Multiresidue Pesticide Analysis in Tea Using GC-MS/MS to Determine 12 Pesticide Residues (GB 2763-2021)

Pesticides are widely used on tea plants, and pesticide residues are of significant concern to consumers. The National Food Safety Standard Maximum Residue Limits for Pesticides in Food (GB 2763-2021) was recently amended. However, detection methods for pesticides newly added to the list of residues in beverages have not yet been established. For that reason, this study developed a solid-phase extraction (SPE) and gas chromatography-tandem mass spectrometry (GC-MS/MS) method for determining the residues of 12 pesticides, including four newly added, in black and green tea. Sample preparation processes (sample extraction, SPE clean-up, elution solvent, and elution volume) were optimized to monitor these residues reliably. Multiple reaction monitoring (MRM) was used for GC-MS/MS electron impact (EI) mode determination. Finally, satisfactory recoveries (70.7-113.0% for green tea and 72.0-99.1% for black tea) were achieved at three concentrations (10 mu g/kg, 20 mu g/kg, and 100 mu g/kg). The LOQs were 0.04-8.69 mu g/kg, and the LODs were 0.01-3.14 mu g/kg. This study provides a reliable and sensitive workflow for determining 12 pesticide residues in tea, filling a gap in the newly revised National Standards.