LAUSR

BACKGROUND Flonicamid and dinotefuran are widely applied to control pests and diseases in various economic crops arousing much public concerns about the potential risk to human health. In this study, the multi-determination and residual behavior of flonicamid-dinotefuran mixture on peach trees were investigated. The chronic risk of long-term dietary intake for Chinese consumers was evaluated. RESULTS An optimized QuEChERS method combined with ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis for simultaneous determination of flonicamid, dinotefuran and its metabolites was established to analyze the residual dissipation and terminal residues in peach matrices. The results demonstrated that (1) a satisfactory linearity relationship with the detector response and the correlation coefficient R2 >0.999, the average recoveries of these four analytes ranged from 94% to 108%, the relative standard deviation was between 1.0% and 8.8%, and the limit of the quantitation was 0.02 mg kg-1 ; (2) the dissipation behaviors of flonicamid and dinotefuran followed with the first-order dynamic kinetics model, and the half-lives were 6.9-12.4 days and 8.1-15.1 days, respectively; (3) the recommended harvest interval (PHI) was 21 days, the RQ values of flonicamid and dinotefuran were 16.6% and 20.7%, respectively, which were significantly less than 100%. CONCLUSION The established analytical method met the detection requirement in terms of sensitivity, accuracy, and precision. Additionally, the results indicated that the potential dietary intake risk of the flonicamid-dinotefuran mixture on peach trees was negligible. This work can be utilized in the safe and responsible use of flonicamid-dinotefuran mixture and provide guidance for establishing its MRL in China. This article is protected by copyright. All rights reserved.