地热水锂组分快捷分离纯化及同位素测定  

Rapid Separation,Purification and Isotopic Determination of Lithium in Geothermal Water

作　　者：潘晟 孙亚莉 刘晓明[1] 岳雅慧[3] 赵平 PAN Sheng;SUN Yali;LIU Xiaoming;YUE Yahui;ZHAO Ping(Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;State Key Laboratory of Tibetan Plateau Earth System,Environment and Resources(TPESER),Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China)

机构地区：[1]中国科学院青藏高原研究所,北京100101 [2]中国科学院大学地球与行星科学学院,北京100049 [3]中国科学院青藏高原研究所青藏高原地球系统与资源环境全国重点实验室,北京100101

出　　处：《中国无机分析化学》2023年第1期31-37,共7页Chinese Journal of Inorganic Analytical Chemistry

基　　金：第二次青藏高原综合科学考察研究项目(2019QZKK0804);国家自然科学基金资助项目(U21A2015)。

摘　　要：锂是一种战略性矿产资源,青藏高原蕴藏着富锂地热水,锂同位素可以用来示踪其物质来源和演化过程。采用AG50W-X8阳离子交换树脂对地热水锂组分进行了快捷分离纯化,建立了利用多接收电感耦合等离子体质谱(MC-ICP-MS)法测定锂同位素的方法。移取适量的地热水样品加热蒸干,转化成0.20 mol/L HCl溶液后上柱,继续使用0.20 mol/L HCl纯化锂组分。当洗脱液中Na/Li比值≤1.2且锂的回收率超过99%时,可以在MC-ICP-MS上直接测定锂同位素比值。测定标准物质L-SVEC、IRMM-016和标准海水IAPSO的δ7Li值,结果分别为0.01‰±0.34‰、-0.02‰±0.46‰和30.75‰±0.35‰,与推荐值相符合。利用L-SVEC配制的标准溶液检查了MC-ICP-MS的长期稳定性,外精度要好于0.4‰(2σ)。在测定青藏高原地热水样品时,获得了准确的δ7Li值,可为青藏高原富锂地热水的成因机制研究提供技术支撑。Lithium mine is one of strategic resources in China.There are lithium-rich geothermal waters in the Tibetan Plateau.Lithium isotopic ratios could be used to tracing its origin and evolution.A convenient method for the lithium purification of geothermal waters was proposed by using AG50W-X8 cation exchange resin filling in quartz columns.As usual,lithium isotopes are determined by a multi collector inductively coupled plasma mass spectrometer(MC-ICP-MS).A quantitative of geothermal water was moved into a Teflon beaker,and then it was dried by a hot plate,re-dissolved in 0.20 mol/L HCl solution and infiltrated the quartz columns in sequence.The 0.20 mol/L HCl was selected to elute the resin.When the lithium recovery in eluate was greater than 99%,and Na/Li ratio lower to 1.2,the Li isotope can be determined directly by MC-ICP-MS without evaporation and elution again.Based on the method mentioned above,theδ7Li values of references L-SVEC,IRMM-016 and standard seawater IAPSO were determined were 0.01‰±0.34‰,-0.02‰±0.46‰and 30.75‰±0.35‰,which were consistent with the reference values,respectively.The long-term external reproducibility of theδ7Li value for reference L-SVEC was better than 0.4‰(2σ).The accurateδ7Li values were reported for geothermal waters in the Tibetan Plateau.The proposed method could support the genesis of Li-enriched geothermal waters in the Tibetan Plateau.

关 键 词：阳离子树脂 锂同位素比值 MC-ICP-MS 地热水 青藏高原 

分 类 号：O657.63[理学—分析化学] TH843[理学—化学]