Chromatographic separation of the enantiomers of marine pollutants. Part 6: Comparison of the enantioselective degradation of α-hexachlorocyclohexane in marine biota and water

Abstract

The enantiomeric ratios of the chiral marine pollutant α-hexachlorocyclohexane [α-HCH] was determined in blue mussels (Mytilus edulis L.), flounders (Platychthys flesus (L.)), Common eider ducks (Somateria mollissima (L.)), and in North Sea water of experimental sites in the German Bight by means of capillary gas chromatography using β-cyclodextrin derivatives as chiral stationary phases. Different enzymatic degradation pathways are revealed by opposite enantioselective enrichments of the α-HCH enantiomers: while in the liver of Common eider ducks the preferable degradation of (−)-α-HCH leads to an enrichment of (+)-α-HCH [i.e., (+)-α- HCH (t)-α- HCH ≈ 1.4 − ∞ ], the enantiomeric ratios measured in the liver samples of flounders [ (+)-α- HCH (t)-α- HCH ≈ 0.80 − 0.94 ], in blue mussels [ (+)-α- HCH (t)-α- HCH ≈ 0.84 − 0.93 ] and in the North Sea water samples [ (+)-α- HCH (t)-α- HCH ≈ 0.84 ] imply enzymatic processes in the course of which common structural elements are preferred represented by (+)-α-HCH.