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(T/EH106) Extraction and separation of PCBs and fat in fish samples using SFE with solid-phase trapping. Nilsson, Tobias1, Björklund, Erland1, 1 ABSTRACT- Polychlorinated biphenyls (PCBs) are environmental contaminants with a worldwide distribution. Due to their lipophilicity and persistency they accumulate in the fat compartment of living organisms, which is especially pronounced in the aquatic food chain. Consequently, fishes may contain relatively high concentrations of PCBs, which could posses a threat to humans consuming fish. The amount PCBs present in fishes are often normalized to the amount lipids present in the body since lipids are considered the primary depository for PCBs in aquatic organisms. It is therefore of importance to determine not only the total body burden of PCBs but also the fat present in the fish. This will allow for comparisons of PCB concentrations in various organisms independent of their lipid content. The normal procedure involves Soxhlet extraction followed by various clean-up steps prior to GC analysis. Unfortunately Soxhlet methods are relatively time consuming and requires large amounts of solvents. Alternative techniques such as supercritical fluid extraction (SFE) have therefore started to replace Soxhlet. A model sample consisting of pure triglycerides, with the addition of 10% phospholipids, was fortified with trace amounts of PCBs. All components were quantitatively extracted and collected on a long solid phase trap packed with Florisil. Following the extraction step, the solid phase trap was utilized as a chromatographic column for separation of the trapped compounds. The separation of analytes involved the elution of PCBs and lipids in the mentioned order. Finally the developed method was verified using a well-characterized fishmeal containing PCBs that had been incorporated into the matrix in a natural way via the food chain. Key words: SFE, PCBs, Fat, Fish |
