Development and validation of a combined QuEChERS and HPLC-MS/MS method for trace analysis of ten diamide insecticides in agricultural products†

Abstract

Diamide insecticides are being widely registered worldwide, yet most of them lack established maximum residue limits (MRLs) in agricultural products. In this study, we combined a QuEChERS (quick, easy, cheap, efficient, rugged, and safe) extraction method with high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) analysis to simultaneously identify and quantify ten diamide insecticides in seven matrices for the first time. The method was validated in accordance with SANTE/11312/2021 guidelines, including sensitivity, linearity, trueness, and precision. Excellent linearity (R² > 0.99) was obtained for all diamide insecticides within the concentration range of 5–1000 µg kg⁻¹. The limit of detection (LOD) and limit of quantification (LOQ) were 0.01–1 µg kg⁻¹ and 5 µg kg⁻¹, respectively. The recoveries of the ten diamide insecticides at three levels (5, 100, and 1000 µg kg⁻¹) ranged from 76.6% to 108.2% with good intra-day relative standard deviation (RSD_r) (1.0–13.4%) and inter-day relative standard deviation (RSD_R) (2.3–15.7%). The proposed method was applied to analyze 70 real agricultural product samples, and only six samples contained diamide insecticides. The results demonstrated that the method was both convenient and reliable for detecting diamide insecticides in agricultural products. The method was then applied to analyze agricultural product samples collected in a field trial to estimate the MRLs for the next step.