Determination of 13 plant growth regulator residues in fruitsand vegetables using ultra performance liquidchromatography tandem mass spectrometry

To develop a ultra performance liquid chromatography tandem mass spectrometry（UPLC-MS/MS）method for the determination of 13 plant growth regulator residues in fruits and vegetables. The sample wasextracted with methanol–H2O and the chromatographic separation was performed on the Shim-pack XR C18 column（75 mm × 2.0 mm，1.6 μm），using acetonitrile-0.1% acetic acid as the mobile phase by gradient elution. Themethod applied electrospray ionization in positive and negative multiple reaction monitoring mode and quantifiedwith peak area with matrix-matched external standard method. A good linearity of Chlormequat chloride，Paclobutrazol，Uniconazole，thidiazuron，gibberellic acid 2-naphthaleneacetic acid，Forchlorfenuron，2，4-D，Cloprop，4-Chloroph-enoxyacetic acid，2，4，5-Trichlorophenoxyacetic acid，6-Benzylaminopurine and isopropylN-（3-chlorophenyl）carbamate were in the concentration range of 1.0-20 μg/L with a correlation coefficient above0.99. The average recoveries from three different were with the range of 81.2% to 106% at spiked levels of 10，20，50 μg/kg，and the relative standard deviations were between 2.13% to 11.8%（n=6）. The limit of quantification wasin the range of 0.022~16 μg/kg. This method is simple，selectivity and suitable for determination of 13 residues infruits and vegetables.