Peak patterns of chlorostyrenes in fish and fish oils from the North Atlantic

Residues of polychlorinated styrenes have been quantified in fish from different regions of the North Atlantic and in fish oils. One penta-, three hexa-, and six heptachlorostyrenes were identified together with octachlorostyrene. HRGC-ElMS spectra of samples taken from different species and fish oil products show considerable dissimilarities in the peak patterns. In all fish samples except one, (E)-β,2,3,4,5,6-hexachlorostyrene (7) was dominant with concentrations up to 41 ng/g fat followed by octachlorostyrene (11) with concentrations up to 24 ng/g fat. α,2,3,4,5,6-Hexachlorostyrene (2) was found in most fish samples, but in rather low concentrations (0-9.2 ng/g fat), while all other compounds were found in only part of the samples in concentrations up to ca. 12 ng/g fat. In fish oil samples, the ratios of the components were even more divergent with either (E)-β,2,3,4,5,6-hexachlorostyrene (7) or 2,3,4,5,6-pentachlorostyrene (1) or even octachlorostyrene (11) as the main component. Concentrations of (E)-β,2,3,4,5,6-hexachlorostyrene (7) in fish samples correlated with those of octachlorostyrene (11), but in every other respect, no consistent pattern of chlorostyrenes has been found in these samples. Degradation studies indicate that the dominance of (E)-β,2,3,4,5,6-hexachlorostyrene (7) is mainly due to direct input but not to environmental degradation.