| Abstrakt: |
Soils and sediments contaminated with residues of technical toxaphene may require remedial action to reduce human health and ecological risks. Sediments were collected from a coastal wetland impacted by discharge from a former toxaphene production facility and analyzed by gas chromatography--electron capture detection and conventional and enantioselective gas chromatography--mass spectrometry in the electron capture negative ion mode. The prominent chlorobornanes (CHBs) in all samples were 2-exo,3-endo,6-exo,8,9,10-hexachlorobornane (B6-923 or Hx-Sed) and 2-endo,3-exo,5-endo,6-exo,8,9,10-heptachlorobornane (B7-1001 or Hp-Sed), metabolites of higher chlorinated components of technical toxaphene (CTTs). Pentachlorobornanes, toxaphene homologs not previously reported in environmental samples, and likely precursor CTTs were also detected. Several CHB congeners were enantioresolved, the majority of which exhibited racemic composition. These results indicate that the profile of CHBs persisting in estuarine sediment is highly modified relative to the technical mixture, and also provides strong evidence of in situ reductive dechlorination, a process that if enhanced could act to reduce bioaccumulation and toxicity of sediment-bound CTTs at toxaphenecontaminated sites. [ABSTRACT FROM AUTHOR] |
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