Analysis of organic water pollutants a
A list of consensus voluntary reference compounds ( C V R C s )serves as a basis for establishing references against which variations or improvements in analytical methodology can be compared
Lawrence H. Keith Radian Corporation Austin, Texas 78766
Only recently has it become possible to identify and analyze a large variety of specific organic (nonpesticide) environmental pollutants which exist at trace levels in the presence of thousands of other organic compounds. Advances both in techniques of separation (high-resolution gas and liquid chromatography) and in methods of identification (computerized mass spectrometry and, to a lesser extent, selective detectors and Fourier transform infrared spectrophotometry) have been key factors in this achievement. The result has been a dramatic increase in the number of papers dealing with the identification and analysis of organic compounds in the environment in general. Most of the attention, however, has been focused on organics in water. An important and complex facet of this subject is the preparation of samples before instrumental analysis. Research involving sample preparation is often fragmentary by nature. Although many papers deal with the same aspect of sample preparation, they cannot be directly correlated because of differences in the samples, sample handling, and/or model compounds used.
TABLE 1
Panel members of the Council on EnvEronmental Pollutants REFRESENTINQ
NAME
Lawrence Keith (chairman) Ryoshi Ishiwatari Krister Lindstrom Harry Hertz James Lichtenberg Steven Heller Edo Pellizzari
American Chemical Society Chemical Society of Japan Swedish Chemical Society
U.S. National Bureau of Standards American Society fw Testing Materials and US. Environmental Protection Agency US. EnvironmentalProtection Agency’s “Water DROP” (Distribution Register of Organic Pollutants in Water) US. Environmental Protection Agency’s “Master Scheme”
TABLE 2
Consensus voluntary reference compounds by chemical class 1. ALCOHOLS
Ethanol P-Chloroethanol Cyclohexanol 2-Chlorocyclohexanol a-Terpineol 6. Cholesterol
1. 2. 3. 4. 5.
7. 8. 9. 10. 11.
Benzyl alcohol 3-Chlorobenzyl alcohol 2-Ethylhexanol Glucose Glycerol
11. ALDEHYDES
1. 2. 3. 4.
Acetaldehyde Benzaldehyde 3-Chlorobenzaldehyde Crotonaldehyde
5. Vanillin 6. Chloral 7. Furfural
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This became apparent when the first major symposium involving the identification and analysis of organic pollutants in water was held during the 1975 Chemical Congress of the North American Continent. At that meeting it was suggested that a council be organized to establish a consensus voluntary system that could be used easily as a basis for establishing references against which variations or improvements in analytical methodology could be compared.
Ill. ALIPHATICS
1. Pentane 2. n-Hexadecane 3. Cyclopentadiene 4. Hexachlorocyclopentadiene" 5. Cyclohexane 6. Chlorocyclohexane 7. &Pinene
8. Chloroform* 9. Bromoform. 10. Tetrachloroethylene" 11. 1,2-Dibromoethane 12. Heptachlor ( 1,4,5,6,7,8,8heptachloro3a,4,7,7a-Tetrahydro-4,7methanoindene)
IV. AMINES
1. Diethylamine 2. Aniline 3. 2-Chloroaniline
4. Piperidene
5. Quinoline 6. 4-Chloroquinoline
7. Benzidine'
8. 9. 10. 11.
3,3'-Dichlorobenzidene" Indole 5-Chloroindole Atrazine [2-chloro-4(ethylamin0)6-(lsopropytarnino)-striazine] 12. 36hloropyridine
V. BEMENOIDS
1. 2. 3. 4.
Benzene' Chlorobenzene* Hexachlorobenzene Bromopentafluorobenzene 5. Biphenyl 6. 4,4'-DichlorobiphenyI 7. Decachlorobiphenyl
8. 9. 10. 11. 12.
Decabromobiphenyl lndan 4-lsopropyltoluene 2,2-Diphenylpropane ~ , ~ ' - D D(Ei , i dichloro-2,2-bis(p chloropheny1)ethylene 13. 1,2,4-Trichlorobenzene"
VI. CARBOXYLIC ACIDS
Acetic acid Dichloroacetic acid Benzoic acid 4-Chlorobenzoic acid 5. Phthalic acid 6. 4-Chlorophthalic acid
1. 2. 3. 4.
7. 8. 9. 10. 11. 12.
Stearic acid TFimeSiC acid Succinic acid Phenylalanine 4-Chlorophenylalanine Dehydroabieticacid
Vll. ESTERS
The American Chemical Society's Division of Environmental Chemistry supported this concept. Subsequently, a Division steering committee was established to direct a Council on Environmental Pollutants (CEP). The first objective was to formulate a list of voluntary reference compounds that could be widely used to compare improvements in new or modified techniques with existing methodology. This objective was met by convening an international panel of environmental chemists who chose by consensus a list of model reference compounds. The recent Pacific Conference in Honolulu, sponsored by the American Chemical Society and the Chemical Society of Japan, was selected as the forum for that panel discussion. (The representatives who comprised that panel are noted in Table I ) . Panel members, as well as interested members of the audience, nominated 1470
Environmental Science & Technology
1. 2. 3. 4.
Ethyl acetate 2-Chloroethyl acetate bis(2-Ethylhexyl)phthalate* Phenyl benzoate 5. 46hlorophenyl benzoate
6. Methyl stearate 7. Methyl methacrylate 8. Methyl abietate 9. Glyceryl tripalmitate
'VIII. ETHERS
1. 2. 3. 4.
Diethyl ether bis(26hloroethyl)ether" Diphenyl ether Anisole
5. Pentachloroanisole 6. Dibenzofuran 7. 1,4-Dioxane 8. Tetrahydrofuran
IX. KETONES
1. 2. 3. 4.
Acetone lI1,3,3-Tetrachloroacetone Acetophenone 4-Ch loroacetophenone 5. Cyclohexanone 6. 2-Chlorocyclohexanone
7. 8. 9. 10. 11. 12.
Anthraquinone 2Chloroanthraquinone Methyl isobutyl ketone 9-Fluorenone Fenchone lsophorone
X. NITROGEN COMPOUNDS
Urea 1,2-Diphenylhydrazine" KNitrosodi-n-propylamine' KNitrosodiphenylamine" 5. Caprolactam 6. Nitrobenzene 7. 1,4-Nitrochlorobenzene 8. Acrylamide 9. Nitromethane
1. 2. 3. 4.
10. 11. 12. 13. 14. 15. 16. 17. 18.
Acrylonitrile* Azobenzene Caffeine Carbazole Uracil 5-Chlorouracil Uridine 5-Chlorouridine Kmethy lcarbamate
XI. ORGANOMETALLICS
1. Tetraethyl lead 2. Dimethyl mercury
3. Tetrabutyl tin 4. Ferrocene
XII. PHENOLS
1. Phenol" 2. Pentachlorophenol
3. 4-Phenylphenol 4. 4-Nitrophenol" 5. Guaiacol 6. Catechol 7. Tetrachlorocatechol
8. Bisphenol A 9. TetrabromobisphenolA IO. I-Napthol 11. 4-chloro- 1-napthol 12. 2,6-Di-tert-butyl-4methylphenol 13. 2,4-Dichlorophenol*
XIII. PHOSPHORUS COMPOUNDS
1. 2. 3. 4. 5.
Tri-n-butyl phosphate Triphenyl phosphate Triethyl phosphine Triphenyl phosphite Diethyl phosphoric acid
6. Malathion (diethyl mercaptosuccinate, s-ester of o,odimethylphosphorodithioate) 7. tris(2-Chloroethyl) phosphate 8. Leptophos [o-4-bromo2,5-dichlorophenyl) o-methyl phenylphosphonothionate]
XIV. POLYNUCLEAR AROMATICS
1. 2. 3. 4. 5.
Naphthalene* 2-Chloronaphthalene Acenaphthylene" Anthracene* Pyrene"
6. Benzo [alanthracene * 7. Benzo[a] pyrene 8. Perylene 9. Coronene 10. Fluoranthene"
XV. SULFONIC ACIDS
1. Benzenesulfonic acid 2. Methanesulfonic acid
3. 1-Naphthalenesulfonic acid
chemicals as consensus voluntary reference compounds (CVRC's). This list is presented in Table 2 and has been approved by the Executive Committee of the ACS Division of Environmental Chemistry and has been endorsed by the A C S Joint Board/Council Committee on Environmental Improvement. Known water pollutants were the prime candidates for reference compounds; the choice, however, WBS not restricted to water pollutants, for it was more important to obtain a wide variety of representative compounds. For example, relatively few water pollutants containing nitrogen and sulfur have been identified. Perhaps this is because they are not as abundant as organic pollutants that do not contain these heteroatoms. But a major contributing factor could also be that present methodology is inadequate to concentrate, fractionate, isolate and/ or detect them even if they are present. Of course, no representative list of model compounds will be completely adequate. On the basis of our present knowledge and technology, however, the C E P list of CVRC's should be adequate to handle at least 90% of projected current needs. As this list is used, we hope that constructive criticism will be forwarded to C E P so that appropriate additions and/or modifications can be made. Presently, this can best be achieved by channeling comments through Dr. Keith and the A C S Division of Environmental Chemistry. Pending the successful acceptance of this first venture by the world scientific community, other objectives of C E P will be pursued. These may i n clude, but are not limited to, similar lists of CVRC's for developing methodology related to air pollution and sediment/soil pollution (e.g., from uncontrolled chemical landfills).
4. 2,6-Naphthalenedisulfonic
acid
XVI. SULFUR COMPOUNDS (OTHER THAN SULFONIC ACIDS)
1. 2. 3. 4. 5. 6. 7.
Carbon disulfide Dimethyl disulfide Diphenyl disulfide fert-Butvl mercaPtan Dimethyl sulfone 2-Acetylthiophene Thiophenol 8. Ethylisothiocyanate
9. Dimethyl sulfoxide 10. Benzothiophene 11. 1,4-PropanesuIfone 12. a-Endosulfan" (6,7,8,g,10,10-hexachloro~ 1,5,5a, 6,9,ga-hexahydro6,9-methano-2,4,3-benzodioxathiepin-3-oxide)
* Compounds on the U.S. Environmental Protection Agency Priority Pollutant list.
Dr. Lawrence H. Keith is manager of the Analytical Chemical Division at Radian Corporation in '4ustin. Texas. He is also chairman of the A C S Division of Environmental Chemistry and, prior to joining Radian. worked for EPA at the Athens. Georgia Environmental Research Liboratory. Volume 13, Number 12, December 1979
1471
