超高效液相色谱-电喷雾串联质谱法同时测定大豆中107种除草剂残留

Simultaneous Determination of 107 Herbicides in Soybean by Ultra Performance Liquid Chromatography Tandem Mass Spectrometry

采用超高效液相色谱-电喷雾串联四极杆质谱仪(UPLC-ESI-MS-MS),在多反应监测(MRM)模式下建立了测定大豆中107种除草剂残留的定性定量分析方法。方法中的除草剂,覆盖了日本"肯定列表"中规定的大部分除草剂。样品分别用乙腈和V(乙腈)∶V(50mmol/LHCl)=7∶3混合液各提取一次,合并提取液,并与N-丙基乙二胺(PSA)混合去除色素,然后通过冷冻离心去除脂肪,再经过500mgC18小柱进一步净化,得到样品溶液。使用ACQuityUPLCTMBEHC18反相柱,流动相为0.2%甲酸溶液和乙腈,在梯度条件下分析;目标分析物使用超高效液相色谱-电喷雾串联质谱进行测定;以保留时间和离子对(母离子和一个碎片离子)信息比较进行定性和定量。该法的定量限为0.1～50μg/kg。添加水平在0.05～2μg/kg范围内,多数除草剂的加标回收率为58%～130%,相对标准偏差为4.3%～23%。本方法简便、有效、灵敏。适合大豆中残留的多种除草剂筛查检测的需要。

A novel method has been developed for the determination of 107 herbicides in soybean by ultra performance liquid chromatography combined with tandem mass spectrometry （UPLC-MS-MS）, which cover most of herbicides in Japanese Positive List System. The sample was extracted twice respectively by acetonitrile and acetonitrile： 50 mmol/L HCl （7：3, V/V）. The soybean extract was mixed with PSA （primary secondary amine） to remove pigment and fat can be removed by freeze-centrifuging. C18 SPE column was used for further clean-up. The analysis was performed on an ACQuity UPLC^TM BEH C18 column （ 1.7μm, 50mm×1mm i. d. ） utilizing a gradient elution profile and a mobile phase consisting of 0.2% formic acid in water and acetonitrile. The analytes were detected using an electro spray ionization tandem mass spectrometry with multiple reaction monitoring （MRM）. Quantification of the herbicides was based on the peak area of the parent ion and a fragment ion. LOD of different herbicides ranged over 0.1-5 μg/kg and recoveries at 0.05-2μg/kg ranged from 58% to 130%. RSD % was 4.3%-22.7%.