Determination of 72 Pesticide Residues in Tomato Paste by TSQ QUANTUMN-GC

Abstract

A novel method was developed for the determination of 72 pesticide residues in tomato paste by TSQ QUANTUMN GC(GC-MS/MS) combined with QueChers extraction.Optimal concentrations of standard working solutions,SEM(selected ion monitoring) ion pairs,acquisition time window and collision energy were established for MS/ MS analysis of methamidophos and 71 other pesticides in full scan,daughter ion scan and selected ion scan modes.Over the linear range of 5 to 2000 μg/L,the correlation coefficient for each pesticide was bigger than 0.99.Recoveries from spiked samples at three levels indicated that 95.8% of the tested pesticides exhibited a recovery range of 80% to 120% with relative standard deviation smaller than 15% for 87.5% of them.The limits of detection(RSN= 3) varied over the range of 0.04 to 7.5 μg/kg,and limits of quantification(RSN= 10) ranged from 0.1 to 12.9 μg/kg.This method could provide a sensitive,accurate and reilable approach that meets the requirments for quantitative analysis of low levels of pesticides.