Sm-Nd同位素准确测定的影响因素分析  

Factors of In fluence on Accurate Determination of Sm-Nd Isotopic Ratios

作　　者：刘宇昂[1] 崔建勇[1] 王晓明[1] 裴玲云[1] 汤书婷[1] 

机构地区：[1]核工业北京地质研究院,北京100029

出　　处：《铀矿地质》2015年第6期606-610,共5页Uranium Geology

摘　　要：通过对Sm-Nd同位素测定的流程分析,探讨了对Sm-Nd同位素分析的影响因素。采用HF+HNO3+H3BO3溶解样品,可有效地消除氟化物对REE回收率的影响;样品容器和分离柱的本底是全流程本底的主要来源;根据同位素稀释法误差倍增曲线,合理加入稀释剂的量可有效提高147Sm/144 Nd测定的准确度;稀释剂加入量对稀释法同位素比值测定的影响主要来源于稀释剂同位素组成测定的不确定度,通过数学迭代法,可对稀释剂同位素组成测定的质量分馏效应进行有效校正,提高稀释剂同位素组成的准确性。Factors of influence on accurate determination Sm-Nd isotopic ratios was discussed by analyzing the determination process.Insoluble fluoride formed during samples digestion with HF and HNO3 was eliminated by adding 3% H3BO3solution（Fluorides can co-precipitate REE）,thus improved the recovery of REE.The main resources of total procedure blanks are the test ware and the separation column which are reused after cleanning.The influence of err propagation in the isotope dilution was analyzed.The added amount of spike according to error magnification factor can improved the accuracy of ^147Sm/^144Nd.The uncertainties of isotopic composition of spike from mass fractionation affect the accuracy of spiked ^143 Nd/^144Nd.The mass fractionation of spike can be corrected by an iterative procedure.

关 键 词：影响因素 SM-ND 测定 

分 类 号：P618.92[天文地球—矿床学] P597.1[天文地球—地质学]