QuEChERS-超高效液相色谱-串联质谱法同时测定蔬菜中6种植物生长调节剂

为提高高沸点极性植物生长调节剂的检验效率,建立同时测定蔬菜中6种羧酸类植物生长调节剂（吲哚-3-乙酸、吲哚-3-丁酸、2,4-D、α-萘乙酸、赤霉酸、4-氯苯氧乙酸）残留量的Qu ECh ERS-超高效液相色谱-串联质谱（UPLC-MS/MS）方法。样品采用含1%乙酸的乙腈提取,无水硫酸镁-氯化钠盐析,无水硫酸镁-石墨化炭黑（GCB）分散固相萃取（d-SPE）净化。液相色谱以BEH C18柱（50 mm×2.1 mm,1.7μm）为分析色谱柱,乙腈和0.01%乙酸水溶液作流动相进行梯度洗脱。质谱分析采用电喷雾负离子电离、多反应监测模式,以基质匹配标准曲线外标法定量。6种植物生长调节剂在各自浓度范围内线性良好（r>0.99）,以黄瓜和番茄为代表性基质进行3个水平加标回收实验,回收率在81.6%¹08%之间,相对标准偏差（RSD）在1.3%⁸.4%之间,方法检出限为0.5⁶μg/kg。该方法操作简便、耗时短、灵敏度和准确性好,可满足蔬菜中植物生长调节剂残留量的快速测定的需要。 

Determination of six plant growth regulators in vegetables by Qu ECh ERS- ultra performance liquid chromatography- tandem mass spectrometry

To improve the detection efficiency of polar plant growth regulators with high boiling point,a new method for the simultaneous determination of 6 carboxyl- contained plant growth regulators( indole-3- acetic acid,indole-3- butyric acid,2,4- D,α- naphthaleneacetic acid,gibberellic acid and 4- chlorophenoxyacetic acid) residues in vegetables was developed by Qu ECh ERS- ultra performance liquid chromatography- tandem mass spectrometry( UPLC-MS/MS). The analytes were extracted with acetonitrile containing 1% acetic acid,and salted out with anhydrous magnesium- sodium chloride. The extracts were cleaned up by dispersive solid phase extraction( d-SPE) using anhydrous magnesium- graphitized carbon black( GCB) as sorbents. Chromatographic analysis was carried out on BEH C18column( 50 mm × 2.1 mm,1.7 μm) using a mobile phase comprised of acetonitrile and water( containing 0.01% acetic acid) in gradient program. The plant growth regulators were analyzed by negative electrosprary ionization( ESI-) tandem mass spectrometry under multiple reaction monitoring( MRM) mode.Quantification was achieved using matrix- matched external standard method.The calibration curves showed good linearity in each concentration range,and the recoveries of the 6 plant growth regulators spiked at three levels in cucumber and tomato were between 81.6% and 108%,with the relative standard deviation( RSD) ranging from1.3% to 8.4%.The limits of detection( LODs) in vegetables were in the range of 0.5 μg / kg and 6 μg / kg.The method is simple,convenient,time- saving,sensitive and accurate,and suitable for the rapid determination of plant growth regulators residues in vegetables.