Rapid Screening of Pesticide and Metabolites Residues in Green Tea by Sin-QuEChERS with Ultra Performance Liquid Chromatography-High Resolution Mass Spectrometry

A method for rapid and non-targeted screening of pesticide residues in green tea by Sin-QuEChERS combined with ultra performance liquid chromatography-Q. Exactive Orbitrap mass spectrometry wasdeveloped. The method was optimized using 38 pesticides and metabolites as quality control compounds. The samples were extracted with acetonitrile contained 0.1% formic acid, salted out, shaken, centrifuged, and single-step purified by a Sin-QuEChERS Nano purification column. The separation of sample was performed on a Thermo Accucore aQ (2.1 mm x 150 mm, 2. 6 mu m) column. Methanol and 0.1% formic acid water solution (containing 5 mmol/L ammonium formate) were used as the mobile phase for gradient elution. The analysis was performed in Full MS/ddMS2 scan mode in positive ion mode. The exact molecular weight deviation of each substance was less than 3.8 x 10(-6). The detection result showed that the 38 pesticides and metabolites had good linear relationships within their respective linear ranges (R>0.99). Except for ethiocarb and phosporine, at the spiked levels of 0.01, 0.02 and 0.05 mg/kg, the average recovery of each substance was 68% - 115%, of which the RSDs were 0.4% - 18.9%, and the limits of quantification (LOQs) were 0.005-0.020 mg/ kg. This method was applied to non.target quickly screen residual pesticides in green tea samples and quantify the residual levels, and 10 pesticide residues were detected. The method was simple, fast, efficient and accurate, and could be used for the rapid screening of multi.pesticide residues and metabolites in green tea.