SEVERAL IMPORTANT FACTORS CONCERNING THE CHEMICAL SEPARATION OF RE-OS ISOTOPES IN METEORITES

doi:10.3724/SP.J.1084.2013.00414

Abstract

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).

Key words: meteorite, Re-Os, isotope dilution technique, TIMS

Jiang Xiaoying，Wang Guiqin，Peng Li. SEVERAL IMPORTANT FACTORS CONCERNING THE CHEMICAL SEPARATION OF RE-OS ISOTOPES IN METEORITES[J]. ADVANCES IN POLAR SCIENCE, 2013, 25(4): 414-424.

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