同位素稀释质谱法测定人血清中痕量硒

Determination of selenium in serum samples by Isotope Dilution Inductively Coupled Plasma-Mass Spectrometry(ID-ICP-MS)

对巯基棉分离硒的方法进行了改进,建立了一种IMEP-17人血清样品中痕量硒的同位素稀释电感耦合等离子体质谱测量方法。采用微波消解-巯基棉分离对人血清样品进行前处理,通过对巯基棉分离血清中硒的条件优化,结果表明,柱条件为5 mol/L HCl、解脱Se条件为1 mL重蒸HNO3、巯基棉最佳用量为0.14 g时,能够有效分离出人血清样品中的Na、Mg、K、Ca等碱金属和碱土金属,同时硒的回收率最高,达到92%以上。将该前处理方法应用到同位素稀释电感耦合等离体质谱法中,平行取样6次,测量结果的平均值为(0.07747±0.00046)μg/g,在标准值(0.07896±0.0027)μg/g的不确定度范围内。

A method for the determination of selenium in serum samples （ IMEP- 17） by Isotope Dilution- Inductively has been developed. The serum selenium is first digested by International Measurement Evaluation Programme Coupled Plasma-Mass Spectrometry （ID-ICP-MS） microwave treatment and then chemically purified before analysis by using sulphydryl cotton. The optimum conditions were found to be as follows： （1） The sulphydryl cotton column is prewashed with 5 mol/L hydrochloric acid; （2） Se is desorbed by adding 1 mL of concentrated nitric acid and （3） the optimum amount of sulphydryl cotton is 0.14 g. This preconcentration step is required in order to remove matrix-interfering elements, such as Na, Mg, K and Ca. The recovery of selenium is above 92 %. The proposed ID-ICP-MS method has been used to determine Se in reference serum materials and the results of six independent measurements （average value is （0. 07747 ± 0. 00046） μg/g） showed good agreement with the certified value（（0.07896 ± 0.0027）μg/R）.