X射线荧光光谱法测定水系沉积物ESR测年样品U、Th、K含量

Sediment U,Th,K content analyzed using X-ray fluorescence spectrometry for ESR dating samples

环境剂量率的准确测量是获得可靠ESR年代的关键问题之一。本文采用X射线荧光光谱法,在低X射线功率和基体效应消除基础上定量测定水系沉积物的U、Th、K含量,并与传统的α计数仪-原子吸收光谱法比较,两种方法获得的环境剂量率差异在5%以内。这表明X射线荧光光谱法可用于水系沉积物ESR测年中的U、Th、K含量测定,同时该测量方法具有测定速度快、可重复、无损测量等优点。

The accurate measurement of dose rate is the key issues to obtain reliable ESR age. In this article, we used X-ray fluorescence spectrometry to determine the U, Th, K content of the fluvial sediments. And the standard working curves were established using the national rock reference material. Setting the lower X-ray power and the matrix effect, U, Th, K content in the fluvial sediment were investigated. The results show that the method recovery rate of U and Th is less than 15 %. Comparing with the measurement data from the α-counting and Atomic Spectrometry analysis, the dose rate difference is less than 5 %. It shows that the X-ray fluorescence spectrometry method can fit for the requirement for obtaining the U, Th, K content of fluvial sediment for ESR dating.