高效液相色谱-电感耦合等离子体质谱法同时测定植物性富硒食品中7种硒元素形态含量

Simultaneously determination of the content of 7 kinds of selenium species in plant-based selenium-enriched food by high performance liquid chromatography-inductively coupled plasma mass spectrometry

中文关键词:  硒元素形态  液相色谱-电感耦合等离子体质谱法  动态反应池  富硒食品

英文关键词:selenium speciation  high performance liquid chromatography-inductively coupled plasma-mass spectrometry  dynamic reaction cell  selenium-enriched food

中文摘要:

      目的 考察微波辅助下酶解法的提取效果, 基于动态反应池(dynamic reaction cell, DRC), 建立高效液相色谱-电感耦合等离子体质谱法(high performance liquid chromatography-inductively coupled plasma mass spectrometry, HPLC-ICP-MS)同时测定植物性富硒食品中7种硒元素(硒酸根、亚硒酸根、硒代胱氨酸、L-硒甲基硒代半胱氨酸、L-硒代蛋氨酸、甲基亚硒酸、硒代乙硫氨酸)形态的含量。方法 样品经微波辅助胰蛋白酶酶解, 高速离心后取上清液过水相滤膜。采用HPLC-ICP-MS仪, 以甲烷为反应气体DRC模式消除质谱干扰, 内标校正, 以外标法进行定量分析。优化色谱和质谱条件, 从酶的种类、酶的用量、萃取温度、萃取时间、加标回收率等方面考察前处理方法对待测物的提取效果。结果 7种目标物在0.5~100.0 μg/L范围内呈良好线性关系, 相关系数(r)均大于等于0.9998, 平均回收率为91.45%~102.75%, 检出限为0.10~0.30 μg/kg, 定量限为0.30~0.90 μg/kg, 日间日内精密度(n=6)分别小于5%和9%。结论 该方法准确、灵敏, 适用于食品中7种硒元素形态的同时检测。

英文摘要:

      Objective To study the extraction effects of microwave-assisted enzymatic hydrolysis, establish a method for determination of 7 kinds of selenium species (selenate, selenite, selenocysteine, L-selenium methyl selenocysteine, L-selenomethionine, methyl selenite acid and selenoethionine) in plant-based selenium-enriched food by high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) based on dynamic reaction cell (DRC). Methods The samples were enzymatically hydrolyzed by microwave-assisted trypsin, and the supernatant was removed from the aqueous phase filter membrane after high-speed centrifugation. MS interference was eliminated by DRC using methane as reaction gas with HPLC-ICP-MS method, and quantitative analysis was achieved by external standard after calibrated by the internal standard. After the conditions of chromatography and mass spectrometry were optimized, the extraction effect of pretreatment method was investigated from the aspects of enzyme type, enzyme dosage, extraction temperature, extraction time and spike recovery. Results The results showed a good linearity from 0.5–100.0 μg/L and the value of the corresponding correlation coefficients r were all larger than 0.9998. The average recoveries were 91.45%–102.75%, the values of limit of detection were 0.10–0.30 μg/kg, and those of limit of quantification were 0.30–0.90 μg/kg, and the intra-day and interday precision values were below 5% and 9%, respectively. Conclusion The results shows that the established method is accurate, sensitive, and is suitable for the analysis of 7 kinds of selenium species in food simultaneously.