Simultaneous Determination of 28 Pesticides and Their Metabolites in Edible Fungi by QuEChERS-UPLC-MS/MS

Edible fungi, with unique flavors and rich nutritional value, are a vital component of residents’ dietary structure; pesticide residues directly impact food safety and the sound development of the industry. Currently, systematic detection methods are lacking for pesticides including 2,3,6-trichlorobenzoic acid, hymexazol, and fluoxastrobin, as well as their metabolites (e.g., acetamiprid-N-desmethyl, endosulfan sulfate, acequinocyl-hydroxy) in edible fungi substrates, and valid standards are unavailable for 21 of these target compounds. This study used QuEChERS pretreatment combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to establish a simultaneous qualitative and quantitative analysis method for 28 pesticides and their metabolites in edible fungi. It focused on optimizing mass spectrometric parameters, including quantitative/qualitative ion pairs and collision energies. Additionally, it systematically investigated key influencing factors (such as organic mobile phase composition and ion source spray needle position) for low-response analytes and optimized the corresponding detection conditions. The results demonstrated that the optimal detection performance, in terms of sensitivity and response stability for all target analytes, was achieved using methanol as the organic mobile phase, setting the ion source spray needle position to +2, and maintaining the desolvation line temperature at 200 ℃. Methodological validation showed that the detection limits of the 28 target compounds ranged from 0.6 to 10.0 μg/kg, the quantification limits ranged from 2.0 to 30.0 μg/kg, the average recoveries were 71.7%-110.4%, and the relative standard deviations (RSDs) were 1.0%-13.0%. The developed method exhibited satisfactory sensitivity, accuracy, and precision, fully meeting the technical requirements for pesticide residue analysis. The method was applied to analyze 39 batches of edible fungi samples, including Agaricus bisporus and Agaricus subrufescens. Residues of three pesticides and their metabolites were detected, further verifying the practicality and reliability of the proposed method. This study provides strong technical support for quality and safety risk monitoring, routine supervision, and source pollution prevention and control of edible fungi.