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一、前言应用U-Th-Pb法测定矿物、岩石年龄,主要根据Pb/U、Pb/Th同位素比值而得,因此精确测定U、Th、Pb的含量及同位素组成是一个极其重要的问题。微量铅的测定方法较多,有离子交换分离示波极谱法、阳极溶出法、微电解法、打萨宗萃取比色法等。但要从矿物岩石中分离出微量铅,操作极为复杂,还存在一些缺点:需要加入大量的共沉剂及隐蔽剂(包括剧毒性的氰化钾),这样除了使铅的回收率降低外,
I. Foreword The U-Th-Pb method is used to determine the age of minerals and rocks. It is mainly based on the Pb / U, Pb / Th isotope ratios. Therefore, it is an extremely important issue to accurately determine the contents of U, Th and Pb and the isotopic compositions. Determination of trace lead more methods, there are ion-exchange separation oscillopolarography, anodic stripping, micro-electrolysis, Sassafras extraction colorimetric method. However, the separation of trace amounts of lead from mineral rocks is extremely complicated and involves a number of disadvantages: large amounts of co-settling agents and entrap agents (including highly toxic potassium cyanide) need to be added, so that in addition to reducing lead recovery ,