Determination of 19 pesticide residues in cucumber by QuEChERs combined with dilution standard addition calibration method

External calibration based on the standard curve was usually adopted in pesticides multi-residues analysis in complex sample matrices. Solvent calibration was merely suitable for the calibration of sample solutions with small matrix effects. Although matrix matched calibration could compensate for matrix effects， while it could not compensate for process losses. Meanwhile, although standard addition methods and procedural standard calibration methods can compensate for process losses, more samples and/or matrix blanks, more sample preparation time and cost are required. To solve this problem, a dilution standard addition calibration method was established with QuEChERS method and gas chromatography tandem mass spectrometry for the determination of 19 common pesticide residues in cucumber. The results showed that the recovery rates were 85.7%-105.9% with the relative standard deviations （RSDs）of 0.8%-8.5%，and the average measurement uncertainty of 13.6%. Several related parameters such as matrix effect，accuracy，precision，uncertainty and applicability were investigated to provide support basis for the rapid and accurate analysis of the pesticide multi-residue analysis. © 2022, Youke Publishing Co.,Ltd. All rights reserved.