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Updated: May 25, 2026
Determination of 45 Pesticides in Avocado Varieties by the QuEChERS Method and Gas Chromatography-Tandem Mass Spectrometry
Published on: December 8, 2023
Determination of multi-class pesticide residues in cucumbers using modified QuEChERS procedure coupled with
Shukun Zhou1, Xiaozhuo Wang1, Ying Kan1
1Division of Chemical Metrology and Analytical Science, National Institute of Metrology, Beijing 100029, China; Key Laboratory of Chemical Metrology and Applications on Nutrition and Health, State Administration for Market Regulation, Beijing 100029, China.
Abstract:
This study presents a metrologically reliable method for the simultaneous determination of 24 multi-class pesticide residues in cucumbers. The method couples a modified QuEChERS procedure with independent gas and liquid chromatography-isotope dilution tandem mass spectrometry (GC-IDMS/MS and LC-IDMS/MS). This dual-platform isotope dilution strategy was systematically optimized to correct for biases arising from extraction inefficiency and matrix-induced ion suppression/enhancement. The developed method had excellent linearity (r2 > 0.999), accuracy (recoveries of 92.2-108.5% for GC-IDMS/MS and 90.4-108.9% for LC-IDMS/MS), precision (RSDs ≤8.6%) and LOQs below regulatory limits. The two independent IDMS methods showed good quantitative agreement, enabling successful cross-validation. It was employed in the value assignment of certified matrix reference materials (GBW (E) 100925-100927) with low relative expanded uncertainties (3-10%, k = 2) and served as the reference method for seven proficiency testing programs. Furthermore, analysis of 60 commercial samples revealed a 40% exceedance rate of MRLs, indicating major food safety concerns.
