| 陨石中铼锇同位素化学分离过程的几个重要影响因素 |
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| 引用本文： | 江小英,王桂琴,彭丽.陨石中铼锇同位素化学分离过程的几个重要影响因素[J].极地研究,2013,25(4):414-424. |
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| 作者姓名： | 江小英 王桂琴 彭丽 |
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| 作者单位： | 1.中国科学院广州地球化学研究所，同位素地球化学国家重点实验室，广东 广州 510640；
;2.中国科学院大学，北京 100049 |
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| 基金项目： | 国家自然科学基金重点项目 |
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| 摘 要： | 本文针对陨石中铼锇同位素比值高精度测定，选取6块不同类型的普通球粒陨石（吉林陨石、信阳陨石、武安陨石、肇东陨石、河北陨石、荷叶塘陨石）和两块铁陨石（南丹铁陨石和T-5）进行预处理和化学过程的一些条件实验。实验结果表明，陨石金属表面的锈迹清洗使用1M的HCl效果更佳；对于样品溶解，逆王水溶解效果比浓硝酸好,高温溶样熔解彻底，常温状态下仅能溶解出约30%的陨石样品中的Os；微蒸馏二次纯化可提高Os测定信号的稳定性和精度；稀释剂的浓度及加入量应与样品匹配，且达到平衡状态是高精度和高准确度的保障；普通球粒陨石取样范围在0.1g-0.3g (即样品中Os的绝对含量为100ng)即可获取最佳信号强度和精度；本次实验全流程空白Os可控制至0.5~81pg，Re可控制至4～77pg采用同位素稀释法，当187Os/188Os比值的精度最小可至4ppm（n=120，2se）。
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| 收稿时间： | 2013-03-25 |
SEVERAL IMPORTANT FACTORS CONCERNING THE CHEMICAL SEPARATION OF RE-OS ISOTOPES IN METEORITES |
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| Jiang Xiaoying,Wang Guiqin,Peng Li.SEVERAL IMPORTANT FACTORS CONCERNING THE CHEMICAL SEPARATION OF RE-OS ISOTOPES IN METEORITES[J].Chinese Journal of Polar Research,2013,25(4):414-424. |
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| Authors: | Jiang Xiaoying Wang Guiqin Peng Li |
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| Abstract: | Some important conditions are discussed in this paper for high-precision measurement of Re and Os in meteorites by means of isotope dilution technique. We have measured the Re-Os system for samples of whole rock from six ordinary chondrites and two Iron meteorites. The result shows that 1M HCl can be fit for removing rust of metal surface. And the high digestion-temperature are necessary for digestion of meteorites. The normal condition can be dissolved out only about 30% of meteorite samples Os. However, microdistillation is not very necessary after Re-Os separation by means of distillation technique but this secondary purification can improve the stability and accuracy of the signal. In contrast with samples dissolved by HNO3, the intensity of Os in samples dissolved by reverse aqua regia is far stronger. When the concentration and quantity of spikes are proper and there is a perfect equilibrium between samples and spikes, we can attain good data generally consistent with the references’. The minimum quantity of ordinary chondrites is 0.1~0.3g or the absolute abundance of Os is 100ng during digestion with low blank levels (Re 4~77pg, Os 0.5pg ~2ng) when the standard deviation of 187Os/188Os can be limited to ±4ppm(n=120, 2se). |
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| Keywords: | meteorite Re-Os isotope dilution technique TIMS |
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