绝对质谱法测量钐同位素丰度  

Absolute Determination of Samarium Isotopic Abundance by Multiple-collector Inductively Coupled Plasma Mass Spectrometry

作　　者：周涛[1] 赵墨田[2] 李金英[1] 王军[2] 赵永刚[1] 张继龙[1] 逯海[2] 方向[2] 

机构地区：[1]中国原子能科学研究院,北京102413 [2]国家标准物质研究中心,北京100013

出　　处：《分析化学》2005年第9期1272-1274,共3页Chinese Journal of Analytical Chemistry

基　　金：国家自然科学基金资助项目(No.20375009)

摘　　要：使用高浓缩同位素的152Sm和154Sm配制不同丰度的Sm基准溶液,对多接收电感耦合等离子体质谱(MC-ICPMS)的系统偏差进行校准,求出154Sm/152Sm的平均校准系数。采用指数函数式推算出其它同位素比的校准系数。对天然样品的测量结果进行校正,并与表面热电离质谱的测量结果进行了比较,主同位素对的丰度比误差小于0.03%。实验结果表明,MC-ICPMS测量的影响因素多,系统偏差较大,但是通过校正可以获得与表面热电离质谱一致的测量结果。通过实验,建立了MC-ICPMS的同位素丰度绝对测量方法。Standard solutions of different samarium isotope abundance were prepared by blending high concentrated isotope of ^152Sm and ^154Sm, which were measured by multiple-collector inductively coupled plasma mass spectrometry（MC-ICPMS） to gain the correction factor. In order to achieve better accuracy, solution concentration, nebulizer gas flow rate, sampling position and collision gas flow rate have been studied. Continuous measurement of standards and samples with constant conditions was needed for correction of results because of the instability of sampling system and ICP source. The same samples were determined using thernal ionized mass spectrometry （TIMS）. The measurement results of two methods were compared and the corrected results of main isotopic ratios were almost accordant better than 0.03%. The precision of MC-ICPMS results was comparative with that of TIMS, but the mass bias of latter was approximately an order of magnitude greater than that of MC-ICPMS. By correction of isotopic standards, the absolute measurement method of MC-ICPMS was established.

关 键 词：多接收电感耦合等离子体质谱 绝对测量 钐 同位素丰度 测量方法 绝对质谱法 MC-ICPMS 电感耦合等离子体质谱 热电离质谱 校准系数 

分 类 号：O657.63[理学—分析化学] TL27[理学—化学]