arsenic solution, stock, 1 mL=100 g As: Dissolve 
0.1320 g of As2O3 in 100 mL of deionized, distilled water 
containing 0.4 g NaOH. Acidify the solution with 2 mL conc. HNO3 
and dilute to 1,000 mL with deionized, distilled water.
    7.3.4  Barium solution, stock, 1 mL=100 g Ba: Dissolve 
0.1516 g BaCl2 (dried at 250  deg.C for 2 hrs) in 10 mL deionized, 
distilled water with 1 mL (1+1) HCl. Add 10.0 mL (1+1) HCl and dilute to 
1,000 with mL deionized, distilled water.
    7.3.5  Beryllium solution, stock, 1 mL=100 g Be: Do not 
dry. Dissolve 1.966 g BeSO4bullet4H2O, in deionized, 
distilled water, add 10.0 mL conc. HNO3 and dilute to 1,000 mL with 
deionized, distilled water.
    7.3.6  Boron solution, stock, 1 mL=100 g B: Do not dry. 
Dissolve 0.5716 g anhydrous H3BO3 in deionized, distilled 
water and dilute to 1,000 mL. Use a reagent meeting ACS specifications, 
keep the bottle tightly stoppered and store in a desiccator to prevent 
the entrance of atmospheric moisture.
    7.3.7  Cadmium solution, stock, 1 mL=100 g Cd: Dissolve 
0.1142 g CdO in a minimum amount of (1+1) HNO3. Heat to increase 
rate of dissolution. Add 10.0 mL conc. HNO3 and dilute to 1,000 mL 
with deionized, distilled water.
    7.3.8  Calcium solution, stock, 1 mL=100 g Ca: Suspend 
0.2498 g CaCO3 dried at 180  deg.C for 1 h before weighing in 
deionized, distilled water and dissolve cautiously with a minimum amount 
of (1+1) HNO3. Add 10.0 mL conc. HNO3 and dilute to 1,000 mL 
with deionized, distilled water.
    7.3.9  Chromium solution, stock, 1 mL=100 g Cr: Dissolve 
0.1923 g of CrO3 in deionized, distilled water. When solution is 
complete, acidify with 10 mL conc. HNO3 and dilute to 1,000 mL with 
deionized, distilled water.
    7.3.10  Cobalt solution, stock, 1 mL=100 g Co: Dissolve 
0.1000 g of cobalt metal in a minimum amount of (1+1) HNO3. Add 
10.0 mL (1+1) HCl and dilute to 1,000 mL with deionized, distilled 
water.
    7.3.11  Copper solution, stock, 1 mL=100 g Cu: Dissolve 
0.1252 g CuO in a minimum amount of (1+1) HNO3. Add 10.0 mL conc. 
HNO3 and dilute to 1,000 mL with deionized, distilled water.
    7.3.12  Iron solution, stock, 1 mL=100 g Fe: Dissolve 
0.1430 g Fe2O3 in a warm mixture of 20 mL (1+1) HCl and 2 mL 
of conc. HNO3. Cool, add an additional 5 mL of conc. HNO3 and 
dilute to 1,000 mL with deionized, distilled water.
    7.3.13  Lead solution, stock, 1 mL=100 g Pb: Dissolve 
0.1599 g Pb(NO3)2 in a minimum amount of (1+1) HNO3. Add 
10.0 mL conc. HNO3 and dilute to 1,000 mL with deionized, distilled 
water.
    7.3.14  Magnesium solution, stock, 1 mL=100 g Mg: Dissolve 
0.1658 g MgO in a minimum amount of (1+1) HNO3. Add 10.0 mL conc. 
HNO3 and dilute to 1,000 mL with deionized, distilled water.
    7.3.15  Manganese solution, stock, 1 mL=100 g Mn: Dissolve 
0.1000 g of manganese metal in the acid mixture 10 mL conc. HCl and 1 mL 
conc. HNO3, and dilute to 1,000 mL with deionized, distilled water.
    7.3.16  Molybdenum solution, stock, 1 mL=100 g Mo: Dissolve 
0.2043 g (NH4)2MoO4 in deionized, distilled water and 
dilute to 1,000 mL.
    7.3.17  Nickel solution, stock, 1 mL=100 g Ni: Dissolve 
0.1000 g of nickel metal in 10 mL hot conc. HNO3, cool and dilute 
to 1,000 mL with deionized, distilled water.
    7.3.18  Potassium solution, stock, 1 mL=100 g K: Dissolve 
0.1907 g KCl, dried at 110  deg.C, in deionized, distilled water and 
dilute to 1,000 mL.
    7.3.19  Selenium solution, stock, 1 mL=100 g Se: Do not 
dry. Dissolve 0.1727 g H2SeO3 (actual assay 94.6%) in 
deionized, distilled water and dilute to 1,000 mL.
    7.3.20  Silica solution, stock, 1 mL=100 g SiO2: Do 
not dry. Dissolve 0.4730 g Na2SiO3 bullet9H2O in 
deionized, distilled water. Add 10.0 mL conc. HNO3 and dilute to 
1,000 mL with deionized, distilled water.
    7.3.21  Silver solution, stock, 1 mL=100 g Ag: Dissolve 
0.1575 g AgNO3 in 100 mL of deionized, distilled water and 10 mL 
conc. HNO3. Dilute to 1,000 mL with deionized, distilled water.
    7.3.22  Sodium solution, stock, 1 mL=100 g Na: Dissolve 
0.2542 g NaCl in deionized, distilled water. Add 10.0 mL conc. HNO3 
and dilute to 1,000 mL with deionized, distilled water.
    7.3.23  Thallium solution, stock, 1 mL=100 g Tl: Dissolve 
0.1303 g TlNO3 in deionized, distilled water. Add 10.0 mL conc. 
HNO3 and dilute to 1,000 mL with deionized, distilled water.
    7.3.24  Vanadium solution, stock, 1 mL=100 g V: Dissolve 
0.2297 NH4VO3 in a minimum amount of conc. HNO3. Heat to 
increase rate of dissolution. Add 10.0 mL conc. HNO3 and dilute to 
1,000 mL with deionized, distilled water.
    7.3.25  Zinc solution, stock, 1 mL=100 g Zn: Dissolve 
0.1245 g ZnO in a minimum amount of dilute HNO3. Add 10.0 mL conc. 
HNO3 and dilute to 1,000 mL deionized, distilled water.
    7.4  Mixed calibration standard solutions--Prepare mixed calibration 
standard solutions by combining appropriate volumes of the stock 
solutions in volumetric flasks. (See 7.4.1 thru 7.4.5) Add 2 mL of (1+1) 
HNO3 and 10 mL of (1+1) HC1 and dilute to 100 mL with deionized, 
distilled water. (See Notes 1 and 6.) Prior to preparing the mixed 
standards, each stock solution should be analyzed separately to 
determine possible spectral interference or the presence of impurities. 
Care should be taken when preparing the

[[Page 271]]

mixed standards that the elemelts are compatible and stable. Transfer 
the mixed standard solutions to a FEP fluorocarbon or unused 
polyethylene bottle for storage. Fresh mixed standards should be 
prepared as needed with the realization that concentration can change on 
aging. Calibration standards must be initially verified using a quality 
control sample and monitored weekly for stability (See 7.6.3). Although 
not specifically required, some typical calibration standard 
combinations follow when using those specific wavelengths listed in 
Table 1.
    7.4.1  Mixed standard solution I--Manganese, beryllium, cadmium, 
lead, and zinc.
    7.4.2  Mixed standard solution II--Barium, copper, iron, vanadium, 
and cobalt.
    7.4.3  Mixed standard solution III--Molybdenum, silica, arsenic, and 
selenium.
    7.4.4  Mixed standard solution IV--Calcium, sodium, potassium, 
aluminum, chromium and nickel.
    7.4.5  Mixed standard solution V--Antimony, boron, magnesium, 
silver, and thallium.

    Note: 1. If the addition of silver to the recommended acid 
combination results in an initial precipitation, add 15 mL of deionized 
distilled water and warm the flask until the solution clears. Cool and 
dilute to 100 mL with deionized, distilled water. For this acid 
combination the silver concentration should be limited to 2 mg/L. Silver 
under these conditions is stable in a tap water matrix for 30 days. 
Higher concentrations of silver require additional HCl.

    7.5  Two types of blanks are required for the analysis. The 
calibration blank (3.13) is used in establishing the analytical curve 
while the reagent blank (3.12) is used to correct for possible 
contamination resulting from varying amounts of the acids used in the 
sample processing.
    7.5.1  The calibration blank is prepared by diluting 2 mL of (1+1) 
HNO3 and 10 mL of (1+1) HCl to 100 mL with deionized, distilled 
water. (See Note 6.) Prepare a sufficient quantity to be used to flush 
the system between standards and samples.
    7.5.2  The reagent blank must contain all the reagents and in the 
same volumes as used in the processing of the samples. The reagent blank 
must be carried through the complete procedure and contain the same acid 
concentration in the final solution as the sample solution used for 
analysis.
    7.6  In addition to the calibration standards, an instrument check 
standard (3.7), an interference check sample (3.8) and a quality control 
sample (3.9) are also required for the analyses.
    7.6.1  The instrument check standard is prepared by the analyst by 
combining compatible elements at a concentration equivalent to the 
midpoint of their respective calibration curves. (See 12.1.1.)
    7.6.2  The interference check sample is prepared by the analyst in 
the following manner. Select a representative sample which contains 
minimal concentrations of the analytes of interest but known 
concentration of interfering elements that will provide an adequate test 
of the correction factors. Spike the sample with the elements of 
interest at the approximate concentration of either 100 g/L or 
5 times the estimated detection limits given in Table 1. (For effluent 
samples of expected high concentrations, spike at an appropriate level.) 
If the type of samples analyzed are varied, a synthetically prepared 
sample may be used if the above criteria and intent are met.
    7.6.3  The quality control sample should be prepared in the same 
acid matrix as the calibration standards at a concentration near 1 mg/L 
and in accordance with the instructions provided by the supplier. The 
Quality Assurance Branch of EMSL-Cincinnati will either supply a quality 
control sample or information where one of equal quality can be 
procured. (See 12.1.3.)

                   8. Sample Handling and Preservation

    8.1  For the determination of trace elements, contamination and loss 
are of prime concern. Dust in the laboratory environment, impurities in 
reagents and impurities on laboratory apparatus which the sample 
contacts are all sources of potential contamination. Sample containers 
can introduce either positive or negative errors in the measurement of 
trace elements by (a) contributing contaminants through leaching or 
surface desorption and (b) by depleting concentrations through 
adsorption. Thus the collection and treatment of the sample prior to 
analysis requires particular attention. Laboratory glassware including 
the sample bottle (whether polyethylene, polyproplyene or FEP-
fluorocarbon) should be thoroughly washed with detergent and tap water; 
rinsed with (1+1) nitric acid, tap water, (1+1) hydrochloric acid, tap 
and finally deionized, distilled water in that order (See Notes 2 and 
3).

    Note: 2. Chromic acid may be useful to remove organic deposits from 
glassware; however, the analyst should be cautioned that the glassware 
must be thoroughly rinsed with water to remove the last traces of 
chromium. This is especially important if chromium is to be included in 
the analytical scheme. A commercial product, NOCHROMIX, available from 
Godax Laboratories, 6 Varick St., New York, NY 10013, may be used in 
place of chromic acid. Chromic acid should not be used with plastic 
bottles.

    Note: 3. If it can be documented through an active analytical 
quality control program using spiked samples and reagent blanks, that 
certain steps in the cleaning procedure

[[Page 272]]

are not required for routine samples, those steps may be eliminated from 
the procedure.

    8.2  Before collection of the sample a decision must be made as to 
the type of data desired, that is dissolved, suspended or total, so that 
the appropriate preservation and pretreatment steps may be accomplished. 
Filtration, acid preservation, etc., are to be performed at the time the 
sample is collected or as soon as possible thereafter.
    8.2.1  For the determination of dissolved elements the sample must 
be filtered through a 0.45-m membrane filter as soon as 
practical after collection. (Glass or plastic filtering apparatus are 
recommended to avoid possible contamination.) Use the first 50-100 mL to 
rinse the filter flask. Discard this portion and collect the required 
volume of filtrate. Acidify the filtrate with (1+1) HNO3 to a pH of 
2 or less. Normally, 3 mL of (1+1) acid per liter should be sufficient 
to preserve the sample.
    8.2.2  For the determination of suspended elements a measured volume 
of unpreserved sample must be filtered through a 0.45-m 
membrane filter as soon as practical after collection. The filter plus 
suspended material should be transferred to a suitable container for 
storage and/or shipment. No preservative is required.
    8.2.3  For the determination of total or total recoverable elements, 
the sample is acidified with (1+1) HNO3 to pH 2 or less as soon as 
possible, preferably at the time of collection. The sample is not 
filtered before processing.

                          9. Sample Preparation

    9.1  For the determinations of dissolved elements, the filtered, 
preserved sample may often be analyzed as received. The acid matrix and 
concentration of the samples and calibration standards must be the same. 
(See Note 6.) If a precipitate formed upon acidification of the sample 
or during transit or storage, it must be redissolved before the analysis 
by adding additional acid and/or by heat as described in 9.3.
    9.2  For the determination of suspended elements, transfer the 
membrane filter containing the insoluble material to a 150-mL Griffin 
beaker and add 4 mL conc. HNO3. Cover the beaker with a watch glass 
and heat gently. The warm acid will soon dissolve the membrane. Increase 
the temperature of the hot plate and digest the material. When the acid 
has nearly evaporated, cool the beaker and watch glass and add another 3 
mL of conc. HNO3. Cover and continue heating until the digestion is 
complete, generally indicated by a light colored digestate. Evaporate to 
near dryness (2 mL), cool, and 10 mL HCl (1+1) and 15 mL deionized, 
distilled water per 100 mL dilution and warm the beaker gently for 15 
min. to dissolve any precipitated or residue material. Allow to cool, 
wash down the watch glass and beaker walls with deionized distilled 
water and filter the sample to remove insoluble material that could clog 
the nebulizer. (See Note 4.) Adjust the volume based on the expected 
concentrations of elements present. This volume will vary depending on 
the elements to be determined (See Note 6). The sample is now ready for 
analysis. Concentrations so determined shall be reported as 
``suspended.''

    Note: 4. In place of filtering, the sample after diluting and mixing 
may be centrifuged or allowed to settle by gravity overnight to remove 
insoluble material.

    9.3  For the determination of total elements, choose a measured 
volume of the well mixed acid preserved sample appropriate for the 
expected level of elements and transfer to a Griffin beaker. (See Note 
5.) Add 3 mL of conc. HNO3. Place the beaker on a hot plate and 
evaporate to near dryness cautiously, making certain that the sample 
does not boil and that no area of the bottom of the beaker is allowed to 
go dry. Cool the beaker and add another 5 mL portion of conc. HNO3. 
Cover the beaker with a watch glass and return to the hot plate. 
Increase the temperature of the hot plate so that a gently reflux action 
occurs. Continue heating, adding additional acid as necessary, until the 
digestion is complete (generally indicated when the digestate is light 
in color or does not change in appearance with continued refluxing.) 
Again, evaporate to near dryness and cool the beaker. Add 10 mL of 1+1 
HCl and 15 mL of deionized, distilled water per 100 mL of final solution 
and warm the beaker gently for 15 min. to dissolve any precipitate or 
residue resulting from evaporation. Allow to cool, wash down the beaker 
walls and watch glass with deionized distilled water and filter the 
sample to remove insoluble material that could clog the nebulizer. (See 
Note 4.) Adjust the sample to a predetermined volume based on the 
expected concentrations of elements present. The sample is now ready for 
analysis (See Note 6). Concentrations so determined shall be reported as 
``total.''

    Note: 5. If low determinations of boron are critical, quartz 
glassware should be used.

    Note: 6. If the sample analysis solution has a different acid 
concentration from that given in 9.4, but does not introduce a physical 
interference or affect the analytical result, the same calibration 
standards may be used.

    9.4  For the determination of total recoverable elements, choose a 
measured volume of a well mixed, acid preserved sample appropriate for 
the expected level of elements and transfer to a Griffin beaker. (See 
Note 5.) Add 2 mL of (1+1) HNO3 and 10 mL of (1+1) HCl to the 
sample and heat on a steam bath

[[Page 273]]

or hot plate until the volume has been reduced to near 25 mL making 
certain the sample does not boil. After this treatment, cool the sample 
and filter to remove insoluble material that could clog the nebulizer. 
(See Note 4.) Adjust the volume to 100 mL and mix. The sample is now 
ready for analysis. Concentrations so determined shall be reported as 
``total.''

                              10. Procedure

    10.1  Set up instrument with proper operating parameters established 
in Section 6.2. The instrument must be allowed to become thermally 
stable before beginning. This usually requires at least 30 min. of 
operation prior to calibration.
    10.2  Initiate appropriate operating configuration of computer.
    10.3  Profile and calibrate instrument according to instrument 
manufacturer's recommended procedures, using the typical mixed 
calibration standard solutions described in Section 7.4. Flush the 
system with the calibration blank (7.5.1) between each standard. (See 
Note 7.) (The use of the average intensity of multiple exposures for 
both standardization and sample analysis has been found to reduce random 
error.)

    Note: 7. For boron concentrations greater than 500 g/L 
extended flush times of 1 to 2 minutes may be required.

    10.4  Before beginning the sample run, reanalyze the highest mixed 
calibration standard as if it were a sample. Concentration values 
obtained should not deviate from the actual values by more than 
5 percent (or the established control limits whichever is 
lower). If they do, follow the recommendations of the instrument 
manufacturer to correct for this condition.
    10.5  Begin the sample run flushing the system with the calibration 
blank solution (7.5.1) between each sample. (See Note 7.) Analyze the 
instrument check standard (7.6.1) and the calibration blank (7.5.1) each 
10 samples.
    10.6  If it has been found that methods of standard addition are 
required, the following procedure is recommended.
    10.6.1  The standard addition technique (14.2) involves preparing 
new standards in the sample matrix by adding known amounts of standard 
to one or more aliquots of the processed sample solution. This technique 
compensates for a sample constitutent that enhances or depresses the 
analyte signal thus producing a different slope from that of the 
calibration standards. It will not correct for additive interference 
which causes a baseline shift. The simplest version of this technique is 
the single-addition method. The procedure is as follows. Two identical 
aliquots of the sample solution, each of volume Vx, are taken. To 
the first (labeled A) is added a small volume Vs of a standard 
analyte solution of concentration cs. To the second (labeled B) is 
added the same volume Vs of the solvent. The analytical signals of 
A and B are measured and corrected for nonanalyte signals. The unknown 
sample concentration cx is calculated:

                                                                        
                                          SBVscs                        
                                   cx= ------------                     
                                        (SA-SB) Vx                      
                                                                        

where SA and SB are the analytical signals (corrected for the 
blank) of solutions A and B, respectively. Vs and cs should be 
chosen so that SA is roughly twice SB on the average. It is 
best if Vs is made much less than Vx, and thus cs is much 
greater than cx, to avoid excess dilution of the sample matrix. If 
a separation or concentration step is used, the additions are best made 
first and carried through the entire procedure. For the results from 
this technique to be valid, the following limitations must be taken into 
consideration:
    1. The analytical curve must be linear.
    2. The chemical form of the analyte added must respond the same as 
the analyte in the sample.
    3. The interference effect must be constant over the working range 
of concern.
    4. The signal must be corrected for any additive interference.

                             11. Calculation

    11.1  Reagent blanks (7.5.2) should be subtracted from all samples. 
This is particularly important for digested samples requiring large 
quantities of acids to complete the digestion.
    11.2  If dilutions were performed, the appropriate factor must be 
applied to sample values.
    11.3  Data should be rounded to the thousandth place and all results 
should be reported in mg/L up to three significant figures.

                   12. Quality Control (Instrumental)

    12.1  Check the instrument standardization by analyzing appropriate 
quality control check standards as follow:
    12.1.1  Analyze and appropriate instrument check standard (7.6.1) 
containing the elements of interest at a frequency of 10%. This check 
standard is used to determine instrument drift. If agreement is not 
within 5% of the expected values or within the established 
control limits, whichever is lower, the analysis is out of control. The 
analysis should be terminated, the problem corrected, and the instrument 
recalibrated.

[[Page 274]]

    Analyze the calibration blank (7.5.1) at a frequency of 10%. The 
result should be within the established control limits of 2 standard 
deviations of the meal value. If not, repeat the analysis two more times 
and average the three results. If the average is not wihin the control 
limit, terminate the analysis, correct the problem and recalibrate the 
instrument.
    12.1.2  To verify interelement and background correction factors 
analyze the interference check sample (7.6.2) at the beginning, end, and 
at periodic intervals throughout the sample run. Results should fall 
within the established control limits of 1.5 times the standard 
deviation of the mean value. If not, terminate the analysis, correct the 
problem and recalibrate the instrument.
    12.1.3   A quality control sample (7.6.3) obtained from an outside 
source must first be used for the initial verification of the 
calibration standards. A fresh dilution of this sample shall be analyzed 
every week thereafter to monitor their stability. If the results are not 
within 5% of the true value listed for the control sample, 
prepare a new calibration standard and recalibrate the instrument. If 
this does not correct the problem, prepare a new stock standard and a 
new calibration standard and repeat the calibration.

                       13. Precision and Accuracy

    13.1  An interlaboratory study of metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of the twenty-five elements 
listed in Table 4 were added to reagent water, surface water, drinking 
water and three effluents. These samples were digested by both the total 
digestion procedure (9.3) and the total recoverable procedure (9.4). 
Results for both digestions for the twenty-five elements in reagent 
water are given in Table 4; results for the other matrices can be found 
in Reference 14.10.

                             14. References

    14.1  Winge, R.K., V.J. Peterson, and V.A. Fassel, ``Inductively 
Coupled Plasma-Atomic Emission Spectroscopy: Prominent Lines, EPA-600/4-
79-017.
    14.2  Winefordner, J.D., ``Trace Analysis: Spectroscopic Methods for 
Elements,'' Chemical Analysis, Vol, 46, pp. 41-42.
    14.3  Handbook for Analytical Quality Control in Water and 
Wastewater Laboratories, EPA-600/4-79-019.
    14.4  Garbarino, J.R. and Taylor, H.E., ``An Inductively-Coupled 
Plasma Atomic Emission Spectrometric Method for Routine Water Quality 
Testing,'' Applied Spectroscopy 33, No. 3 (1979).
    14.5  ``Methods for Chemical Analysis of Water and Wastes,'' EPA-
600/4-79-020.
    14.6  Annual Book of ASTM Standards, Part 31.
    14.7  ``Carcinogens--Working With Carcinogens,'' Department of 
Health, Education, and Welfare, Public Health Service, Center for 
Disease Control, National Institute for Occupational Safety and Health, 
Publication No. 77-206, August 1977.
    14.8  ``OSHA Safety and Health Standards, General Industry,'' (29 
CFR Part 1910), Occupational Safety and Health Administration, OSHA 
2206, (Revised, January 1976).
    14.9  ``Safety in Academic Chemistry Laboratories, American Chemical 
Society Publication, Committee on Chemical Safety, 3rd Edition, 1979.
    14.10  Maxfield R. and Minak B., ``EPA Method Study 27, Method 200.7 
Trace Metals by ICP,'' National Technical Information Service, Order No. 
PB 85-248-656, November 1983.

Table 1--Recommended Wavelengths\1\ and Estimated Instrumental Detection
                                 Limits                                 
------------------------------------------------------------------------
                                                              Estimated 
                                                              detection 
                    Element                     Wavelength,     limit,  
                                                     nm      g/
                                                                  L2    
------------------------------------------------------------------------
Aluminum......................................     308.215          45  
Arsenic.......................................     193.696          53  
Antimony......................................     206.833          32  
Barium........................................     455.403           2  
Beryllium.....................................     313.042           0.3
Boron.........................................     249.773           5  
Cadmium.......................................     226.502           4  
Calcium.......................................     317.933          10  
Chromium......................................     267.716           7  
Cobalt........................................     228.616           7  
Copper........................................     324.754           6  
Iron..........................................     259.940           7  
Lead..........................................     220.353          42  
Magnesium.....................................     279.079          30  
Manganese.....................................     257.610           2  
Molybdenum....................................     202.030           8  
Nickel........................................     231.604          15  
Potassium.....................................     766.491           3  
Selenium......................................     196.026          75  
Silica (SiO2).................................     288.158          58  
Silver........................................     328.068           7  
Sodium........................................     588.995          29  
Thallium......................................     190.864          40  
Vanadium......................................     292.402           8  
Zinc..........................................     213.856           2  
------------------------------------------------------------------------
\1\The wavelengths listed are recommended because of their sensitivity  
  and overall acceptance. Other wavelengths may be substituted if they  
  can provide the needed sensitivity and are treated with the same      
  corrective techniques for spectral interference. (See 5.1.1).         
\2\The estimated instrumental detection limits as shown are taken from  
  ``Inductively Coupled Plasma-Atomic Emission Spectroscopy-Prominent   
  Lines,'' EPA-600/4-79-017. They are given as a guide for an           
  instrumental limit. The actual method detection limits are sample     
  dependent and may vary as the sample matrix varies.                   
\3\Highly dependent on operating conditions and plasma position.        


[[Page 275]]


                                                Table 1--Analyte Concentration Equivalents (mg/L) Arising From Interferents at the 100 mg/L Level                                               
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                 Interferent--                                                  
                             Analyte                              Wavelength, ------------------------------------------------------------------------------------------------------------------
                                                                       nm          A1          Ca         Cr          Cu         Fe          Mg          Mn         Ni         Ti          V    
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Aluminum........................................................     308.214   ..........  .........  ..........  .........  ..........  ..........       0.21  .........  .........        1.4 
Antimony........................................................     206.833      0.47     .........        2.9   .........       0.08   ..........  .........  .........       0.25        0.45
Arsenic.........................................................     193.696      1.3      .........        0.44  .........  ..........  ..........  .........  .........  .........        1.1 
Barium..........................................................     455.403   ..........  .........  ..........  .........  ..........  ..........  .........  .........  .........  ..........
Beryllium.......................................................     313.042   ..........  .........  ..........  .........  ..........  ..........  .........  .........       0.04        0.05
Boron...........................................................     249.773      0.04     .........  ..........  .........       0.32   ..........  .........  .........  .........  ..........
Cadmium.........................................................     226.502   ..........  .........  ..........  .........       0.03   ..........  .........       0.02  .........  ..........
Calcium.........................................................     317.933   ..........  .........        0.08  .........       0.01        0.01        0.04  .........       0.03        0.03
Chromium........................................................     267.716   ..........  .........  ..........  .........       0.003  ..........       0.04  .........  .........        0.04
Cobalt..........................................................     228.616   ..........  .........        0.03  .........       0.005  ..........  .........       0.03       0.15  ..........
Copper..........................................................     324.754   ..........  .........  ..........  .........       0.003  ..........  .........  .........       0.05        0.02
Iron............................................................     259.940   ..........  .........  ..........  .........  ..........  ..........       0.12  .........  .........  ..........
Lead............................................................     220.353      0.17     .........  ..........  .........  ..........  ..........  .........  .........  .........  ..........
Magnesium.......................................................     279.079   ..........       0.02        0.11  .........       0.13   ..........       0.25  .........       0.07        0.12
Manganese.......................................................     257.610      0.005    .........        0.01  .........       0.002       0.002  .........  .........  .........  ..........
Molybdenum......................................................     202.030      0.05     .........  ..........  .........       0.03   ..........  .........  .........  .........  ..........
Nickel..........................................................     231.604   ..........  .........  ..........  .........  ..........  ..........  .........  .........  .........  ..........
Selenium........................................................     196.026      0.23     .........  ..........  .........       0.09   ..........  .........  .........  .........  ..........
Silicon.........................................................     288.158   ..........  .........        0.07  .........  ..........  ..........  .........  .........  .........        0.01
Sodium..........................................................     588.995   ..........  .........  ..........  .........  ..........  ..........  .........  .........       0.08  ..........
Thallium........................................................     190.864      0.30     .........  ..........  .........  ..........  ..........  .........  .........  .........  ..........
Vanadium........................................................     292.402   ..........  .........        0.05  .........       0.005  ..........  .........  .........       0.02  ..........
Zinc............................................................     213.856   ..........  .........  ..........       0.14  ..........  ..........  .........       0.29  .........  ..........
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------


[[Page 276]]


     Table 3--Interferent and Analyte Elemental Concentrations Used for Interference Measuremelts in Table 2    
----------------------------------------------------------------------------------------------------------------
                          Analytes         (mg/L)                  Interferents       (mg/L)                    
----------------------------------------------------------------------------------------------------------------
                    Al..................        10             Al..................     1,000  .................
                    AS..................        10             Ca..................     1,000  .................
                    B...................        10             Cr..................       200  .................
                    Ba..................         1             Cu..................       200  .................
                    Be..................         1             Fe..................     1,000  .................
                    Ca..................         1             Mg..................     1,000  .................
                    Cd..................        10             Mn..................       200  .................
                    Co..................         1             Ni..................       200                   
                    Cr..................         1             Ti..................       200                   
                    Cu..................         1             V...................       200  .................
                    Fe..................         1                                                              
                    Mg..................         1                                                              
                    Mn..................         1                                                              
                    Mo..................        10                                                              
                    Na..................        10                                                              
                    Ni..................        10                                                              
                    Pb..................        10                                                              
                    Sb..................        10                                                              
                    Se..................        10                                                              
                    Si..................         1                                                              
                    Tl..................        10                                                              
                    V...................         1                                                              
                    Zn..................        10                                                              
----------------------------------------------------------------------------------------------------------------


                                    Table 4--ICP Precision and Recovery Data                                    
----------------------------------------------------------------------------------------------------------------
                                                  Concentration    Total digestion (9.3)   Recoverable digestion
                    Analyte                       g/L         g/L         (9.4) g/L  
----------------------------------------------------------------------------------------------------------------
Aluminum......................................           69-4792     X=0.9273(C)+3.6         X=0.9380(C)+22.1   
                                                                     S=0.0559(X)+18.6        S=0.0873(X)+31.7   
                                                                    SR=0.0507(X)+3.5        SR=0.0481(X)+18.8   
Antimony......................................           77-1406     X=0.7940(C)-17.0        X=0.8908(C)+0.9    
                                                                     S=0.1556(X)-0.6         S=0.0982(X)+8.3    
                                                                    SR=0.1081(X)+3.9        SR=0.0682(X)+2.5    
Arsenic.......................................           69-1887     X=1.0437(C)-12.2        X=1.0175(C)+3.9    
                                                                     S=0.1239(X)+2.4         S=0.1288(X)+6.1    
                                                                    SR=0.0874(X)+6.4        SR=0.0643(X)+10.3   
Barium........................................             9-377     X=0.7683(C)+0.47        X=0.8380(C)+1.68   
                                                                     S=0.1819(X)+2.78        S=0.2540(X)+0.30   
                                                                    SR=0.1285(X)+2.55       SR=0.0826(X)+3.54   
Beryllium.....................................            3-1906     X=0.9629(C)+0.05        X=1.0177(C)-0.55   
                                                                     S=0.0136(X)+0.95        S=0.0359(X)+0.90   
                                                                    SR=0.0203(X)-0.07       SR=0.0445(X)-0.10   
Boron.........................................           19-5189     X=0.8807(C)+9.0         X=0.9676(C)+18.7   
                                                                     S=0.1150(X)+14.1        S=0.1320(X)+16.0   
                                                                    SR=0.0742(X)+23.2       SR=0.0743(X)+21.1   
Cadmium.......................................            9-1943     X=0.9874(C)-0.18        X=1.0137(C)-0.65   
                                                                      S=0.557(X)+2.02        S=0.0585(X)+1.15   
                                                                    SR=0.0300(X)+0.94        SR=0.332(X)+0.90   
Calcium.......................................          17-47170     X=0.9182(C)-2.6         X=0.9658(C)+0.8    
                                                                     S=0.1228(X)+10.1        S=0.0917(X)+6.9    
                                                                    SR=0.0189(X)+3.7        SR=0.0327(X)+10.1   
Chromium......................................           13-1406     X=0.9544(C)+3.1         X=1.0049(C)-1.2    
                                                                     S=0.0499(X)+4.4         S=0.0698(X)+2.8    
                                                                    SR=0.0009(X)+7.9        SR=0.0571(X)+1.0    
Cobalt........................................           17-2340     X=0.9209(C)-4.5         X=0.9278(C)-1.5    
                                                                     S=0.0436(X)+3.8         S=0.0498(X)+2.6    
                                                                    SR=0.0428(X)+0.5        SR=0.0407(X)+0.4    
Copper........................................            8-1887     X=0.9297(C)-0.30        X=0.9647(C)-3.64   
                                                                     S=0.0442(X)+2.85        S=0.0497(X)+2.28   
                                                                    SR=0.0128(X)+2.53       SR=0.0406(X)+0.96   
Iron..........................................           13-9359     X=0.8829(C)+7.0         X=0.9830(C)+5.7    
                                                                     S=0.0683(X)+11.5        S=0.1024(X)+13.0   
                                                                    SR=0.0046(X)+10.0       SR=0.0790(X)+11.5   
Lead..........................................           42-4717     X=0.9699(C)-2.2         X=1.0056(C)+4.1    
                                                                     S=0.0558(X)+7.0         S=0.0779(X)+4.6    
                                                                    SR=0.0353(X)+3.6        SR=0.0448(X)+3.5    
Magnesium.....................................          34-13868     X=0.9881(C)-1.1         X=0.9879(C)+2.2    
                                                                     S=0.0607(C)+11.6        S=0.0564(X)+13.2   

[[Page 277]]

                                                                                                                
                                                                    SR=0.0298(X)+0.6        SR=0.0268(X)+8.1    
Manganese.....................................            4-1887     X=0.9417(C)+0.13        X=0.9725(C)+0.07   
                                                                     S=0.0324(X)+0.88        S=0.0557(X)+0.76   
                                                                    SR=0.0153(X)+0.91       SR=0.0400(X)+0.82   
Molybdenum....................................           17-1830     X=0.9682(C)+0.1         X=0.9707(C)-2.3    
                                                                     S=0.0618(X)+1.6         S=0.0811(X)+3.8    
                                                                    SR=0.0371(X)+2.2        SR=0.0529(X)+2.1    
Nickel........................................          17-47170     X=0.9508(C)+0.4         X=0.9869(C)+1.5    
                                                                     S=0.0604(X)+4.4         S=0.0526(X)+5.5    
                                                                    SR=0.0425(X)+3.6        SR=0.0393(X)+2.2    
Potassium.....................................         347-14151     X=0.8669(C)-36.4        X=0.9355(C)-183.1  
                                                                     S=0.0934(X)+77.8        S=0.0481(X)+177.2  
                                                                    SR=0.0099(X)+144.2      SR=0.0329(X)+60.9   
Selenium......................................           69-1415     X=0.9363(C)-2.5         X=0.9737(C)-1.0    
                                                                     S=0.0855(X)+17.8        S=0.1523(X)+7.8    
                                                                    SR=0.0284(X)+9.3        SR=0.0443(X)+6.6    
Silicon.......................................          189-9434     X=0.5742(C)-35.6        X=0.9737(C)-60.8   
                                                                     S=0.4160(X)+37.8        S=0.3288(X)+46.0   
                                                                    SR=0.1987(X)+8.4        SR=0.2133(X)+22.6   
Silver........................................             8-189     X=0.4466(C)+5.07        X=0.3987(C)+8.25   
                                                                     S=0.5055(X)-3.05        S=0.5478(X)-3.93   
                                                                    SR=0.2086(X)-1.74       SR=0.1836(X)-0.27   
Sodium........................................          35-47170     X=0.9581(C)+39.6        X=1.0526(C)+26.7   
                                                                     S=0.2097(X)+33.0        S=0.1473(X)+27.4   
                                                                    SR=0.0280(X)+105.8      SR=0.0884(X)+50.5   
Thallium......................................           79-1434     X=0.9020(C)-7.3         X=0.9238(C)+5.5    
                                                                     S=0.1004(X)+18.3        S=0.2156(X)+5.7    
                                                                    SR=0.0364(X)+11.5       SR=0.0106(X)+48.0   
Vanadium......................................           13-4698     X=0.9615(C)-2.0         X=0.9551(C)+0.4    
                                                                     S=0.0618(X)+1.7         S=0.0927(X)+1.6    
                                                                    SR=0.0220(X)+0.7        SR=0.0472(X)+0.5    
Zinc..........................................            7-7076     X=0.9356(C)-0.30        X=0.9500(C)+1.82   
                                                                     S=0.0914(X)+3.75        S=0.0597(X)+6.50   
                                                                    SR=0.0130(X)+10.7       SR=0.0153(X)+7.78   
----------------------------------------------------------------------------------------------------------------
 AAAAAX=Mean Recovery, g/L                                                                             
 AAAAAC=True Value for the Concentration, g/L                                                          
 AAAAAS=Multi-laboratory Standard Deviation, g/L                                                       
SR=Single-analyst Standard Deviation, g/L                                                              
                                                                                                                


[49 FR 43431, Oct. 26, 1984; 50 FR 695, 696, Jan. 4, 1985, as amended at 
51 FR 23703, June 30, 1986; 55 FR 33440, Aug. 15, 1990]

  

 Appendix D to Part 136--Precision and Recovery Statements for Methods 
                          for Measuring Metals

    Twenty-eight selected methods from ``Methods for Chemical Analysis 
of Water and Wastes,'' EPA-600/4-79-020 (1979) have been subjected to 
interlaboratory method validation studies. The following precision and 
recovery statements are presented in this appendix and incorporated into 
part 136:

                              Method 202.1

    For Aluminum, Method 202.1 (Atomic Absorption, Direct Aspiration) 
replace the Precision and Accuracy Section with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water and a natural water or effluent of the analyst's choice. 
The digestion procedure was not specified. Results for the reagent water 
are given below. Results for other water types and study details are 
found in ``USEPA Method Study 7, Analyses for Trace Methods in water by 
Atomic Absorption Spectroscopy (Direction Aspiration) and Colorimetry'', 
National Technical Information Service, 5285 Port Royal Road, 
Springfield, VA 22161, Order No. PB86-208709/AS, Winter, J.A. and 
Britton, P.W., June, 1986.
    For a concentration range of 500-1200 g/L

X=0.979(C)+6.16

[[Page 278]]

S=0.066(X)+125
SR=0.086(X)+40.5

Where:

C=True Value for the Concentration, g/L
X=Mean Recovery, g/L
S=Multi-laboratory Standard Deviation, g/L
SR=Single-analyst Standard Deviation, g/L

                              Method 206.4

    For Arsenic, Method 206.4 (Spectrophotometric-SDDC) add the 
following to the Precision and Accuracy Section:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water and a natural water or effluent of the analyst's choice. 
Results for the reagent water are given below. Results for other water 
types and study details are found in ``USEPA Method Study 7, Analyses 
for Trace Methods in Water by Atomic Absorption Spectroscopy (Direct 
Aspiration) and Colorimetry'', National Technical Information Service, 
5285 Port Royal Road, Springfield, VA 22161, Order No. PB86-208709/AS, 
Winter, J.A. and Britton, P.W., June, 1986.
    For a concentration range of 20-292 g/L

X=0.850(C)-0.25
S=0.198(X)+5.93
SR=0.122(X)+3.10

Where:

C=True Value for the Concentration, g/L
X=Mean Recovery, g/L
S=Multi-laboratory Standard Deviation, g/L
SR=Single-analyst Standard Deviation, g/L

                              Method 213.1

    For Cadmium, Method 213.1 (Atomic Absorption, Direct Aspiration) 
replace the Precision and Accuracy Section with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water and a natural water or effluent of the analyst's choice. 
The digestion procedure was not specified. Results for the reagent water 
are given below. Results for other water types and study details are 
found in ``USEPA Method Study 7, Analyses for Trace Methods in Water by 
Atomic Absorption Spectroscopy (Direct Aspiration) and Colorimetry'', 
National Technical Information Service, 5285 Port Royal Road, 
Springfield, VA 22161, Order No. PB86-208709/AS, Winter, J.A. and 
Britton, P.W., June, 1986.
    For a concentration range of 14-78 g/L

X=0.919(C)+2.97
S=0.108(X)+5.08
SR=0.120(X)+0.89

Where:

C=True Value for the Concentration, g/L
X=Mean Recovery, g/L
S=Multi-laboratory Standard Deviation, g/L
SR=Single-analyst Standard Deviation, g/L

                              Method 218.1

    For Chromium, Method 218.1 (Atomic Absorption, Direct Aspiration) 
replace the Precision and Accuracy Section with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water and a natural water or effluent of the analyst's choice. 
The digestion procedure was not specified. Results for the reagent water 
are given below. Results for other water types and study details are 
found in ``USEPA Method Study 7, Analyses for Trace Methods in Water by 
Atomic Absorption Spectroscopy (Direct Aspiration) and Colorimetry'', 
National Technical Information Service, 5285 Port Royal Road, 
Springfield, VA 22161, Order No. PB86-208709/AS, Winter, J.A. and 
Britton, P.W., June 1986.
    For a concentration range of 74-407 g/L

X=0.976(C)+3.94
S=0.131(X)+4.26
SR=0.052(X)+3.01

Where:

C=True Value for the Concentration, g/L
X=Mean Recovery, g/L
S=Multi-laboratory Standard Deviation, g/L
SR=Single-analyst Standard Deviation, g/L

                              Method 220.1

    For Copper, Method 220.1 (Atomic Absorption, Direct Aspiration) 
replace the Precision and Accuracy Section with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the

[[Page 279]]

Quality Assurance Branch (QAB) of the Environmental Monitoring Systems 
Laboratory--Cincinnati (EMSL-CI). Synthetic concentrates containing 
various levels of this element were added to reagent water and a natural 
water or effluent of the analyst's choice. The digestion procedure was 
not specified. Results for the reagent water are given below. Results 
for other water types and study details are found in ``USEPA Method 
Study 7, Analyses for Trace Methods in Water by Atomic Absorption 
Spectroscopy (Direct Aspiration) and Colorimetry'', National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161, Order 
No. PB86-208709/AS, Winter, J.A. and Britton, P.W., June, 1986.
    For concentration range 60-332 g/L
X=0.963(C)+3.49
S=0.047(X)+12.3
SR=0.042(X)+4.60

Where:

C=True Value for the Concentration, g/L
X=Mean Recovery, g/L
S=Multi-laboratory Standard Deviation, g/L
SR=Single-analyst Standard Deviation, g/L

                              Method 236.1

    For Iron, Method 236.1 (Atomic Absorption, Direct Aspiration) 
replace the Precision and Accuracy Section with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water and a natural water or effluent of the analyst's choice. 
The digestion procedure was not specified. Results for the reagent water 
are given below. Results for other water types and study details are 
found in ``USEPA Method Study 7, Analyses for Trade Methods in Water by 
Atomic Absorption Spectroscopy (Direct Aspiration) and Colorimetry'', 
National Technical Information Service, 5285 Port Royal Road, 
Springfield, VA 22161, Order No. PB86-208709/AS, Winter, J.A. and 
Britton, P.W., June, 1986.
    For concentration range 350-840 g/L

X=0.999(C)-2.21
S=0.022(X)+41.0
SR=0.019(X)+21.2

Where:

C=True Value for the Concentration, g/L
X=Mean Recovery, g/L
S=Multi-Laboratory Standard Deviation, g/L
SR=Single-analyst Standard Deviation, g/L

                              Method 239.1

    For Lead, Method 239.1 (Atomic Absorption, Direct Aspiration) 
replace Precision and Accuracy Section with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water and a natural water or effluent of the analyst's choice. 
The digestion procedure was not specified. Results for the reagent water 
are given below. Results for other water types and study details are 
found in ``USEPA Method Study 7 Analyses for Trace Methods in Water by 
Atomic Absorption Spectroscopy (Direct Aspiration) and Colorimetry''; 
National Technical Information Service, 5285 Port Royal Road, 
Springfield, VA 22161, Order No. PB86-208709/AS, Winter, J.A. and 
Britton, P.W., June, 1986.
    For concentration range of 84-367 g/L

X=0.961(C)+13.8
S=0.028(C)+33.9
SR=0.011(X)+16.1

Where:

C=True Value for the Concentration, g/L
X=Mean Recovery, g/L
S=Multi-laboratory Standard Deviation, g/L
SR=Single-analyst Standard Deviation, g/L

                              Method 243.1

    For Manganese, Method 243.1 (Atomic Absorption, Direct Aspiration) 
replace Precision and Accuracy Section with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water and a natural water or effluent of the analyst's choice. 
The digestion procedure was not specified. Results for the reagent water 
are given below. Results for other water types and study details are 
found in ``USEPA Method Study 7, Analyses for Trace Methods in Water by 
Atomic Absorption Spectroscopy (Direct Aspiration) and Colorimetry'', 
National Technical Information Service, 5285 Port Royal Road, 
Springfield, VA 22161, Order No. PB86-208709/AS, Winter, J.A. and 
Britton, P.W., June, 1986.
    For concentration range 84-469 g/L

X=0.987(C)-1.27

[[Page 280]]

S=0.042(X)+8.95
SR=0.023(X)+4.90

Where:

C=True Value for the Concentration, g/L
X=Mean Recovery, g/L
S=Multi-laboratory Standard Deviation, g/L
SR=Single-analyst Standard Deviation, g/L

                              Method 289.1

    For Zinc, Method 289.1 (Atomic Absorption, Direct Aspiration) 
replace the Precision and Accuracy Section with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory-Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water and a natural water or effluent of the analyst's choice. 
The digestion procedure was not specified. Results for the reagent water 
are given below. Results for other water types and study details are 
found in ``USEPA Method Study 7, Analyses for Trace Methods in Water by 
Atomic Absorption Spectroscopy (Direct Aspiration) and Colorimetry'', 
National Technical Information Service, 5285 Port Royal Road, 
Springfield, VA 22161, Order No. PB86-208709/AS, Winter, J. A. and 
Britton, P. W., June, 1986.

For concentration range 56-310 g/L
    X=0.999(C)+0.033
    S=0.078(X)+10.8
    SR=0.049(X)+1.10

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation, g/L

                              Method 202.2

    For Aluminum, Method 202.2 (Atomic Absorption, Furnace Technique) 
replace the Precision and Accuracy Section statement with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory-Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual. Results for the reagent water are given below. Results for other 
water types and study details are found in ``EPA Method Study 31, Trace 
Metals by Atomic Absorption (Furnace Techniques), ``National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161, Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 0.46-125 g/L
    X=1.1579(C)-0.121
    S=0.4286(X)-0.124
    SR=0.2908(X)-0.082

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation, g/L

                              Method 204.2

    For Antimony, Method 204.2 (Atomic Absorption, Furnace Technique) 
replace the Precision and Accuracy Section statement with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory-Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual as modified by this method. Results for the reagent water are 
given below. Results for other water types and study details are found 
in ``EPA Method Study 31, Trace Metals by Atomic Absorption (Furnace 
Techniques),'' National Technical Information Service, 5285 Port Royal 
Road, Springfield, VA 22161, Order No. PB 86-121 704/AS, by Copeland, 
F.R. and Maney, J.P., January 1986.

For a concentration range of 10.50-240 g/L
    X=0.7219(C)-0.986
    S=0.3732(X)+0.854
    SR=0.1874(X)-0.461

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation, g/L

                              Method 206.2

    For Arsenic, Method 206.2 (Atomic Absorption, Furnace Technique) add 
the following to the existing Precision and Accuracy statement:

[[Page 281]]

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory-Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. 
Results for the reagent water are given below. Results for other water 
types and study details are found in ``EPA Method Study 31, Trace Metals 
by Atomic Absorption (Furnace Techniques),'' National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161, Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 9.78-237 g/L
    X=0.9652(C)+2.112
    S=0.1411(X)+1.873
    SR=0.0464(X)+2.109

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation, g/L

                              Method 208.2

    For Barium, Method 208.2 (Atomic Absorption, Furnace Technique) add 
the following to the existing Precision and Accuracy information:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual. Results for the reagent water are given below. Results for other 
water types and study details are found in ``EPA Method Study 31, Trace 
Metals by Atomic Absorption (Furnace Techniques),'' National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161, Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 56.50-437 g/L
    X=0.8268(C)+59.459
    S=0.2466(X)+6.436
    SR=0.1393(X)-0.428

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation, g/L

                              Method 210.2

    For Beryllium, Method 210.2 (Atomic Absorption, Furnace Technique) 
replace the existing Precision and Accuracy statement with the 
following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual. Results for the reagent water are given below. Results for other 
water types and study details are found in ``EPA Method Study 31, Trace 
Metals by Atomic Absorption (Furnace Techniques),'' National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161, Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 0.45-11.4 g/L
    X=1.0682(C)-0.158
    S=0.2167(X)+0.090
    SR=0.1096(X)+0.061

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation, g/L

                              Method 213.2

    For Cadmium, Method 213.2 (Atomic Absorption, Furnace Technique) add 
the following to the existing Precision and Accuracy information:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring System Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual. Results for the reagent water are given below. Results for other 
water types and study details are found in ``EPA Method Study 31,

[[Page 282]]

Trace Metals by Atomic Absorption (Furnace Techniques),'' National 
Technical Information Service, 5285 Port Royal Road, Springfield, VA 
22161, Order No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., 
January 1986.

For a concentration range of 0.43-12.5 g/L
    X=0.9826(C)+0.171
    S=0.2300(X)+0.045
    SR=0.1031(X)+0.116

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Devision, g/L

                              Method 218.2

    For Chromium, Method 218.2 (Atomic Absorption, Furnace Technique) 
add the following to the existing Precision and Accuracy Section:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual. Results for the reagent water are given below. Results for other 
water types and study details are found in ``EPA Method Study 31, Trace 
Metals by Atomic Absorption (Furnace Techniques),'' National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161, Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 9.87-246 g/L
    X=0.9120(C)+0.234
    S=0.1684(X)+0.852
    SR=0.1469(X)+0.315

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Devision, g/L

                              Method 219.2

    For Cobalt, Method 219.2 (Atomic Absorption, Furnace Technique), 
replace the Precision and Accuracy Section statement with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual. Results for the reagent water are given below. Results for other 
water types and study details are found in ``EPA Method Study 31, Trace 
Metals by Atomic Absorption (Furnace Techniques),'' National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161 Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 21.10-461 g/L
    X=0.8875(C)+0.859
    S=0.2481(X)-2.541
    SR=0.0969(X)+0.134

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation,  g/L

                              Method 220.2

    For Copper, Method 220.2 (Atomic Absorption, Furnace Technique) 
replace the Precision and Accuracy Section statement with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual. Results for the reagent water are given below. Results for other 
water types and study details are found in ``EPA Method Study 31, Trace 
Metals by Atomic Absorption (Furnace Techniques),'' National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161 Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 0.30-245 g/L
    X=0.9253(C)+0.010
    S=0.2735(X)-0.058
    SR=0.2197(X)-0.050

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation,  g/L

[[Page 283]]

                              Method 236.2

    For Iron, Method 236.2 (Atomic Absorption, Furnace Technique) 
replace the Precision and Accuracy Section statement with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual. Results for the reagent water are given below. Results for other 
water types and study details are found in ``EPA Method Study 31, Trace 
Metals by Atomic Absorption (Furnace Techniques),'' National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161 Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 0.37-455 g/L
    X=1.4494(C)-0.229
    S=0.3611(X)-0.079
    SR=0.3715(X)-0.161

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation,  g/L

                              Method 239.2

    For Lead, Method 239.2 (Atomic Absorption, Furnace Technique) add 
the following to the existing Precisions and Accuracy Section:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual. Results for the reagent water are given below. Results for other 
water types and study details are found in ``EPA Method Study 31, Trace 
Metals by Atomic Absorption (Furnace Techniques),'' National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161 Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 10.40-254 g/L
    X=0.9430(C)-0.504
    S=0.2224(X)+0.507
    SR=0.1931(X)-0.378

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation,  g/L

                              Method 243.2

    For Manganese, Method 243.2 (Atomic Absorption, Furnace Technique) 
replace the Precision and Accuracy Section statement with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL--CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual. Results for the reagent water are given below. Results for other 
water types and study details are found in ``EPA Method Study 31, Trace 
Metals by Atomic Absorption (Furnace Techniques),'' National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161. Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 0.42-666 g/L
    X=1.0480(C)+1.404
    S=0.2001(X)+1.042
    SR=0.1333(X)+0.680

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation, g/L

                              Method 249.2

    For Nickel, Method 249.2 (Atomic Absorption, Furnace Technique) 
replace the Precision and Accuracy Section statement with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL--CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents.

[[Page 284]]

These samples were digested by the total digestion procedure, 4.1.3 in 
this manual. Results for the reagent water are given below. Results for 
other water types and study details are found in ``EPA Method Study 31, 
Trace Metals by Atomic Absorption (Furnace Techniques),'' National 
Technical Information Service, 5285 Port Royal Road, Springfield, VA 
22161. Order No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., 
January 1986.

For a concentration range of 26.20-482 g/L
    X=0.8812(C)+2.426
    S=0.2475(X)+1.896
    SR=0.1935(X)+1.315

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation, g/L

                              Method 270.2

    For Selenium, Method 270.2 (Atomic Absorption, Furnace Technique) 
add the following to the existing Precision and Accuracy Section:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL--CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. 
Results for the reagent water are given below. Results for other water 
types and study details are found in ``EPA Method Study 31, Trace Metals 
by Atomic Absorption (Furnace Techniques),'' National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161. Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 10.00-246 g/L
    X=0.9564(C)+0.476
    S=0.1584(X)+0.878
    SR=0.0772(X)+0.547

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation, g/L

                              Method 272.2

    For Silver, Method 272.2 (Atomic Absorption, Furnace Technique) add 
the following to the existing Precision and Accuracy Section:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory--Cincinnati (EMSL--CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual. Results for the reagent water are given below. Results for other 
water types and study details are found in ``EPA Method Study 31, Trace 
Metals by Atomic Absorption (Furnace Techniques),'' National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161. Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 0.45-56.5 g/L
    X=0.9470(C)+0.181
    S=0.1805(X)+0.153
    SR=0.1417(X)+0.039

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation, g/L

                              Method 279.2

    For Thalliu, Method 279.2 (Atomic Absorption, Furnace Technique) 
replace the Precision and Accuracy Section statement with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory-Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual. Results for the reagent water are given below. Results for other 
water types and study details are found in ``EPA Method Study 31, Trace 
Metals by Atomic Absorption (Furnace Techniques),'' National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161 Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 10.00-252 g/L.
    X=0.8781(C)-0.715
    S=0.1112(X)+0.669
    SR=0.1005(X)+0.241

Where:

    C=True Value for the Concentration, g/L

[[Page 285]]

    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation, g/L

                              Method 286.2

    For Vanadium, Method 286.2 (Atomic Absorption, Furnace Technique) 
replace the Precision and Accuracy Section statement with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory-Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual. Results for the reagent water are given below. Results for other 
water types and study details are found in ``EPA Method Study 31, Trace 
Metals by Atomic Absorption (Furnace Techniques),'' National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161 Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 1.36-982 g/L.
    X=0.8486(C)+0.252
    S=0.3323(X)-0.428
    SR=0.1195(X)-0.121

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation,   g/L

                              Method 289.2

    For Zinc, Method 289.2 (Atomic Absorption, Furnace Technique) 
replace the Precision and Accuracy Section statement with the following:

                         Precision and Accuracy

    An interlaboratory study on metal analyses by this method was 
conducted by the Quality Assurance Branch (QAB) of the Environmental 
Monitoring Systems Laboratory-Cincinnati (EMSL-CI). Synthetic 
concentrates containing various levels of this element were added to 
reagent water, surface water, drinking water and three effluents. These 
samples were digested by the total digestion procedure, 4.1.3 in this 
manual. Results for the reagent water are given below. Results for other 
water types and study details are found in ``EPA Method Study 31, Trace 
Metals by Atomic Absorption (Furnace Techniques),'' National Technical 
Information Service, 5285 Port Royal Road, Springfield, VA 22161 Order 
No. PB 86-121 704/AS, by Copeland, F.R. and Maney, J.P., January 1986.

For a concentration range of 0.51-189 g/L.
    X=1.6710(C)+1.485
    S=0.6740(X)-0.342
    SR=0.3895(X)-0.384

Where:

    C=True Value for the Concentration, g/L
    X=Mean Recovery, g/L
    S=Multi-laboratory Standard Deviation, g/L
    SR=Single-analyst Standard Deviation,   g/L
[55 FR 33442, Aug. 15, 1990]