Abstract: Objective To establish a QuEChERS（quick,easy,cheap,effective,rugged,safe） method combined with ultra performance liquid chromatography tandem mass spectrometry（UPLC-MS/MS） for detecting residues of 31 benzimidazole and triazole fungicides in soybean powder. Methods The soybean powder samples were extracted using acetonitrile,the supernatant was purified using octadecyl bonded silica gel（C₁₈） and anhydrous magnesium sulfate,and then blow dry with nitrogen.The samples were separated using Kinetex@F5 100A（3.0×100 mm,2.6 μm） with mobile phases consisting of 0.1% formic acid aqueous solution（phase A） and methanol（phase B）.The electrospray ionization（ESI+） mode was used for ionization,while detection was conducted using multiple reaction monitoring（MRM）. The quantitative detection was performed utilizing the matrix matching method. Results Totally 31 fungicides exhibit a good linear relationship（r>0.999） within the mass concentration range of 0.1-100 μg/L. The limits of detection of the fungicides were 0.01-1.03 μg/kg,the limits of quantitation were 0.01-3.44 μg/kg. The average recovery rate of spiked samples at three different concentrations was 71.3%-118.7%,and the relative standard deviations were 0.4%-9.9%. Conclusion The method is uncomplicated and suitable for rapidly detecting 31 triazole and benzimidazole fungicides in soybean powder samples.

Key words: Ultra performance liquid chromatography tandem mass spectrometry, Benzimidazole fungicides, Triazole fungicides, Soybean powder, QuEChERS