Gas Chromatography and Tandem Mass Spectrum
The pesticide residue in vegetables is a key problem of food safety and which is closely related to people’s health. Currently, more and more kinds of pesticides are used in vegetable production. Quick and accurate determination methods of pesticide residue in vegetables are the big challenge which the food inspection agency is facing now.
Based on the detecting data and apparatus in laboratories, scientists establish a new method to determine 39 kinds of different pesticide residue in vegetables at the same time by using gas chromatography and tandem mass spectrum. This method is quick, easy and clean.
The experiment result shows that after the vegetable samples are homogenate processed, extracted by QuEChERS, by acidizing and increasing the extracting solution and purifying N-Propylethylenediamine and graphitized carbon black, the fortified recovery of most kinds of pesticides are between 70% to 110%. The advantages of this method include quick, low cost and effective.
Matrix effect is the key reason for accurate determination of pesticide residue in vegetables, and matrix effect of organophosphorus pesticide is especially obvious.
Through optimizing analysis conditions, laboratory workers are able to choose suitable qualitative and quantitative analytical ion pair of all kinds of pesticides. Finally, they adopt multiple reaction monitoring (MRM) to perform accurate determination of pesticide residue in the samples.