(LP)MC-ICPMS方法精确测定液体和固体样品的Sr同位素组成  

Precise measurement of Sr isotopic composition of liquid and solid base using (LP)MC ICPMS

作　　者：韦刚健[1] 梁细荣[1] 李献华[1] 刘颖[1] 

机构地区：[1]中国科学院广州地球化学研究所,广东广州510640

出　　处：《地球化学》2002年第3期295-299,共5页Geochimica

基　　金：中国科学院知识创新工程重要方向项目(KZCX2-102)

摘　　要：MC-ICPMS是近年发展起来的高精度固体同位素分析仪器,利用MC-ICPMS可以精确测定Sr同位素组成,与TIMS相比,分析效率明显提高;对于含有Rb的实际样品,在Rb/Sr比值较小时(Rb/Sr<0.001),可以通过Rb扣除获得准确的87Sr/86Sr比值,而当Rb含量较高时,可以通过建立Rb/Sr与87Sr/86Sr偏差值的线性关系进行再一次校正,同样也可以获得准确的87Sr/86Sr比值。通过这种校正关系,可以直接分析固体微区的Sr同位素组成。Multi Collector Inductively Coupled Plasma Mass Spectrometry (MC ICPMS), a powerful tool for solid isotopic measurement developed in recent year, can precisely measure Sr isotopic composition with much higher efficiency than Thermal Ionization Mass Spectrometry (TIMS). As for the sample with Rb, the creditable 87Sr/86Sr can be obtained by subtracting the interference of Rb when Rb/Sr ratios are less than 0.001. However, when the Rb content is high, especially when Rb/Sr > 0.01, an extra calibration should be made. Usually an empirical linear regression between Rb/Sr ratios and Δ87Sr/86Sr, the deviation of the measured 87Sr/86Sr from its true ratio, should be established before hand based on some standard Sr solution test. According to the empirical linear regression, the true 87Sr/86Sr ratios are available. Furthermore, such calibration could help the in situ measurement of Sr isotopic compositions for the solid samples by laser ablation.

关 键 词：MC-ICPMS SR同位素 激光原位分析 锶 铷同位素 多接收器等离子体质谱仪 

分 类 号：P575[天文地球—矿物学] P597[天文地球—地质学]