Determination of 6 Plant Growth Retardants in Fruits and Vegetables by HPLC-MS/MS

KeyWord:Key words£ºhigh liquid chromatography-electrospray ionization tandem mass spectrometry£¨HPLC-ESI-MS/MS£©  plant growth retardants£¨PGRs£©  residues

Abstract:

      A comprehensive analytical method based on high performance liquid chromatography-electrospray ionization tandem mass spectrometry£¨HPLC-ESI MS/MS£© under positive ionization mode was developed for the determination of 6 plant growth retardants£¨PGRs£© residues£¬including choline chloride£¬chlormequat chloride£¬mepiquat chloride£¬ancymidol£¬paclobutrazol and uniconazole in fruits and vegetables.The samples were extracted with methanol by ultrasonic wave assistant extraction£¨UAE£©.The extract was purified and concentrated by solid phase extraction£¨SPE£© with Waters Oasis HLB column£¨3 mL£¬60 mg£©.The separation of the target compound was performed with Thermo Hypersil Gold aQ£¨2ª±1 mm¡Á150 mm£¬3 ¦Ìm£© column by gradient elution.The identification of 6 PGRs was carried out by ESI under the positive ion mode.Effects of mobile phase and additives on ionization were investigated.Effects of the types and amounts of extraction solvents and the types of SPE column were also studied.Under the optimal conditions£¬the calibration curves of 6 PGRs were linear in the range of 1ª±0-200ª±0 ¦Ìg/L with correlation coefficients£¨r£© more than 0ª±99.Recoveries of 6 PGRs at three spiked concentration levels of 2ª±0£¬10ª±0,50ª±0 ¦Ìg/kg ranged from 81% to 104% with relative standard deviations no more than 5ª±0%.The detection limits£¨LOD£© were in the range of 0ª±15-0ª±35 ¦Ìg/kg and the quantitative limits£¨LOQ£© were 0ª±47-1ª±10 ¦Ìg/kg.The established method has the advantages of high sensitivity£¬nice selectivity and low detection limit£¬and was applied in the determination of PGRs in fruits and vegetables with satisfactory results.