Determination of Plant Growth Regulators in Vegetable by High Performance Liquid Chromatography-Tandem Mass Spectrometry Coupled with Isotop-coded Derivatization

A method for determination of 6 plant growth regulators by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) coupled with isotope-coded derivatization was developed. d 0 -10-Methyl-acridone-2-sulfonyl piperazine (d 0 -MASPz, light form) and d 3 -10-methyl-acridone-2-sulfonyl piperazine (d 3 -MASPz, heavy form) were prepared as isotope-coded derivatization reagents for carboxyl compound. The carboxylic plant growth regulator standards and real samples were derivatized by d 0 -MASPz and d 3 -MASPz, respectively. The obtained solutions were mixed at a certain ratio, and then injected for HPLC-MS/MS analysis. The light and heavy derivatives were monitored with transitions of [M + H] + → m / z 208.2 and [M + H] + → m / z 211.2, respectively. With heavy derivative as internal standard for corresponding light derivative, the global isotope internal standard quantification for 6 plant growth regulators was achieved. The results indicated that the proposed isotope-coded derivatization method could provide relative quantitative data with adequate linearity in a 10-fold dynamic range ( R = 0.9991). The detection and quantitation limits were 0.19–0.34 μM and 0.53–0.96 μM, respectively. The relative standard deviations were ≤ 3.8%, and the accuracies ranged from 97. 5% to 103.8%.