Simultaneous Determination of Four Pesticides Residues in Vegetables by Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

KeyWord:ultra performance liquid chromatography-tandem mass spectrometry£¨UPLC-MS/MS£©  solid phase extraction£¨SPE£©  pesticide residue  vegetable

Abstract:

      A method was developed for the determination of four pesticides residues in a variety of vegetables using solid phase extraction£¨SPE£© and ultra performance liquid chromatography-triple quadrupole-mass spectrometry£¨UPLC-MS/MS£©.The purification methods£¨solid phase extraction column,QuEChERS method,elution solvent,elution volume£©,chromatographic conditions£¨mobile phase type,flow rate and column temperature£© and mass spectrometric parameters£¨fragment,delta EMV£© were optimized.The pesticides samples were extracted with acetonitrile,and then cleaned up on a Carbon/NH2£¨or NH2£© SPE column.The eluting solution was evaporated and made up to a definite volumn with methanol,finally analyzed by reversed phase ultra performance liquid chromatography under multiple reaction monitoring£¨MRM£© of positive ion mode with the external standard method.The calibration curves of four pesticides showed good linearities in the range of 5-500 ¦Ìg/L with correlation coefficients not less than 0.999 2.The limits of detection£¨LOD£© were in the range of 0.033-0.167 ¦Ìg/kg and the limits of quantitation£¨LOQ£© were in the range of 0.10-0.50 ¦Ìg/kg for 4 pesticides spiked in vegetable.The recoveries of 4 pesticides in vegetable sample spiked with three concentration levels of 10,50,250 ¦Ìg/kg ranged from 70.9% to 123.4% with RSDs less than 15%.The established method was accurate,sensitive and simple,and was suitable for the simultaneous analysis of various pesticides residues.