Abstract: In this study, a rapid, highly sensitive and selective method was developed for the simultaneous determination of residues of sulfoxaflor, pyrifluquinazon and spirotetramat in fruits (apple, grape, and strawberry) and vegetables (cucumber, onion, Chinese cabbage, spinach, and welsh onion) by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The target compounds were extracted from the samples with acetonitrile and cleaned up with dispersive solid phase extraction using primary secondary amine (PSA) and C18 as solid phase before being separated on a C18 column. Two pairs of precursor product ion transitions for sulfoxaflor, pyrifluquinazon and spirotetramat were measured and evaluated under the positive multiple reaction monitoring (MRM) mode. Matrix effects were tested by comparison of reference standards in pure solvent with matrix-matched standards of each matrix. In order to reduce the systematic error, quantification was performed using matrix-matched standard calibration curves. Satisfactory linearity in the concentration range of 0.2–100, 0.02–10 and 0.1–10 μg/L for sulfoxaflor, pyrifluquinazon and spirotetramat, respectively were obtained with correlation coefficients (r) of higher than 0.999 0. Average recoveries of sulfoxaflor, pyrifluquinazon and spirotetramat added to cucumber, grape, apple and scallion ranged from 79.9% to 103.9%, with relative standard deviations (RSD) from 3.3% to 8.8%. The limits of quantification (LOQs) were 0.334, 0.040 5 and 0.378 μg/kg, and the limits of detection (LODs) were 0.100, 0.012 2 and 0.133 μg/kg for sulfoxaflor, pyrifluquinazon and spirotetramat respectively. The method is quick, easy, effective, sensitive and accurate, and can meet the requirements for the determination of residues of sulfoxaflor, pyrifluquinazon and spirotetramat in fruits and vegetables.

Key words: ultra performance liquid chromatography-tandam mass spectrometry (UPLC-MS/MS), fruits and vegetables, pyrifluquinazon, sulfoxaflor, spirotetramat, residues