Abstract: A method for the determination of trichlorfon in aquatic products was established based on capillary gas chromatography.Trichlorfon was decomposed into chloral at high temperature inlet.Test samples were extracted with acetonitrile,and the extracts were defatted with petroleum ether and then purified with liquid-liquid extraction.After water removal and concentration,the purified extracts were dissolved into 1 ml acetone solution.The 1 ml acetone solution was added into pear-shaped flask and then determined by using gas chromatography with electron capture detector via external standard method.The recoreries of standard addition are 84.6% to 91.9%,the relative standard deviations are between 3.44% and 13.0%,and the limit of detection is 0.5 μg/kg.

Key words: capillary gas chromatograph, aquatic products, trichlorfon