中子活化分析法测定地质样品中的稀有分散元素

Determination of Rare and Dispersed Elements in Geological Samples by Mini-reactor Neutron Activation Analysis

国土资源大调查的新一轮地球化学填图新增30余种元素中包括有稀散元素,要求建立相应的高新分析测试技术。为了避免化学方法和过程引入的空白污染,本文研究了微堆中子活化分析测定稀有分散元素Cs、Ga、Hf、In、Rb、Sc、Ta、Zr的纯仪器测量条件和影响因素。通过超热中子活化分析,使Cs、Ga、In、Ta、Zr等元素的检出限得以改善,分析周期也有一定的缩短。对循环中子活化方法的条件进行了研究和运用,实现了Hf和Sc快速分析。

Rare and dispersed elements belong to the new added 37 elements in geochemical mapping of the new round of land resources survey in China.The situation required that new analytical techniques must to be established.In order to adapt to this demand,this paper studied the method to determine rare and dispersed elements in geochemical samples by instrumental neutron activation analysis on miniature neutron source reactor(MNSR).This paper discussed the instrumental measurement conditions and influencing factors of the determination of rare and dispersed elements Cs,Ga,Hf,In,Rb,Sc,Ta,Zr by mini-reactor neutron activation analysis so as to optimize processes of the method.By using the method of epithermal neutron activation,the limit of detection of In,Ta,Zr can be improved,and the analysis cycle has been shortened in some extent.The cyclic neutron activation method were studied,so that rapid analysis of Hf and Sc has been realized by using this technology.The introduced method can be popularized and used to analyze rare and dispersed elements in geological samples,in which relative standard deviation of the target elements is within 3%~13%,both the detection limit and the accuracy meet the requirements of the geochemistry standards.