Correspondence Comment on “Pharmaceuticals, Hormones, and Other Organic Wastewater Contaminants in U.S. Streams, 1999-2000: A National Reconnaissance” Kolpin et al. (1) are to be commended for their survey of unusual pollutants in U.S. surface waters. The issue of pharmaceutical and other unusual compounds in surface waters and groundwaters has been emerging for some time (2) and is now receiving attention both in the United States and abroad (3). Part of the underlying problem in bringing the occurrence of such compounds to the attention of the scientific community lies in the practice of “priority pollutant” analysis. When researchers and government programs repeatedly “round up the usual suspects”, it is no wonder that frequently occurring compounds that are not priority pollutants receive too little attention. Thousands of nonpriority pollutants can be detected by techniques such as GC/MS with mass spectral library searching, but the level of effort put into reliably identifying and reporting these “tentatively identified compounds”, by both laboratories and data users is more often than not inadequate (4, 5). Several of the compounds reported by Kolpin et al. (1) have previously been reported in a database accumulated from thousands of sample analyses (ca. 1987-1989) from Superfund sites in the United States (6, 7) including DEET, phthalic anhydride, tributyl phosphate, cholesterol, triphenyl phosphate, nicotine, chlorpyrifos, caffeine, bisphenol A, and tris(2-chloroethyl)phosphate. Dozens of other compounds tentatively identified by a GC/MS library search in this database have been confirmed by the close match between their experimental PAH GC retention index (8, 9) and the median retention index from dozens to hundreds of identifications per compound in the database. Retention index analysis of tentatively identified compound data was also a key step in the work that led to the discovery of certain pharmaceuticals in groundwater (10). The compounds in these papers (6, 7, 10), which represent a wide variety of sources and uses, are also potential pollutants of surface water and groundwater. † Institutional affiliation is given for identification only; the opinions expressed are solely those of the author.
10.1021/es025709f Not subject to U.S. Copyright. Publ. 2002 Am. Chem. Soc. Published on Web 08/14/2002
The routine identification of nonpriority pollutants would benefit greatly from the use of GC retention index data in standard GC/MS methods. The scientific community has been using this approach for years; a Dialog search on April 3, 2002, yielded 404 references to the original paper in which the PAH retention index was proposed (9). No new equipment is needed; only a calculation based on retention time data that is already generated in the analysis. The use of retention index data to supplement GC/MS library searching could have considerably speeded up the recognition of nonpriority pollutants as an emerging issue and could yet lead to the identification of new emerging pollutants.
Literature Cited (1) Kolpin, D. W.; Furlong, E. T.; Meyer, M. T.; Thurman, E. M.; Zaugg, S. D.; Barber, L. B.; Buxton, H. T. Environ. Sci. Technol. 2002, 36, 1202-1211. (2) Raloff, J. Sci. News 1998, 153, 187-189 (http://www.sciencenews.org/sn_arc98/3_21_98/bob1). (3) Halling-Sørensen, B.; Nielsen, S. N.; Lanzky, P. F.; Ingerslev, F.; Holten Lu ¨ tzhøft, H. C.; Jørgensen, S. E. Chemosphere 1997, 36, 357-393. (4) Swallow, K.; Shifrin, N. S.; Doherty, P. J. Environ. Sci. Technol. 1988, 22, 136-142. (5) Eckel, W. P. Am. Lab. 2000, March, 17-20. (6) Eckel, W. P. Preprints of Papers, 208th National Meeting of the American Chemical Society, Washington, DC; American Chemical Society: Washington, DC, 1994; ENVR 215. (7) Eckel, W. P. Preprints of Papers, 208th National Meeting of the American Chemical Society, Washington, DC; American Chemical Society: Washington, DC, 1994; ENVR 216. (8) Rostad, C. E.; Pereira, W. E. J. High Resolut. Chromatogr. Chromatogr. Commun. 1986, 9, 328-334. (9) Lee, M. L.; Vasillaros, D. L.; White, C. M.; Novotny, M. Anal. Chem. 1979, 51, 6, 768-773. (10) Eckel, W. P.; Ross, B.; Isensee, R. K. Ground Water 1993, 31, 801-804.
William P. Eckel† U.S. EPA Office of Pesticide Programs Environmental Fate and Effects Division (7507C) 1921 Jefferson Davis Highway, 10th Floor Arlington, Virginia 22202 ES025709F
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