Abstract: A method was established to determine difenoconazole residues in vegetables by high performance liquid chromatography-mass/mass (HPLC-MS/MS). Difenoconazole residues were extracted from vegetables by acetonitrile and cleaned up by carbon/amino solid phase extraction (GCB/NH2-SPE) cartridge. The chromatographic separation was achieved by HPLC and the determination was performed by tandem mass spectrometry in a multiple reaction-monitoring mode. The external standard method was used for the quantification of difenoconazole. A good linear relationship was established in the difenoconazole concentration range of 1－500 ng/mL. The recovery rates of difenoconazole from different spiked samples were in the range of 79.3%－108.0% with relative standard deviations (RSD) of 2.7%－8.5% and the limit of detection for difenoconazole was 0.001 mg/kg. Therefore, the developed method can be used to qualitatively and quantitatively analyze difenoconazole residues in vegetables with satisfactory sensitivity, accuracy and precision.

Key words: difenoconazole, high performance liquid chromatography-mass/mass (HPLC-MS/MS), vegetables, solid phase extraction (SPE)