质谱学报2017，Vol.38Issue(5)：567-573,7.DOI:10.7538/zpxb.2016.0190
热电离质谱(TIMS)测定Ca同位素时Sr干扰影响的实验评价
Experimental Assessing about Sr Interference Effect on Ca Isotope Measurements on Thermal Ionization Mass Spectrometry
摘要
Abstract
Calcium and strontium are all alkaline earth metals.Because of their similar chemical properties,it is difficult to separate strontium from calcium completely during chemical separation processes.Thus,the calcium cut after chemistry usually contains some strontium.Besides,it is known that Sr double charges,such as 88Sr2+,86Sr2+,84Sr2+,could be treated as interferences to 44Ca+,43Ca+,42Ca+ respectively,during calcium isotope measurements on thermal ionization mass spectrometry (TIMS).To evaluate this interference effect,we designed an experiment and ran a series of samples on TIMS using single Ta filaments.IAPSO seawater standard was used in the experiment,and a certain amount of Sr standard solution was added in it to make the mixture has a Ca/Sr ratio about 5.The mixture was then divided into several equal solutions and pass through the calcium columns respectively.For each column,different percentage of Sr cut was collected together with whole Ca cut and calcium ratio was determined thereafter on TIMS using single Ta filaments.As the TIMS measurements' result,all of those samples,although having different Ca/Sr ratios,display unique calcium isotopic compositions with IAPSO seawater standards that our laboratory monitoring for a long time within error.Based on the results,we conclude that currently,for the most geology samples,that usually contain a Ca/Sr ratio＞5,Sr interference effect on Ca measurement on TIMS using single Ta filament is very limited,which could be neglected.Besides,the chemical separation procedure for Ca could be improved,through increasing the concentration of the leaching acid,better Ca peak shape and efficiency can be reached.关键词
Ca同位素/Sr干扰/Ta单带/Ca/Sr比值Key words
calcium isotope/Sr interference effect/Ta single filament/Ca/Sr ratio分类
化学化工引用本文复制引用
张晨蕾,祝红丽,刘峪菲,刘芳,张兆峰..热电离质谱(TIMS)测定Ca同位素时Sr干扰影响的实验评价[J].质谱学报,2017,38(5):567-573,7.基金项目
国家自然科学基金重大项目(41490632) （41490632）
国家自然科学基金重点项目(91328204) （91328204）
国家自然科学基金面上项目(41373007) （41373007）
同位素地球化学国家重点实验室项目(SKLIG-JY-12-01,SKLIG-JY-13-03,SKLIG-KF-13-03)资助 （SKLIG-JY-12-01,SKLIG-JY-13-03,SKLIG-KF-13-03）
