Determination of 5 Plant Growth Regulator Residues in Fruits by Solid Phase Extraction and Ultra High Performance Liquid Chromatography-Tandem

KeyWord:solid phase extraction£¨SPE£©  ultra high performance liquid chromatography-tandem mass spectrometry£¨UPLC-MS/MS£©  fruits  plant growth regulators

Abstract:

      A method for the simultaneous determination of 5 plant growth regulator residues,including 6-benzyl adenine£¨6-BA£©£¬thidiazuron£¬forchlorfenuron£¬paclobutrazol and uniconazole in fruits was developed by using ultra high performance liquid chromatography-tandem mass spectrometry£¨UPLC-MS/MS£© with solid phase extraction£¨SPE£©.Samples were extracted with acetonitrile£¬then the extracts were concentrated and cleaned up on a NH2 solid phase extraction cartridge with dichloromethane-methanol£¨92¡Ã8£© as elution solution.Sample preparation was accomplished after concentrated and redissoved.The UPLC-MS/MS method was performed with Waters ACQUITY UPLC BEH C18£¨50 mm¡Á2.1 mm£¬1.7 ¦Ìm£© column using water-methanol as mobile phase by gradient elution£¬at a flow rate of 0.3 mL/min.The target compounds were determined by UPLC-MS/MS under multi reaction monitoring£¨MRM£© mode£¬and then quantitatively analyzed by external standard method using the matrix-matched standard solution.The results showed that there were good linearities for 5 plant growth regulators between peak areas and concentrations in the range of 5-500 ng/mL under the optimal conditions£¬with correlation coefficients£¨r2£© of 0.996 1-0.999 6.The spiked recoveries of 5 plant growth regulators in fruits at three spiked levels of 0.004£¬0.02£¬0.1 mg/kg ranged from 75.6% to 110.5% with relative standard deviations£¨RSDs£© of 1.2%-12.8%.The limits of detection of this method£¨LOD£© were in the range of 0.001-0.002 mg/kg£¬and the limits of quantitation£¨LOQ£© were 0.003-0.006 mg/kg.The established method was simple£¬sensitive£¬accurate and reliable£¬and could meet the requirements of multi pesticide residues analysis in fruits.