Enantiomer Ratios of Chlordane Congeners Are Gender Specific in Cod (Gadus morhua) from the Barents Sea

The enantiomer ratios of some chlordane congeners were found to be gender-specific in cod from the Barents Sea. Concentrations of U81, U82, trans- chlordane, MC5, cis- chlordane, MC7, trans- nonachlor, MC6, and cis- nonachlor as well as the metabolites cis- heptachlorepoxide and oxychlordane were determined. Female cod preferentially accumulated (−)- cis -chlordane and (−)- trans -chlordane, while male cod had an excess of (+)- cis -chlordane and (+)- trans -chlordane. A significant difference was also observed for MC6. Only chlordane congeners without a chlorine atom at the C3 position showed gender-specific enantiomer ratios. No exception was found within the sample set of 16 individuals. Furthermore, the isomer and enantiomer patterns were very similar in muscle tissue, gonads, and liver.