Abstract:  A novel method was developed for the rapid determination of 22 representative pesticide residues in vegetables and fruits based on accelerated solvent extraction (ASE) coupled with online gel permeation chromatography-gas chromatography-mass spectrometry (GPC-GC-MS). The sample was extracted by accelerated solvent extraction with dichloromethane-acetone (1:1, v/v) and purified with a carbon/NH2 column, evaporated to dryness by nitrogen, then dissolved in cyclohexane-acetone (7:3, v/v), and finally identified and quantified by GPC-GC-MS system in selected ion monitoring (SIM) mode. The results showed that the linearities of the 22 pesticides were good in their linear ranges. The limits of detection (S/N=3) were 0.3~1.8 μg/kg. The limits of quantification (S/N=10) ranged from 1~6 μg/kg. The recoveries for all at three spiked levels in Chinese cabbages and apples ranged from 70.5% to 107.5% with the relative standard deviations (RSDs) of 2.1%~8.7%. The proposed method is accurate, sensitive and highly efficient in the extraction, and can be used for the quick determination of the pesticide multiresidues in vegetables and fruits.

Key words: fruits, gas chromatography-mass spectrometry (GC-MS) , gel permeation chromatography (GPC) , pesticide multiresidues, vegetables, accelerated solvent extraction (ASE)