Abstract: An analytical method for the simultaneous determination of 129 pesticides in vegetables and fruits was established based on optimized QuEChERS with gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). The samples were extracted with acetonitrile (containing 1% (v/v) acetic acid), then the extracts were determined by GC-MS/MS in multi-reaction monitoring (MRM) mode after being cleaned up with mixed solid-phase dispersion, and the external standard method was applied to quantify the pesticides. The results showed that all the 129 pesticides had good linearity in certain ranges with the correlation coefficients (r2) higher than 0.98. The average recoveries of the most of 129 pesticides in different matrices were in the range of 66.2%-124.7% at the spiked level of 10 μg/kg, with relative standard deviations (RSDs)of 0.9%-24.4%. The limits of quantification (LOQs) of the method were 0.03-16.7 μg/kg. The results demonstrated that the developed method is simple, rapid, sensitive and high efficient for screening multiple pesticide residues in vegetables and fruits.

Key words: fruits, pesticide residues, QuEChERS, vegetables, gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS)