Carius管溶样-负离子热表面电离质谱准确测定辉钼矿铼-锇同位素地质年龄  

Precise Re-Os Dating for Molybdenite by ID-NTIMS with Carius Tube Sample Preparation

作　　者：杜安道[1] 赵敦敏[2] 王淑贤[1] 孙德忠[1] 刘敦一[2] 

机构地区：[1]国家地质实验测试中心,北京100037 [2]中国地质科学院地质研究所,北京100037

出　　处：《岩矿测试》2001年第4期247-252,共6页Rock and Mineral Analysis

基　　金：科技部项目 (G99-A - 9a) ;国家自然科学基金项目 ( 4 9973 0 17)

摘　　要：将样品、混合稀释剂和逆王水加入到Carius管中 ,于 2 3 0℃溶样 1 0h。利用蒸馏法分离Os,萃取和阴离子交换法分离Re。采用负离子热表面电离质谱精确测定了所研制的年龄标准参考物辉钼矿 (HLP)的Re Os年龄。对取自 1 2个小瓶中 1 7个样品所测平均年龄为 2 2 1 .3±0 .3Ma ,置信度 95 %。中值年龄和平均绝对偏差为 2 2 1 .3 4± 0 .1 2Ma。美国克罗拉多州立大学AIRIE小组 1 9次单独取样所测HLP的平均年龄为 2 2 1 .3± 1 .0Ma,置信度 95 %。中值年龄和平均绝对偏差为 2 2 1 .3 4± 0 .2 4Ma。A precise Re Os dating method for molybdenite by ID NTIMS with Carius tube sample preparation was presented in this paper. The sample was digested with mixed spikes and reverse aqua regia in a Carius tube at 230 ℃. Os was purified using normal distillation and micro distillation. And Re was purified using acetone extraction and anion exchange chromatography. Isotope ratios were determined by NTIMS. The method has been applied to Re Os age determination in a standard reference molybdenite HLP powder. Seventeen samples from twelve bottles were analyzed over a period of six months. The average Re Os age of this standard reference molybdenite sample analyzed by this method was 221.3 ± 0.3 Ma with 95% confidence limit. The median age with mean absolute deviation was 221.34 ± 0.12 Ma. The result from this method is in agreement with that from AIRIE group of Colorado University USA.

关 键 词：Carius 铼 锇 辉钼矿 微蒸馏 同位素年代学 负离子热表面电离质谱 

分 类 号：P597[天文地球—地球化学] P578.291[天文地球—地质学]