Objective To develop a method for quick determination of residues of seven water-soluble organophosphorus pesticides (trichlorphon, dichlorvos, methamidophos, acephate, omethoate, azodrin, and dimethoate) in fishery products by gas chromatography.
Methods The samples were extracted with purified water by ultrasonic extraction and the soluble proteins were precipitated by lead acetate, then the filtrate was re-extracted by acetonitrile liquid-liquid extraction and primary secondary amine (PSA) solid sorbent for further cleanup of interferences, and finally the targeted pesticides were determined by gas chromatography with flame photometric detection (GC-FPD).
Results Good linear relationships were obtained for the seven pesticides in the range of 0.040-10.000 mg/kg of the analytes with correlation coefficients of 0.998 8-0.999 6 and detection limits of 0.008-0.015 mg/kg (S/N=3). The recoveries for standard addition fell in the range from 77.0% to 109.5% and the relative standard deviations were between 1.4% and 7.1%.
Conclusion This method has been successfully applied to the determination of organophosphorus pesticide residues in real fishery product samples. The method is proven to be simple, rapid, environmental friendly, and satisfied with high sensitivity.
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