土壤样品镉同位素分析中Cd与Sn有效分离方法的改进  

Improvement on Effective Separation between Cadmium and Tin in Soil Samples for the Determination of Cadmium Isotopic Composition

作　　者：段桂玲[1] 段瑞春[1] 谭娟娟[1] 顾涛[1] 邵长生[1] 路韬[1] 

机构地区：[1]中国地质调查局武汉地质调查中心,湖北武汉430205

出　　处：《岩矿测试》2016年第1期10-16,共7页Rock and Mineral Analysis

基　　金：中国地质大调查项目--长江中游城市群活动构造与地壳稳定性评价(1212011120097)

摘　　要：保证Cd的高回收率以及彻底的Sn干扰去除是获得精确镉同位素组成的前提,目前报道的多种Cd分离与纯化方法获得的Cd回收率有较大差异（42.6%~99.8%）,且去除Sn干扰的效果也不同（去除率在87.8%~97.4%之间）,Cd回收率和Sn去除率均不理想。本文对前人报道的分离方法进行对比实验,发现0.1 mol/L氢溴酸-0.5 mol/L硝酸是分离Cd和Sn的有效试剂,增加该组混合酸的用量可淋洗出样品中更多的Sn且不会损失Cd,当混合酸的淋洗用量增加至30 mL时,Sn的淋洗率达到99.8%以上,Cd的回收率亦达到99.0%±0.5%,可满足土壤样品镉同位素的测定要求。本工作为获得高精度的镉同位素组成奠定了基础,为研究土壤环境中镉的污染来源提供了技术手段。In order to determine Cd isotopic composition accurately,the key is to guarantee Cd recovery and reduce Sn interference. The recoveries of Cd with various separation and purification methods reported by previous studies show a large range variation from 42. 6% to 99. 8%,and the removal efficiency of Sn interference are various（ 87. 8%- 97. 4%）. Both the Cd recovery and Sn removal are not ideal. Reported in this study,0. 1 mol/L HBr- 0. 5 mol / L HNO3 mixture was determined to be a more effective solution to separate Cd from Sn. By increasing the amount of this mixture during leaching,more Sn can be removed from the samples without Cd loss. When30 m L of mixture is used during leaching,more than 99. 8% Sn can be leached out from the sample and the Cd recovery is 99. 0% ± 0. 5%. This method can be utilized for Cd isotope analyses of soil samples,offering new insight for high-precision Cd isotope measurement and serving as a technical method for Cd pollution tracing in the study of environmental soil.

关 键 词：土壤样品 镉同位素 锡 离子交换 化学预处理 电感耦合等离子体质谱法 

分 类 号：S151.93[农业科学—土壤学] O614.242[农业科学—农业基础科学]