同位素稀释质谱法测定人血清中痕量硒

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5mol/LHCl、解脱Se条件为1mL重蒸HNO₃、巯基棉最佳用量为0.14g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。

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

A method for the determination of selenium in International Measurement valuation Programme serum samples (IMEP-17) by Isotope Dilution Inductively Coupled Plasma-Mass Spectrometry (ID-ICP-MS) has been developed. The serum selenium is first digested by 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 5mol/L hydrochloric acid; (2) Se is desorbed by adding 1mL of concentrated nitric acid and (3) the optimum amount of sulphydryl cotton is 0.14g. 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/g).