Abstract: A multi-residue method for the simultaneous determination of 86 pesticide residues in jasmine tea was developed based on optimized quick, easy, cheap, effective, rugged, and safe (QuEChERS) with an improved cleanup procedure using optimized sorbent mixture by gas chromatography-tandem mass spectrometry (GC-MS/MS). Samples were extracted with acetonitrile, and the extracts were cleaned up by liquid-liquid extraction with saturated sodium chloride aqueous solution. Then, the organic phase was transferred into a cylinder filled with a hybrid adsorbent and an organic membrane filter for cleanup and filtration and determinated by GC-MS/MS with an external standard method. The linear range of the developed method was from 5 to 400 μg/kg with correlation coefficients (r2) of more than 0.98. The limits of quantification (LOQs) for the tested pesticides were determinated to be in the range between 0.1 and 8.0 μg/kg. The recoveries of 91.8% of the 86 pesticides at the spiked levels of 80 μg/kg ranged from 70.1% to 116.0%, with relative standard deviations (RSDs) between 1.9% and 11.4% for all the pesticides.

Key words: gas chromatography-tandem mass spectrometry, QuEChERS, jasmine tea, multi-pesticide residues