ISOMER-SELECT AND ENANTIOMER-SELECTIVE ANALYSES OF TOXAPHENE COMPONENTS USING CHIRAL HIGH-RESOLUTION GAS-CHROMATOGRAPHY AND DETECTION BY MASS-SPECTROMETRY

Achiral and chiral high-resolution gas chromatography (HRGC) in combination with electron ionization (EI) mass spectrometry/mass spectrometry (MS/MS) was used for the analysis of toxaphene components in a technical mixture and in tissue extracts of several aquatic vertebrate species collected from the Baltic Sea (herring, salmon, seal), the Arctic (seal), and the Antarctic (penguin). Enhanced isomer selectivity of some toxaphene components was obtained by selected-reaction monitoring (SRM) using ion transitions commonly not observed with other halogenated contaminants. All species showed extensive alteration of the original toxaphene mixture with only a few, but largely the same, polychlorobornanes present. Using chiral HRGC, the enantiomer resolution of several major toxaphene components was achieved. Analysis of the technical mixture revealed racemic or nearly racemic mixtures of these compounds, and analysis of the aquatic species showed some changes in enantiomeric composition for some components. However, the enantiomeric composition of the most accumulating nonachlorobornane, TOX9, was not much different in all the species, indicating little if any biological degradation of this component.