HPLC-ICP-MS联用检测转基因大豆中的硒形态

Determination of Selenium Species in Genetically Modified Soybean by High-Performance Liquid Chromatography with Inductively Coupled Plasma Mass Spectrometry

摘要:

本文研究建立了高效液相色谱-电感耦合等离子体质谱（HPLC-ICP-MS）联用检测转基因大豆中的硒酸盐（SeVI）、亚硒酸盐（SeIV）、硒代蛋氨酸（selenomethionine，SeMet）、硒代胱氨酸（selenocystine，SeCys2）和硒代乙硫氨酸（selenoethionine，SeEt）的方法。探讨了色谱柱、流动相及其酸度对分离效果的影响，使用10 mmol/L的柠檬酸溶液（pH值4.5）作流动相，Hamilton PRP X-100色谱柱分离，碰撞反应池技术消除40Ar40Ar+和40Ar2H2+等多原子离子干扰，ICP-MS检测82Se同位素，在21 min内可完全分离检测5种硒形态。探讨了不同提取方法的提取效果，优化了提取条件，采用蛋白酶提取，针对美国进口的转基因大豆样品进行加标回收实验，结果表明采用蛋白酶提取，SeIV和SeVI的回收率在100%左右，SeMet的回收率在92.6%~109.3%之间，SeCys2和SeEt的回收率为81.2%~95.9%。该方法可完全满足转基因大豆中的硒形态定量分析鉴定。

Abstract:

An analytical method to detect selenium species such as selenate [Se(IV)], selenite [Se(VI)], selenomethionine (SeMet), selenocystine (SeCys2), and selenoethionine (SeEt) in genetically modified soybean was established using high-performance liquid chromatography coupled with inductively coupled plasma mass spectrometry (HPLC-ICP-MS). The effects of the chromatographic column, mobile phase, and acidity on separation were evaluated. Hamilton PRP X-100 reversed phase anion exchange column with 10 mmol/L citric acid solution as the mobile phase was used for separation. Collision cell technology was adopted to eliminate the interference of polyatomic ions such as 40Ar40Ar+ and 40Ar2H2+. Isotope 82Se was detected by ICP-MS. The five species were completely separated within 21 min. The extraction procedure was discussed and optimized. A spiked recovery experiment was carried out with proteinase extration, using genetically modified soybean imported from the USA. The result showed that the recoveries were around 100% for Se(IV) and Se(VI), was in the range 92.6%–109.3% for SeMet, and they were in the range 81.2%–95.9% for SeCys2 and SeEt. This method can be used for the quantitative determination of selenium species in genetically modified soybeans.