高效液相色谱-电感藕合等离子体质谱联用测定植物性食品中硒的形态

目的建立一种简单、有效的高效液相色谱-电感耦合等离子体质谱联用(HPLC-ICP-MS)分析食品中5种硒形态的方法。方法对植物性食品样品中不同形态硒化合物提取方法及色谱系统分离柱、流动相、洗脱程序进行交联试验。结果以5 mmol/L柠檬酸,水相pH值=4.7,流速为1.0 ml/min,HamiltonPRP-X100阴离子交换色谱柱能有效分离5种硒形态;超声波辅助链酶蛋白酶E提取30 min,硒形态提取率最高;在5μg/L^100μg/L,5种硒形态呈线性关系,相关系数r均为0.999以上,仪器检出限分别为0.53μg/L^0.96μg/L。平均加标回收率为73.73%~110.6%,相对标准偏差为1.01%~9.75%。结论采用该方法,5种硒化合物分离迅速,6 min内分离出4种化合物,22 min内全部分离完成,分离度R值均>1.5,分离效果良好;用于植物性食品中硒形态的检测,用超声波辅助链酶蛋白酶E的提取效率最高,检测到的5种硒化合物总量与总硒的百分比在75%左右,结果令人满意。

Determination of selenium forms in vegetable food by high performance liquid chromatography-inductively coupled plasma mass spectrometry

Objective To establish a simple and effective method for the determination of five selenium forms in food by high performance liquid chromatography-inductively coupled plasma mass spectrometry(HPLC-ICP-MS).Methods The extraction methods of selenium compounds in different forms in vegetable food samples and the cross-linking tests of chromatographic column,mobile phase and elution program were conducted.Results Hamilton PRP-X100 anion exchange chromatography column could effectively separate five forms of selenium with 5 mmol/L citric acid,water phase pH=4.7,flow rate of 1.0 ml/min.The extraction rate of selenium forms was the highest with ultrasonic assisted Streptase protease E extraction for 30 minutes.The five forms of selenium were linearly correlated with each other within 5 g/L-100 g/L,and the correlation coefficients(r)were above 0.999.The detection limits of the instrument were within 0.53μg/L-0.96μg/L.The average recovery of standard addition and the relative standard deviation were within 73.73%-110.6%and 1.01%-9.75%.Conclusion Five selenium compounds were separated quickly by this method.Four selenium compounds were separated in 6 minutes,and the separation was finished in 22 minutes.The R value of separation degree was greater than 1.5,indicating good separation efficiency.The detection of selenium species in vegetable food has the highest extraction efficiency using ultrasound-assisted streptase E.The total amount of the five detected selenium compounds and the percentage of total selenium is about 75%,with satisfactory results.