铼-锇同位素分析中试样化学预处理方法进展

Progress in Chemical Separation and Purification for Re and Os Isotopic Analyses

评述了用于Re -Os同位素体系分析的化学前处理技术的发展。简要介绍了卡洛斯管熔样法、Os的CCl4提取、溴提取和微蒸馏方法。卡洛斯管封闭熔样方法 ,有效地防止了Os的挥发损失和保证了Os同位素平衡 ,是一种很有发展前景的熔样方法。蒸馏法仍是分离和纯化Os的有效方法 ,溶剂 (CCl4)提取和溴提取法在许多实验室里应用 ,而微蒸馏则是Os的二次纯化的主要方法。Re的化学分离和纯化仍是离子交换和萃取法。引用主要文献 2 9篇。

The development of chemical procedures for the precise determination of Re Os isotopic compositions is reviewed. The Carius tube digestion, solvent extraction of Os by CCl 4, selective extraction of Os by liquid bromine, and micro distillation were briefly described. It is well known that osmium can easily escape as osmium tetraoxide even in weakly oxidative conditions, which is one of the major reasons why osmium abundance determination has been difficult. However, when reactions are accomplished in sealed Carius tubes, the loss of Os can be prevented. The Carius tube digestion technique also promotes the complete equilibrium of Os in the sample with Os in the spike. For the reasons mentioned above the Carius tube technique has replaced other conventional methods, such as microwave digestion and alkaline fusion in some laboratories. Although distillation is an effective method for separating and purifying Os solvent extraction by CCl 4 and selective extraction by liquid bromine have been developed. The further purification of Os is accomplished by a micro distillation technique. Separation and purification of Re is achieved by anion column exchange or solvent extraction techniques.