Abstract:

Six plant growth regulators frequently used in five fruits of apple，grape，peach，navel orange and kiwifruit were determined by UPLC–MS/MS including chlormequat chloride，GA3，forchlorfenuron，paclobutrazol，thidiazuron and 2,4-D. A modified QuEChERS method was used in pretreatment：Extracted with acetonitrile containing 1% acetic acid，cleaned up by the mixture of ODS and MgSO4. The detection was performed with electrospray ionization（ESI）using multiple reaction monitoring mode，and quantified by the external standard method. The result indicated that the calibrationcurves of six plant growth regulators were linear in the range of 1–100 μg · kg-1 with correlation coefficients over 0.999. The recoveries at four spiked concentration levels of 1，20，50，100 μg · kg-1 ranged from 60.77% to 119.43% and RSD were between 0.18% and 32.94%. The limits of detection（LOD）and limits of quantitation（LOQ）were 0.01–0.14 μg · kg-1 and 0.02–0.46 μg · kg-1 for apple，0.01–0.18 μg · kg-1 and 0.03–0.59 μg · kg-1 for grape，0.01–0.08 μg · kg-1 and 0.04–0.28 μg · kg-1 for kiwifruit，0.003–0.11 μg · kg-1 and 0.01–0.38 μg · kg-1 for peach，0.01–0.08 μg · kg-1 and 0.03–0.25 μg · kg-1 for navel orange，respectively.

Key words: fruit, UPLC–MS/MS, plant growth regulator