Method validation, dissipation and risk ranking of multi-pesticides in blueberry

Abstract

Blueberry production and consumption are gradually increasing in China; however, the potential risks of pesticide residues are essentially unknown. In this study, a modified QuEChERS method was used for the analysis of twenty pesticides and their nine metabolites in blueberry by ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) and gas chromatography with tandem mass spectrometry (GC-MS/MS). This method achieved high linearity (R2 > 0.99), accuracy (average recovery, 70–125%), precision (relative standard deviation, RSD ≤12%), and sensitivity (limit of quantification, LOQ, 0.01 mg/kg). The dissipation of most pesticides fitted the first-order model, and the half-lives were in the range of 2.21–35.65 d. The residual levels of the analytes on the first day after application were below maximum residue limits (MRLs) on fruits, and ten pesticides with MRLs in China were categorized as low-risk pesticides according to the risk ranking. This study provides a reference for the rational application of pesticides for blueberry cultivation.