Gas Chromatography and Tandem Mass Spectrum

Pesticide residue in vegetables is a key problem of food safety and 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 that 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 residues 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 is between 70% to 110%. The advantages of this method include quick, low cost, and effectiveness.

The matrix effect is the key reason for the accurate determination of pesticide residue in vegetables, and the matrix effect of organophosphorus pesticide is especially obvious.

Through optimizing analysis conditions, laboratory workers are able to choose suitable qualitative and quantitative analytical ion pairs of all kinds of pesticides. Finally, they adopt multiple reaction monitoring (MRM) to perform accurate determination of pesticide residue in the samples.