基于超高效液相色谱-高分辨质谱快速筛查绿茶中12种植物生长调节剂的方法研究

建立了超高效液相色谱-高分辨质谱（ultra performance liquid chromatography-high resolution mass spectrometry，UPLC-HRMS）快速筛查绿茶中2，4-滴、对氯苯氧乙酸、吲哚丁酸、氯吡脲和吲哚乙酸等12种植物生长调节剂的方法。采用CAPCELL PKA-C18色谱柱（100 mm×2.1 mm，2 μm），正离子模式下以体积分数为5%的甲醇水溶液（含有5 mmol/L乙酸铵和体积分数为0.1%甲酸）为流动相；负离子模式下以体积分数为5%甲醇水为流动相，梯度洗脱。在全扫描采集模式下，基于化合物的保留时间、准分子离子峰的精确质量数、碎片离子的精确质量数和同位素分布匹配指数，对目标物进行筛查分析。结果表明:12种植物生长调节剂在绿茶中的报告限（RL）为0.01 mg/kg；在0.01、0.1和0.5 mg/kg 3个添加水平下，其回收率在61%~130%之间，相对标准偏差在1.8%~17%之间。该方法简便快捷，可用于绿茶中常用植物生长调节剂的筛查。

Development of a screening method for twelve plant growth regulator residues in green tea by ultra performance liquid chromatography-high resolution mass spectrometry

A screening method was established for the determination of twelve plant growth regulators (PGRs) in green tea using ultra performance liquid chromatography-high resolution mass spectrometry (UPLC-HRMS), including 2,4-dichlorophenoxy acetic (2,4-D), 4-chlorophenoxy-acetic acid (4-CPA), 4-(3-indolyl) -butyric acid (IAA), forchlorfenuron (CPPU) and 4-indoly-3-ylbutyric acid (IBA), etc. The extract was measured directly by UPLC-HRMS with electrospray ionization in both positive and negative modes. The analytes were separated on CAPCELL PKA-C18 column (100 mm×2.1 mm, 2 μm) with gradient elution．In the positive mode, the mobile phase was methanol-water containing 5 mmol/L ammonium acetate and 0.1% formic acid, while, in the negative mode, methanol-water was used as the mobile phase. The confirmation analysis was based on accurate mass measurement of all compounds (scan mode) and their fragment ions, retention times (RTs) and isotopic patterns (target MS/MS mode). The report limits (RLs) of twelve plant growth regulators were validated as 0.01 mg/kg. At 0.01, 0.1 and 0.5 mg/kg spiked levels, the recoveries and the relative standard deviations (RSDs) were 61%-130% and 1.8%-17%, respectively. This method was simple, quick, and can be applied as a screening method for PGRs detection in green tea.