Cr同位素作为一个新的研究手段,在天体化学领域中主要应用于追溯太阳系早期历史演化和定年.Cr同位素组成测定的主要技术是二次离子探针、热电离质谱和多接收等离子质谱,本文对这些分析技术的特点和发展作了论述.随着分析技术的发展,目前对ε(53Cr)和ε(54Cr)测定精度分别达到6 ppm和12 ppm(2σ).高精度Cr同位素比值测定可以对陨石物质中更微细的Cr同位素变化进行测定,近几年的高精度Cr同位素测定数据,对53Cr和54Cr在太阳系中的分布是否均一及它们所指示的成因意义提出了新的认识.高精度Cr同位素组成测定和研究将为我们带来许多新的发现和突破,去重新认识和评价Cr同位素在太阳系中的分布规律及成因模式.%Chromium isotope compositions have been widely applied in cosmochemistry and are a record of the early evolution of the Solar System. The major methods employed to measure Cr isotopic compositions are SIMS, TIMS and MC-ICPMS. This paper reviews the characteristics and development of these analysis techniques. With development of analytic techniques, the current analytical precisions for e(53Cr) and ε(54Cr) are 6 and 12 ppm (2 σ) , respectively. The subtle variation in Cr isotopic compositions in extraterrestrial materials can be determined by highly precise measurement of Cr isotopes. This advantage provides a new way to further clarify and evaluate the origin and distribution of 53Cr and 54Cr in the Solar System.
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