Determination of Residues of Endosulfan and Its Metabolite in Aquatic Products by Gas Chromatography

A gas chromatography method was established to analyze residues of α-endosulfan,β-endosulfan and endosulfan sulfate in aquatic products.Samples were extracted with acetonitrile and ethyl acetate(4:1,V/V),frozen-degreased,purified with tandem SPE columns(carbon-florisil followed by neutral alumina),and analyzed by gas chromatography with electron capture detector(GC-ECD) and quantified by an external standard method.Each compound showed a good linear relationship over the concentration range of 0.001–0.2 μg/mL.The recovery rates for shrimp,grass carp,oyster and eel spiked with three different levels of endosulfan at 1,10 μg/kg and 20 μg/kg ranged from 74.1% to 106%,with RSD between 1.22% and 7.79%.The limits of detection(LOD) for α-endosulfan,β-endosulfan and endosulfan sulfate were 0.035,0.06 μg/kg and 0.06 μg/kg,respectively,and the limit of quantitation(LOQ) for all of them was 1.00 μg/kg.The method can be applied in the detection of residues of endosulfan and its metabolites in fish,crustacean and shellfish.