阳离子交换树脂分离-ICP-MS法测定核纯级二氧化钍中的痕量硼

二氧化钍作为钍基熔盐固态堆的主要燃料,进堆前需严格控制中子吸收截面较大元素硼的含量。本工作针对核纯级二氧化钍中的痕量硼,以阳离子交换树脂Dowex 50W×8为分离纯化材料,以电感耦合等离子体质谱法(ICPMS)为测量手段,建立了一种快速有效的分析方法。当二氧化钍称样量为0.3g时,硼的检出限为0.016μg/g,测得某核纯级二氧化钍样品中的硼含量为(0.111±0.007)μg/g,精密度6.2%(n=6),加标0.667μg/g硼的回收率为91.4%(n=6)。该方法可有效将二氧化钍中的钍基体去除,从而实现痕量硼的准确测量。

Determination of Boron at Trace Level in Nuclear Grade Thoria by ICP-MS After Separated by Cation Exchange Resin

In thoria,the main fuel of solid thorium molten salt reactor,the content of boron must be strictly controlled since it has high neutron absorption cross section.In this paper,arapid method of trace boron measurement in nuclear grade thoria was developed by ICP-MS after the separation of thorium by cation exchange resin.When the mass of thoria is 0.3 g,the detection limit of the methodology is found to be 0.016 μg/g,boron in a nuclear grade thoria is found to be (0.111±0.007) μg/g,while the precision and recovery of the methodology are found to be 6.2％(n=6) and 91.4 ％00 (n=6).With this method,the trace boron can be determined accurately after separating thorium in thoria effectively.