Determination of carbendazim,thiabendazole and metalaxyl residues in wax-apple by ultra performance liquid chromatography-tandem mass spectrometry

A rapid method for determining carbendazim, thiabendazole and metalaxyl residue in wax-apples was developed with ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) detection. The samples were extracted with acetonitrile. The samples were detected by UPLC-MS/MS under positive electrospray ionization and multiple reaction monitoring mode. The matrix-matched external standard calibration curves were used for the quantitative analysis. It was shown that the calibration curves were linear in the range of 0.01-0.5 μg/mL and coefficient of determination R2>0.99.The limits of quantitation were 0.04 mg/kg. The average recoveries of the three pesticides were 75%-107% at spiked levels of 0.04, 0.4 and 2 mg/kg, with relative standard deviations in the range of 2.0%-8.9% (n=5). The sample pretreatment of the method is simple and time-saving. The method is applied for detection of carbendazim, thiabendazole and metalaxyl residues in market wax-apples.