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Article

Enantiomeric Composition of Chiral Polychlorinated Biphenyl Atropisomers in Aquatic and Riparian Biota

Charles S. Wong,^†^‡ Arthur W. Garrison,*^† Paul D. Smith,^† and William T. Foreman^§

Ecosystems Research Division, National Exposure Research Laboratory, U.S. Environmental Protection Agency, Athens Georgia 30605, and National Water Quality Laboratory, U.S. Geological Survey, P.O. Box 25046, MS 407, Denver Colorado 80225

Environ. Sci. Technol., 2001, 35 (12), pp 2448–2454

DOI: 10.1021/es0018872

Publication Date (Web): May 17, 2001

†

U.S. Environmental Protection Agency.

‡

Present address: Department of Chemistry, University of Toronto, Toronto, ON, M5S 3H6 Canada.

Corresponding author e-mail: garrison.wayne@epa.gov; phone: (706)355-8219; fax: (706)355-8202.

U.S. Geological Survey.

Abstract

The enantiomeric composition of polychlorinated biphenyl (PCB) atropisomers was measured in river and riparian biota (fish, bivalves, crayfish, water snakes, barn swallows) from selected sites throughout the United States by using chiral gas chromatography/mass spectrometry. Nonracemic enantiomeric fractions (EFs) were observed for PCBs 91, 95, 136, and 149 for aquatic and riparian biota from Lake Hartwell, SC, a reservoir heavily contaminated with PCBs, and for these congeners and PCBs 132, 174, 176, and 183 in river fish and bivalves nationwide. Fish and bivalves showed marked differences in EFs as compared to sediment found at the same sampling sites, thus suggesting that PCBs are bioprocessed in biota in a different manner from those found in sediment (e.g., reductive dechlorination). Species-dependent patterns in PCB EFs were observed, which suggest differences in the ability of different species to bioprocess PCBs enantioselectively, most likely by metabolism. The presence of nonracemic PCBs in fish and bivalves suggests greater metabolic degradation of PCBs in these organisms than indicated from previous achiral studies and underscores the powerful potential of chiral analysis as a tracer of environmental bioprocesses.

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