Determination of 5 Avermectin Residues in Fruits and Vegetables by Liquid Chromatography-Tandem Mass Spectrometry

KeyWord:liquid chromatography-tandem mass spectrometry£¨LC-MS/MS£©  avermectin residues  fruits  vegetables

Abstract:

      A liquid chromatography-tandem mass spectrometric method was developed for the simultaneous determination of 5 avermectin residues£¨e.g.abamectin,ivermectine,eprinomectin,emamectin benzoate B1a and emamectin benzoate B1b£© in fruits and vegetables.After extracted with acetonitrile,avermectin residues were cleaned up by PSA and C18 dispersive solid phase extraction.Influences of mobile phases,procedure of solvent gradient and temperature of the desolvation gas were investigated.Experimental results revealed that the most signal intense precursor ions£¨£ÛM+ NH4£Ý+£© were observed when desolvation gas temperature of 250 ¡æ was used.The method was evaluated in terms of the limits of detection and quantitation.The linearity of the analytical response within the studied range of 3 orders of magnitude was excellent,with correlation coefficients higher than 0.999.The mean recoveries of all analytes in 5 spiked fruits and vegetables matrix were in the range of 74%-110%,with relative standard deviations of 0.4%-12.1%.The limits of detection for abamectin,ivermectine,eprinomectin,emamectin benzoate B1a and emamectin benzoate B1b were 0.6,0.6,0.3,0.06,0.6 ¦Ìg/kg,respectively.The method was efficient,reliable and sensitive,and could meet the requirements for the determination of 5 avermectin residues in fruits and vegetables.