Studies on Residue Determination of Organophosphorus Pesticides in Spinach

An efficient gas chromatographic method for the determination of 6 kinds of organophosphorus pesticide residues in spinach had been established, and the pretreatment of specimen was also discussed. The organophosphorus pesticides were extracted from spinach samples with acetone and dichloromethane. The satisfactory results were obtained when the experiment had been carried out with refining for one time and extraction for two times. The extracted residues were separated through the DB-17 capillary column, then qualitatively and quantitatively measured by gas chromatograph with flame photometric detector. Minimum detection limits of this method were between 6.08×10-4~1.66?0-3mg/kg, the recoveries of organophosphorus pesticide residues ranged from 82.52%~92.02%, with an average RSD of 6.31%~17.06%. The results of this test had met the requirement of national method of pesticide residue analysis.