Rapid Determination of 12 Plant Growth Regulators in Bean Sprouts by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry

A method was proposed for the rapid determination of 12 plant growth regulators in bean sprouts by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The sample (5.00 g) was extracted with 10 mL of a mixture of acetic acid and acetonitrile at volume ratio of 1∶99. After centrifugation, 1.0 mL of the supernatant was purified by QuEChERS. Waters Acquity UPLC^® HSS T3 chromatographic column was used as stationary phase, and the mixtures of acetonitrile and 5 mmol·L^-1 ammonium formate containing 0.1% (φ) formic acid at different volume ratios were used as mobile phase for gradient elution. ESI⁺, ESI^- and the mode of multireaction monitoring (MRM) were adopted in MS/MS, and matrix matching external standard method was used for quantitative analysis. The results showed that linear relationships between values of mass fraction and peak area of 12 plant growth regulators were found in the definite ranges, with detection limits (3S/N) in the range of 0.60-6.0 μg·kg^-1. Test for recovery was made by standard addition method, giving results in the range of 70.0%-110%, and RSDs (n=5) of the determined values less than 10%. This method was used to analyze 32 samples bean sprouts, and the detection rate was 31.25%.