液相色谱-串联质谱测定豆芽中4种植物生长调节剂

豆芽中植物生长调节剂的滥用是影响其食用安全的主要因素。本文开发了高效液相色谱-串联质谱方法测定豆芽中3-吲哚乙酸、4-氯苯氧乙酸、6-苄基腺嘌呤、赤霉素，质谱检测采用多反应监测模式，采用外标法定量。样品经超声辅助提取后，加入NaCl盐析，有机相经分散固相萃取净化后，进液相色谱-串联质谱检测。4种植物生长调节剂的检出限为5 μg/kg，定量限（limit of quantitation，LOQ）为10 μg/kg。以黄豆芽和绿豆芽为基质，分别做LOQ、2 LOQ和10 LOQ三个水平的添加试验，每个水平6个重复，方法的回收率范围为65.1%~109.8%，相对标准偏差（RSD）范围为1.49%~10.08%。为降低样品测定时假阳性问题，做多反应监测的同时做目标离子的增强子离子扫描。本方法可用于市售的豆芽样品中3-吲哚乙酸、4-氯苯氧乙酸、6-苄基腺嘌呤、赤霉素的监测，为保障消费安全提供技术支撑。
The abuse of plant growth regulator (s) in bean sprouts is a major factor that affects the safety of bean sprouts for consumption. In this study, a high performance liquid chromatography-tandem mass spectrometry (HPLC-MS) method was developed for the determination of 3-indoleacetic acid, 4-chlorphenoxyacetic acid, 6-benzyl adenine and gibberellin in bean sprouts, in which multiple-reaction monitoring mode was employed for simultaneous detection of target analytes and external standards were used for quantification. Test samples were obtained for HPLC-MS analysis, through ultrasonic-assisted extraction, NaCl-induced salting-out, and purification by dispersive solid-phase extraction (to yield organic phase). The detection limit of the 4 plant growth regulators was 5 μg/kg, and the limit of quantitation (LOQ) was 10 μg/kg. The recovery was in range of 65.1%~109.8% and the relative standard deviation (RSD) was in range of 1.49%~10.08% for soybean sprouts and mung bean sprouts when the spiking experiments were performed at the levels of LOQ, 2 LOQ and 10 LOQ with six replicates at each level. The recovery was. Enhanced product ion scan was performed along with the multiple-reaction monitoring in order to reduce false positive results during analysis. This method can be used to monitor the contents of 3-indole acetic acid, 4-chlorphenoxyacetic acid, 6-benzyl adenine and gibberellin in the commercial bean sprouts, and provides technical support for ensuring consumer safety.