Abstract: A method for rapid determination of 11 kinds of pesticide residues in tea samples by matrix solid-phase disperse extraction and high performance liquid chromatography and tandem mass spectrometry was proposed. The pesticide residues in tea sample were firstly extracted by a mixture of V(acetonitrile):V(acetic acid)=99:1, and the extract was solid-phase disperse purified by PSA and then separated on a Waters Xterra MS C₁₈ column with a gradient system of a mixture of methanol and water with ammonium formate. Multi-reaction monitoring (MRM) was employed for quantitative determination. Eleven pesticide residues could be detected within 20 min. The linear range of 11 pesticide residue was 0-500 ng·mL ^-1 and the limits of detection were between 0.1-1.7 μg·kg^-1. The correlation rate was more than 0.9995. The average recoveries (spiked at the levels of 10-400 μg·kg^-1) ranged from 62.4% to 114.8% with relative standard deviation between 3.28% and 19.34%. After extraction and purification, 11 pesticide residues in 5 samples of different kinds of tea with significant variation in content were analyzed. And the residue content of 11 pesticides in green tea sample was 1.7-339.4 μg·kg^-1. Recoveries in this sample were ranged from 86.1% to 104.1% with relative standard deviations less than 20%. This method is accurate, sensitive, simple, rapid,safe and suitable for identification and quantification of multiple pesticide residues in tea.

Key words: tea, matrix solid-phase disperse extraction, HPLC-MS-MS, pesticide residues