UPLC-MS/MS method for determination of paclobutrazol,forchlorfenuron and prochloraz residues in fruits

A rapid method for determination of paclobutrazol,forchlorfenuron and prochloraz residues in watermelon and waxberry was established using ultra high-performance liquid chromatography coupled to tandem mass spectrometry(UPLC-MS/MS).The sample was extracted with acetonitrile and cleaned by solid phase extraction(SPE) cartridge.The mass spectrometer was operated with electrospray in the positive ion mode(ESI+).The target analytes were quantified by external standard method and matrix-matched standard solution used to compensate for matrix effect.Average recoveries of paclobutrazol,forchlorfenuron and prochloraz in watermelon samples were in the range of 85.4%-99.4%,85.6%-98.7% and 88.8%-100.3% at three spiking levels from 0.05-0.2 mg/kg with relative standard deviations of 2.7%-4.0%,2.5%-3.6% and 2.3%-4.6%.Average recoveries of paclobutrazol,forchlorfenuron and prochloraz in waxberry samples were found in the range of 84.3%-99.3%,84.6%-98.2% and 83.6%-99.2% at three spiking levels from 0.05-0.2 mg/kg with relative standard deviations of 2.4%-4.5%,2.9%-3.7% and 2.2%-3.9%.Limits of detections(LOD) of paclobutrazol,forchlorfenuron and prochloraz in fruits were 0.5,0.5 and 0.5 μg/kg,while limits of quantifications(LOQ) were 1.7,1.7 and 1.7 μg/kg.The method is simple and suitable for the routine and confirmation analysis on fruits.