GC/MSMS Analysis Method Of More Organophosphorus Pesticide Residues Of Spicy Vegetables

In recent years, to improve the productivity and quality of the crop, much more organophosphate pesticides are used than ever, which can effectively control the insects in agriculture. However, abuse of organophosphate pesticides have drawn people’s increasing attention in consideration of the problems it brings, including pesticides residues on the crop, which are harmful to human health because of the potential teratogenic and oncogenic properties. To prevent the pollution of organophosphate pesticides residues, it is critical to establish a simple, rapid and sensitive method for the determination of pesticide residues. The main work in the paper is as following:1.20 organophosphate pesticides were identified and quantified using gas chromatographytandem triple quadrupole mass spectrometry (namely GC-QqQ-MS/MS). Further optimization on chromatographic and mass spectrometry parameters were investigated, including different kinds of chromatographic column, collision voltage, scanning speed, and gas flow rate. The optimal condition was achieved for 20 organophosphate pesticides on DB-35MS column by GC-QqQ-MS/MS.2. The QuEChERS method was modified by improving the extraction and purification conditions of pretreatment. The improvement of QuEChERS method has resulted in increased sensitivity and clean matrix. In the process of sample pretreatment procedure, the effects of different kinds of extract solvent on extracting effects and different kinds of sorbents on purification performance were investigated. A selective and sensitive gas chromatography tandem mass spectrometry method was established for the determination of pesticides. The method validation showed high accuracy and precision at the linear dynamic range 0.002-0.2 mg/kg. The result showed that the recovery of all pesticides ranged from 70% to 120%, and the relative standard deviations (RSD) less than 20%. This method could meet the actual requirements for the simultaneous determination of pesticide residues in Spicy vegetables.3. Chinese chives from ShanDong market were tested. Seven pesticides (dimethoate, methyl chlorpyrifos, methyl parathion, chlorpyrifos, parathion, isopropyl-methyl and triazophos) were detected and the concentration ranged from 0.002 mg/kg to 0.044 mg/kg. The results showed that the method can be used in practice for the pesticide multi-residue analysis of allium vegetables.