Simultaneous determination of 16 pyrethroid residues in tea samples using gas chromatography and ion trap mass spectrometry.

Pyrethroids are widely used in tea production, and pesticide residues in brewed tea are becoming a major issue. Thus, an appropriate control method of pyrethroid residues in tea samples has to be developed and used to reduce the potential health hazard from consumption of pyrethroids. A method is described here for the simultaneous determination of 16 pyrethroid residues in tea samples. The insecticides were extracted using acetone and then underwent cleanup through a florisil column. Analysis was performed by gas chromatography with ion trap mass spectrometry (GC IT-MS) in MS MS mode. Retention time and specific ions were used for identification. Recoveries at spiked levels (0.001-0.2 μg/g) for the 16 pyrethroids ranged from 71.3% to 106.3%, and the coefficient of variation was less than 17% in each case. The limits of detection were from 0.001 to 0.05 μg/g. The proposed method was successfully applied to determine pyrethroid residues in 25 brewed made tea samples. It was found that there were bifenthrin, cyfluthrin, lamda-cyhalothrin, cypermethrin, dicofol, fenpropathrin, fenvalerate, fluvalinate, and tetramethrin residues in different samples with levels ranging from 1.18-3071.29 μg/kg.