同位素稀释质谱法分析铀样品中微量钍  

Analysis of Trace Thorium in Uranium Sample Using Isotope Dilution Mass Spectrometry

作　　者：傅中华[1] 龙开明[1] 刘雪梅[1] 韩军[1] 汤磊[1] 

机构地区：[1]中国工程物理研究院,核物理与化学研究所,四川绵阳621900

出　　处：《物理化学学报》2015年第B05期14-18,共5页Acta Physico-Chimica Sinica

摘　　要：以239Th为稀释剂的同位素稀释质谱法是分析铀材料中微量杂质元素钍的准确分析方法，在该方法分析铀材料中微量杂质元素钍时，需要先将微量钍从铀材料样品中的大量铀和其它微量杂质元素中分离出来．本研究建立了强碱性阴离子交换和磷酸三丁酯（TBP）色层串级柱分离方法，将铀材料样品中痕量钍吸附在强碱性阴离子交换柱上，大量的铀吸附在TBP色层柱上，而其它杂质元素既不被强碱性阴离子交换树脂吸附又不被TBP色层粉吸附，实现了微量钍与基体元素铀和其它杂质元素的分离，同时以230Th为钍同位素稀释剂，用热表面电离质谱法测定了铀材料样品中痕量钍的含量．测量结果显示，铀材料中钍的含量为（59．3±0．1）μg·g-1，扩展因子k=2，置信度为95％．Separation and purification methods for trace thorium and other impurity elements in uranium are important. Accurate and precise measurements can be made using isotope dilution mass spectrometry. In this study, we spiked samples with 230Th using alkaline anion exchange and tri-n-butyl phosphate （TBP） extraction chromatography stack columns for separating trace thorium and other impurity elements in uranium from an 8 mol L-1 nitric acid medium. In this separation method, thorium was adsorbed on the alkaline anion exchange resin, uranium was adsorbed on the TBP chromatography powder, and other impurity elements were not adsorbed on the alkaline anion exchange resin or the TBP chromatography powder. The purified thorium samples were analyzed using thermal ionization mass spectrometry. The results showed that the thorium content in uranium was （59.3±0.1）μg g-1, the expanded factor （k） was 2, and the confidence was 95%.

关 键 词：铀 微量钍 阴离子交换 TBP萃取色层 串级柱 同位素稀释质谱 

分 类 号：O641[理学—物理化学]