关键词: Si同位素, 高精度分析方法, 碱熔法, 地质储库硅同位素组成

Abstract: With the modification of Alkali fusion method for digesting silicates and the development of the multi-collection inductively coupled plasma mass spectrometer (MC-ICP-MS), the silicon isotopic analysis methods have been significantly improved in recent years. The analytical precision of δ³⁰Si (2SD) is better than ±0.10‰, compared with ±0.15‰-±0.30‰ by gas mass spectrometer (GS-MS) in earlier studies. It enables us to distinguish the minor fractionation of Si isotopes during the
high temperature processes; and also avoid using hazardous chemical such as fluoride. For the in situ determination of δ³⁰Si, the analytical precision of secondary ion mass spectrometry (SIMS) and femtosecond laser ablation (fs LA) also have been modified to be ±0.10‰-±0.22‰. This article reviewed the progress in silicon isotope analysis in the past decades, and discussed the establishment of high precision silicon isotope analysis method under wet plasma condition using MC-ICP-MS. Then we compared the silicon isotopic compositions of standard reference materials in different laboratories, and finally summarized the range of δ³⁰Si in major geological reservoirs, e.g., BSE, Earth crust and Meteorites.

Key words: silicon isotopes, high precision analytical method, alkali fusion, δ30Si in major geological reservoirs