Rapid Determination of Organonitrogen, Organophosphorus and Carbamate Pesticides in Tea by Ultrahigh-Performance Liquid Chromatography–Tandem Mass Spectrometry (UPLC-MS/MS)

A rapid and effective multiresidue method has been developed for the determination of 18 pesticide residues (selected from organonitrogen, organophosphorus, and carbamate pesticides) in tea by ultrahigh-performance liquid chromatography–tandem mass spectrometry. Tea samples were extracted with acetonitrile and purified by a novel multilayer solid-phase extraction cartridge—Cleanet TPT. Evaluation of the influence of the mobile phase on the ionization efficiency, resolution, and sensitivity was carried out by comparing the acetonitrile–water and methanol–water with different modifiers. The recoveries of all the pesticides varied from 70 to 110 % with a relative standard deviation of less than 15 %, and the determination coefficient for each pesticide was R2 > 0.99. Matrix-matched standard calibration curve was used to reduce errors associated with matrix-induced enhancement or suppression effects. The limit of detection for all targeted pesticides ranged from 0.03 to 1.5 μg/kg. Applicability of this analytical approach was confirmed by successful determination of tea samples from different regions of China.