Determination of DCPTA in Mung Bean by Dispersive Solid-Phase Extraction and Ultra-High-Performance Liquid Chromatography–Tandem Mass Spectrometry

A novel procedure was developed for the determination of DCPTA residues in mung bean using dispersive solid-phase extraction (DSPE) couple with ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS). Sample was extracted with a HAc-acetonitrile solution (1:99, V/V) and primarily purified by DSPE with C18, PSA, and GCB as absorbent. In order to detect DCPTA residues from mung bean, retention time, quantitative ions, and qualitative ions were used for screening and confirmation. The effect DSPE conditions of the type and dosage of adsorbents and extraction condition were researched, and then the suitable method was founded. Under the optimized conditions, the detection limit (S/N = 3) and quantitative limit (S/N = 10) of DCPTA were 0.11 μg kg−1 and 0.37 μg kg−1, respectively. The average recoveries ranged from 93.8 to 96.8% at spiking levels of 1.0, 5.0, and 10.0 μg kg−1, with a relative standard deviation (RSD) lower than 6.2% (N = 6). This method is simple, accurate, and sensitive, and is suitable for the rapid screening and confirmatory analysis of plant growth regulator residues in coarse grains.