QuEChERS-超高效液相色谱-串联质谱法快速测定3种叶菜中矮壮素和丙环唑残留

建立了菜心、芥蓝和小白菜中矮壮素和丙环唑残留的分析方法.以QuEChERS法进行样品前处理,采用含1％ HAc的乙腈溶液提取,无水MgSO4、C18及PSA吸附剂净化,超高效液相色谱-串联质谱(UPLC-MS/MS)法测定.对提取溶剂、吸附剂和色谱柱的选择进行了研究探讨.结果表明矮壮素在1～1 000 μg/L、丙环唑在1～500 μg/L浓度范围内均有良好的线性关系.矮壮素和丙环唑的检出限分别为0.1 μg/kg和0.01 μg/kg;在0.010、0.10和0.50 mg/kg 3个添加浓度水平下,菜心、芥蓝和小白菜中矮壮素和丙环唑回收率为75.0％～96.2％;相对标准偏差为0.9％～8.3％;方法定量限为最低添加浓度0.010 mg/kg.该方法快速、简便、准确,满足叶菜中矮壮素和丙环唑残留分析的要求.

Fast Determination of Chlormequat and Propiconazole Residues in Three Leafy Vegetables by QuEChERS-Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

An analytical method was developed for the determination of chlormequat and propiconazole residues in three leafy vegetables including flowering Chinese cabbage,Chinese kale and pak-choi.Target compounds were extracted by acetonitrile containing 1％ acetic acid and cleaned up by magnesium sulfate anhydrous,C18 and PSA adsorbents,then detected with ultra performance liquid chromatography-tandem mass spectrometry.The optimization of extraction solvent,adsorbent and chromatographic column was studied.The linear ranges of chlormequat and propiconazole were 1-1 000μg/L and 1-500 μg/L,respectively with good linear relationship.Limit of detection of chlormequat was 0.1μg/kg while 0.01μg/kg for propiconazole.Recoveries at three spiked levels of 0.010,0.10 and 0.50 mg/kg were ranged from 75.0 ％ to 96.2 ％ with relative standard deviations from 0.9 ％ to 8.3 ％.Limit of quantification of both chlormequat and propiconazole was 0.010 mg/kg.The method is quick,easy and accurate which can meet the requirements for the determination of chlormequat and propiconazole residues in leafy vegetables.