Determination of 19 Pesticide Residues in Tea Using QuEChERS Extraction and High-performance Liquid Chromatography-Electrospray Tandem Mass Spectrometry

KeyWord:tea  multiresidue analysis  QuEChERS  LC-MS/MS

Abstract:

      A multiresidue method was developed for the simutaneous determination of 19 pesticides in tea by LC-MS/MS. The ionisation mode used was positive mode with multiple reaction monitoring£®The one precursor/two product ion transitions were used for each neonicotinoids£® The procedure£¬based on QuEChERS prior to the determination by UPLC-MS/MS£¬was validated based on the SANCO European Guidelines with satisfactory spiked recovery £¨68%¨C105%£© and measurement uncertainty £¨¡Ü20%£©. The results showed that the calibration curves were linear in the range of 1-15 ¦Ìg/L for 18 analytes and 5-75 ¦Ìg/L for difulubenzuron£®The limits of quantitation £¨LOQ£© were 50 ¦Ìg?kg-1 for difulubenzuron and 10 ¦Ìg?kg-1 for the other 18 pesticides. The method was simple£¬rapid and accurate£¬and could meet the requirement of the maximum residue limits £¨MRLs£© for pesticides in tea as recommended by the European Union.