The aim of this study is the development of a separation technique for geological samples, namely bismuthinites, with the goal to isolate Tl from excess amounts of Bi. This will enable an isotopic measurement of the Tl content on the ultra-trace level to identify a possible signature of Bi α-decay. The separation of Tl from other elements like e.g. Pb has been the subject of numerous studies. However, the separation of ultra-traces of Tl from bulk Bi had not yet been investigated sufficiently. This paper describes a separation technique for the system Bi/Tl for application to ultra-trace analysis. The separation technique uses a column chromatographic system, utilizing the specific redox behavior of Tl. The results show, that Tl can be successfully separated in appearance of vast excess amounts of Bi, showing recovery rates up to 96%. The developed procedure was successfully applied for the ultra-trace analysis on a number of bimuthinites using ICP-MS. On base of the results it is discussed, which prerequisites bimuthinite samples must fulfill to be suitable for the quantification of Bi alpha decay on base of the Tl isotopic ratio.

中文翻译：

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开发用于证明旧矿物样品中 209Bi α-衰变的 Bi/Tl 分离方案

本研究的目的是开发一种用于地质样品（即铋矿）的分离技术，目的是从过量的 Bi 中分离出 Tl。这将能够在超痕量水平上对 Tl 含量进行同位素测量，以确定 Bi α-衰变的可能特征。将 Tl 与其他元素（例如 Pb）分离已成为众多研究的主题。然而，尚未充分研究从块体 Bi 中分离超痕量 Tl。本文介绍了一种适用于超痕量分析的 Bi/Tl 系统分离技术。分离技术使用柱色谱系统，利用 Tl 的特定氧化还原行为。结果表明，当出现大量过量的Bi时，Tl可以成功分离，回收率高达96%。所开发的程序已成功应用于使用 ICP-MS 对多种铋铝矿进行超痕量分析。在结果的基础上，讨论了重辉石样品必须满足哪些先决条件才能适用于基于 Tl 同位素比对 Bi α 衰变进行量化。