Multiresidue Determination of Organophosphorus Pesticides in Fruits and Vegetables by Gas Chromatography-Negative Chemical Ionization-Mass Spectrometry

A gas chromatography-negative chemical ionization-mass spectrometry(GC-NCI-MS) method was established to simultaneously determine 9 organophosphorus pesticide residues in fruits and vegetables.Samples were extracted with ethyl acetate and cleaned up on a Florisil column before GC-NCI-MS analysis in a selective ion-monitoring(SIM) mode.The internal standard used was ethion.The presented method was rapid,simple,sensitive and selective.The detection limits of this method for 9 organophosphorus pesticides were in the range of 0.12-1.21 μg/kg.The average recovery rates of 9 organophosphorus pesticides varied from 76.5% to 112% with a relative standard deviation of 1.45%-11.0%.