液相色谱-电感耦合等离子质谱联用法测定大豆中的5种硒形态

Determination of 5 kinds of selenium species in soybean by liquid chromatography-inductively coupled plasma mass spectrometry

中文关键词:  液相色谱法  电感耦合等离子质谱法  大豆  硒形态

英文关键词:liquid chromatography  inductively coupled plasma mass spectrometry  soybean  selenium species

中文摘要:

      目的 建立液相色谱-电感耦合等离子质谱法(liquid chromatography-inductively coupled plasma mass spectrometry, LC-ICP-MS)测定谷物类大豆样品中5种硒形态[硒代胱氨酸(SeCys2)、甲基硒代L-半胱氨酸(MeSeCys)、亚硒酸根(SeⅣ)、硒代蛋氨酸(SeMet)和硒酸根(SeVI)]的分析方法。方法 样品采用超声水解, 加入链酶蛋白酶E提取, 经C18反向色谱柱(4.6 mm×150 mm, 5 μm, 100 ?)分离, 以30 mmol/L磷酸氢二铵、 0.5 mmol/L四丁基溴化铵、2%甲醇为流动相, 流动相的pH用甲酸调节至5.8~6.0, 通过ICP-MS测定5种硒形态。结果 经方法优化后, LC-ICP-MS方法可以在8 min内将5种硒形态完全分离, 且各个硒形态标准曲线的线性关系良好(r2≥0.995), 方法检出限为0.5~1.0 μg/L, 定量限为1.5~3.0 μg/L, 加标回收率为97.34%~100.33%, 相对标准偏差为0.46%~1.2%。结论 本方法具有前处理简单、快捷, 灵敏度高, 分析速度快等优点, 适用于大豆食品中硒的形态分析。

英文摘要:

      Objective To establish a method for determination of 5 different forms of selenium [selenium cystine (SeCys2), methyl selenium generation L-cysteine (MeSeCys), and selenium acid radical (Se Ⅳ), selenomethionine (SeMet) and selenium acid group (SeVI)] in grain soybean samples by liquid chromatography with inductively coupled plasma mass spectrometry (LC-ICP-MS). Methods The samples were hydrolyzed by ultrasound and extracted by adding pronase E, and separated by C18 chromatographic column (4.6 mm×150 mm, 5 μm, 100 ?) using 30 mmol/L diammonium phosphate, 0.5 mmol/L tetrbutyl ammonium bromide, and 2% methanol as mobile phase. The pH of the mobile phase was adjusted to 5.8~6.0 by formic acid, then 5 selenium forms were determined by ICP-MS. Results After the optimization of the method, 5 selenium forms could be separated completely in 8 minutes by LC-ICP-MS, and the linear relationship of the standard curves of selenium forms was good (r2≥0.995). The limits of detection the method were 0.5–1.0 μg/L, the limits of quantitation were 1.5– 3.0 μg/L, the recovery rates were 97.34%–100.33%, and the relative standard deviations were 0.46%–1.2%. Conclusion This method has the advantages of simple, fast pretreatment, high sensitivity and fast analytical speed, and is suitable for speciation analysis of selenium species in soybean food.