铷—锶年龄测定中样品制备的一种新方法

在铷—锶年龄测定中,制样工作占有重要地位。要从千变万化的岩石、矿物样品中制出能满足质谱测定的Rb、Sr同位素样品,要使Rb~(87)和Sr~(87)这对同量异位素完全分离,就需要有一个简便、完备的方法。国内、外的Rb—Sr同位素实验室大都采用离子交换分离制样法。 为了满足高精度、高灵敏度及高自动化程度的

A New Method for Sample Preparation in Rb-Sr Dating

Based on the results of studing a lot of rock samples by radioactive trace- experiments, a rapid method for sample preparation in Rb-Sr dating has been suggested. A new type of ion exchange column called "double bed type" has been designed. In this column AG 50W × 8 (200-400 mesh) ion exchange resin has not only been used but also an inorganic ion exchanger-ZrP (prepared in our laboratory), the former for seperating Rb and Sr from the main elements in rock and mineral, the latter for removing a trace Rb in Sr isotopic samples. For raising the efficiency of Rb-Sr separation, the techniques of burning organic. carbon at high temperature and extracting Rb and Sr from the salt and oxide by H2O have been taken, too. In such a way, the separation of Rb and Sr can be completed rapidly. It takes about 8 hours to finish the whole procedure. Only in the whole tun is 38. ml the total volume of acid elution. According to the results ofv analysing a standard K-feldspar NBS 70a; 45 samples of"granite, metamorphic and sedi- mentary rocks and ten minerals, it has been fonad that the method may be applied successfully to many kinds of rock and mineral.