Abstract: A method for the determination of nine pesticides including benzoylureas (diflubenzuron, chlorobenzuron, triflumuron, teflubenzuron, flufenoxuron, chlorfluazuron, hexaflumuron) and bishydrazides (methoxyfenozide, tebufenozide) in vegetables was developed by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) with matrix solid phase dispersion. The sample was graphitized with neutral alumina as dispersant and carbon black as purifying, and eluted with ethyl acetate. The separation was achieved by UPLC, and then the identification and quantification were performed using MS/MS with multiple-reaction monitoring and electrospray ionization in positive or negative mode. The following results were obtained: The calibration curves showed good linearity in the ranges of 1~100 μg/L with R2≥0.99; The recoveries were 78.5%~112.8% at four spiked levels of 1, 5, 10, 100 μg/kg, and the relative standard deviations were 2.3%~10.2%; The limits of determination were 0.5~1.0 μg/kg. The method has the advantages of easy to operate, fast to perform, lower limits of quantification, consuming less sample and organic solvents. It can meet the demands of practical use for the rapid and simultaneous determination of benzoylureas and bishydrazides in vegetables.

Key words: benzoylurea pesticides, bishydrazides pesticides, ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), vegetables , matrix solid-phase dispersion