Determination of 20 Kinds of Pesticide Residues in Rice by Gas Chromatography-Tandem Mass Spectrometry

KeyWord:rice  pesticide residues  gas chromatography-tandem mass spectrometry£¨GC-MS/MS£©  QuEChERS  solid phase extraction£¨SPE£©

Abstract:

      Two analytical methods for the simultaneous determination of 20 pesticide residues in rice were proposed.The rice samples were initially extracted with acetonitrile£¨MeCN£©£¬ then cleaned up by C18 SPE column£¨method 1£© and QuEChERS method£¨method 2£©£¬respectively. The extract was analyzed by GC-MS/MS under selective reaction monitoring£¨SRM£© mode£¬in which the pesticides were identified by retention time£¬selected ions and their relative abundances£¬and quantified by the external standard method.The results indicated that the linear ranges of pesticides were between 0.01¦Ìg/mL and 0.2¦Ìg/mL£¬with correlation coefficients all above 0.99.At three spiked concentration levels£¨ 0.01£¬0.05,0.20mg/kg£©£¬the average recoveries of 20 pesticides in rice purified by method 1 ranged from 63.3% to 96.0%£¬with relative standard deviations£¨RSDs£© of 1.9%-13.9%.The average recoveries of 20 pesticides in rice purified by method 2 ranged from 67.7% to 121.0%,with RSDs of 1.9%-16.4%.The results showed that there was no obvious difference between two pretreatement methods£¬and this study provided a different pretreatment way for pesticide residue detection.The proposed method was suitable for the simultaneous determination of multiple pesticide residues in rice.