Abstract: A high-throughput quantitative method for the determination of 25 pesticides in tea by GC-MS/MS was established by comparing the QuEChERS method with the traditional SPE method. The factors influencing the extraction and purification effect of QuEChERS and SPE were investigated, and the matrix effect of them was analyzed. The linear relationship of 25 pesticides in the concentration range of 33.33~333.3 ng/mL was good, the correlation coefficient was>0.990, the detection limit of the method was 0.04~3.00 μg/kg, the recovery was 74.99%~104.71%, and the corresponding RSD was 0.4%~9.0%; the linear relationship of 25 pesticides in SPE was good in the concentration range of 25.0~300.0 ng/mL, the correlation coefficient was>0.990, the detection limit of the method was 0.004~0.300 μg/kg. The recovery was 62.90%~104.04%, and the corresponding RSD was 0.2%~6.4%. There was no significant difference in sensitivity and precision between the two methods, which met the requirements of pesticide residue analysis. However, the matrix effect of SPE method is smaller than that of QuEChERS method, and the purification is relatively thorough. Compared with SPE method, QuEChERS method is simpler in operation and faster in detection. Both of the two methods can be used for high-throughput quantitative detection of pesticides in tea samples to ensure reliable control of pesticide residues in tea at the MRL level set by the national food safety standard.

Key words: SPE, QuEChERS, tea, GC-MS/MS, pesticide residues