Method for integrated analysis of polycyclic aromatic hydrocarbons and organochlorine compounds in fish liver

An analytical method for integrated analysis of organochlorine compounds and polycyclic aromatic hydrocarbons (PAH) in large numbers of fish liver samples has been developed using one single clean-up step. Tissues are homogenized with anhydrous sodium sulphate and Soxhlet extracted with n-hexane-dichloromethane (4:1, v/v) for 24 h. The extracts are cleaned-up and fractionated with an alumina chromatographic column allowing the separation of the extracts in two fractions. One containing most organochlorine compounds, including hexachlorobenzene, DDTs and polychlorobiphenyls, and the other the hexachlorocyclohexane isomers and PAH. These two fractions are subsequently analysed by GC-MS. Tests of repeatability result in relative standard deviations mainly under 20%. Evaluation by the standard addition method shows good linearities and recoveries.