MC―ICP―MS法测定锂同位素组成  

Determination of lithium isotope composition by multi-collector inductively coupled plasma mass spectrometry

作　　者：沙顺萍[1] 谈树苹[1] 白雪[1] 赵立飞[1] 赵胜洋[1] 徐马丽 马思齐 张琦琦 Sha Shunping;Tan Shuping;Bai Xue;Zhao Lifei;Zhao Shengyang;Xu Mali;Ma Siqi;Zhang Qiqi(China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院,北京102413

出　　处：《分析仪器》2022年第6期1-5,共5页Analytical Instrumentation

摘　　要：本研究以锂同位素分离工艺水相样品为研究对象,建立了MC-ICP-MS法测定中锂同位素组成的分析方法。考察了应用MC-ICP-MS测定锂同位素组成时基质含量、硝酸浓度、样品检测浓度锂盐阴离子的影响。结果表明,当Na/Li≤3时,(6)^Li/(7)^Li测量值和参考值间的相对误差≤0.4‰,当K/Li≤10时,(6)^Li/(7)^Li测量值和参考值间的相对误差≤0.3‰;为避免浓度差异和酸度差异对锂同位素测试的影响,样品与标准溶液之间浓度差异<12.5%且硝酸浓度保持一致;锂盐阴离子对锂同位素测定无显著影响。在优化条件下,对标准物质平行分析50次所获得(6)^Li/(7)^Li的相对标准偏差RSD为0.1‰。用热电离质谱(TIMS)对实际样品的测试进行了比对,测试结果在误差范围内一致。An instrumental analysis method for the determination of lithium isotope compositions in aqueous phase samples of the lithium isotopes separation using MC-ICP-MS was established,standard-sample-bracketing correction method was reported in detail,which included assessments of sodium content,potassium content,nitric acid concentration,concentration of samples,the ratio difference between standard and sample and the influence of different anions.The research results showed that the relative error between (6)^Li/(7)^Li measured value and reference value was less than 0.4‰when Na/Li≤3;the relative error between (6)^Li/(7)^Li measured value and reference value was less than 0.3‰when K/Li≤10;the analyte concentration in the sample and standard were matched within 12.5%,and the nitric acid concentration were matched to avoid the effect on the determination of lithium isotopes;the effect aroused by the mismatch of isotopic abundance ratio between sample and standards could be increased by-12%.The influence of different anions on the determination of lithium isotopes could be ignored.Under the optimized conditions,the lithium concentration of 800ng/mL,the relative standard deviations(RSD)of lithium isotopic ratios of the standard solution determined 50 times repeatedly was about 0.1‰.The results of lithium isotope compositions determined by TIMS showed an excellent agreement with the test results obtained by this method.The method of determining isotope abundance is reliable and the precision is high.

关 键 词：多接收电感耦合等离子体质谱 锂同位素 锂同位素分离 

分 类 号：O614.111[理学—无机化学] O657.63[理学—化学]