海水中钕同位素的测定及其在水团混合中的指示意义  

Measurement of Neodymium Isotope in Seawater and Its Significance in Mixing of Water Masses

作　　者：车宏 张劲 赵志琦[3] 何会军[1] CHE Hong;ZHANG Jing;ZHAO Zhi-Qi;HE Hui-Jun(Key Laboratory of Marine Chemistry Theory and Technology,Ministry of Education,Ocean University of China,Qingdao 266061,China;Earth and Environmental System,Graduate School of Science and Engineering,University of Toyama,Toyama 9308555,Japan;State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,China Academy of Sciences,Guiyang 550002,China)

机构地区：[1]中国海洋大学化学化工学院海洋化学理论与工程技术教育部重点实验室,青岛266061 [2]日本国立富山大学理学部生物圈环境科学科,日本富山9308555 [3]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550081

出　　处：《分析化学》2018年第9期1393-1399,共7页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金项目(Nos.41530965;41276071)资助~~

摘　　要：海水中的钕(Nd)同位素性质稳定,被广泛用于海洋学过程的研究。由于海水中Nd含量很低,且在测定过程中易受钐(Sm)的影响,因此富集和纯化成为海水中Nd同位素分析的必要步骤。传统的分离方法通常是利用氢氧化铁共沉淀法富集海水中的稀土元素(REEs),再用LN-C50-A树脂对Nd进行分离纯化。但富集过程较为耗时。本研究采用NOBIAS螯合树脂对海水中的稀土元素进行富集,优化了上样pH值、NOBIAS PA1螯合树脂淋洗酸浓度、LN-C50-A树脂淋洗酸体积等实验条件。结果表明,当pH=4. 7时,NOBIAS PA1螯合树脂对钕的回收效率大于99%; LN-C50-A树脂对钕分离纯化的回收效率大于93%。本方法重现性好(RSD<1.5%,n=3),且系统误差对钕同位素的测定无显著影响(RSD<5%,n=5),能满足海水中钕及其同位素分析精度的要求。Neodymium(Nd)isotopes are widely used for oceanographic processes because of its stable properties in nature.Due to the low concentration of Nd in the seawater,pre-separation and enrichment are necessary in the analysis of Nd isotopes.The traditional separation method usually uses co-precipitation with hydrous Fe oxide to separate rare earth elements(REEs),and LN resin to separate and purify Sm and Nd,respectively.But the concentration process is time-consuming.In this work,a concentration method for REEs in seawater was developed on the basis of NOBIAS resin.The experimental conditions of this method,such as the range of pH,elution acid concentration of NOBIAS resin,and elution acid volume for LN-C50-A resin were optimized.The results indicated that,at pH 4.7,the recovery of Nd was about 99%when pre-concentrated with NOBIAS resin and the recovery of Nd was over 93%when purified with LN-C50-A resin.The method showed an excellent experimental reproducibility(RSD<1.5%;n=3)and a very low systematic error(RSD<5%,n=5)in the determination of Nd and its isotope.

关 键 词：海水 钕同位素 LN-C50-A树脂 NOBIAS螯合树脂 影响因素 

分 类 号：X834[环境科学与工程—环境工程] P734.4[天文地球—海洋化学]