Low-Temperature Cleanup Followed by Dispersive Solid-Phase Extraction for Determination of Nine Polar Plant Growth Regulators in Herbal Matrices Using Liquid Chromatography–Tandem Mass Spectrometry

Abstract

Polar plant growth regulators, used alone or doped in fertilizers, are most effective and widely utilized plant growth regulators (PGRs) in agriculture, which play important roles in mediating the yield and quality of crops and foodstuffs. The application scope has been extended to herbal medicines in the past 2 decades and relevant study is inadequate. The aim of this study is to establish a QuPPe-based extraction method containing low-temperature and d-SPE cleanup procedure followed by the detection on a selective multiresidue ultrahigh-performance liquid chromatography − triple quadrupole tandem mass spectrometry (UHPLC–QqQ–MS/MS) in three herbal matrices. This simple, accurate, versatile and robust method was verified according to the validation criteria of the SANTE/12682/2019 guideline document. The analytical range was from 2.5 to 200 μg/L, and the average recoveries were in the range of 64.6−117.8% (n = 6). The optimized method was applied to 135 herbal medicines thereof. Result showed that the detection frequency of chlormequat was the highest in the investigated PGRs, with the positive rate of 15.6%. Improvement of the detection method for polar PGRs will enrich the coverage of PGRs, which is conducive to safeguard public health and ensure drug safety.