Rapid And Accurate Determination Of Multipesticide Residues In Vegetables By Gas Chromatography-Triple Quadrupole Mass Spectrometry

Pesticide residues are harzards in vegetables and often finally harm to human health. More and more types of pesticides are widely used at present. How to determinate residues of pesticides in vegetables fast and accurately is a great challenge for food safety monitoring.In this paper, a determination method (called QuEChERS) of multipesticide residues in vegetables with Gas Chromatography-Triple Quadrupole Mass Spectrometry (GC/MS/MS) is established. After homogenized samples were treated by an optimized QuEChERS method with acidifing the extraction and using the most appropriate amount of the extraction, PSA and GCB, most types of added pesticides recoveried between 70% and 110% with the relative standard deviation of less than 15%. This method showed rapid, simple, low cost and effective.Matrix effect is the most important reason affecting the accurate quantification of pesticide residues in vegetables, especially to the organophosphorus pesticides. Experiments showed that the main causes of matrix effects are the active ingredients absorption by inlet tube and column. Using standards pre-diluted with matrix solution can eliminate this impact of matrix effects.Finally, the multipesticide residues in vegetables were accurately determined by choosing optimizied conditions, pesticides ions and multiple reaction monitoring mode (MRM). This method showed great advantage for complex matrix sample like onion garlic vegetables.