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.