Distribution of polychlorinated biphenyl residues in several tissues of fish from the North End Lake, Port Elizabeth, South Africa

The concentrations and distribution of 6 PCB indicator congeners (IUPAC nos. 28, 52, 101, 138, 153, and 180) were measured in 236 organ samples of fish (Cyprinus carpio and Oreochromis mossambicus) from the North End Lake in Port Elizabeth, South Africa. Polychlorinated biphenyls (PCBs) were extracted from the fish muscles, gills, gonads and livers using USEPA method 8082, followed by a clean-up using concentrated sulphuric acid and florisil column chromatography. Analysis was achieved by gas chromatography–mass spectrometry (GC/MS) using the internal standard method. The concentrations of total PCBs in the liver, gonads, gills and muscle were 95.69, 57.49, 44.63, 34.14 ng∙g-1 lipid weight (lw) in C. carpio and 119.73, 59.21, 49.78, 34.63 ng∙g-1 (lw) in O. mossambicus, respectively. These values were relatively low compared to those reported in the literature. PCB levels were predictably highest in the lipid-rich livers. Individual congeners were not distributed homogeneously within the investigated organs. PCBs 153 and 138 were present at higher concentrations than other PCB congeners for both species. PCB contaminants in fish act as indicators of pollution in aquatic ecosystems and are a potential threat to human health when consumed.