Purification, recovery, and laser-driven fluorination of silicon from dissolved and particulate silica for the measurement of natural stable isotope abundances
Purification, recovery, and laser-driven fluorination of silicon from dissolved and particulate silica for the measurement of natural stable isotope abundances
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DOI：
10.1021/ac960326j
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发表时间：
1996-11-01
影响因子：
7.4
通讯作者：
DeNiro, MJ
中科院分区：
文献类型：
--
作者：
DelaRocha, CL;Brzezinski, MA;DeNiro, MJ
本文报道了一种从生物和岩石颗粒物及溶解态硅酸中提纯、回收和测定硅同位素丰度的方法。提纯是指将溶解态硅酸与天然沃茨中的溶解态硅或用氢氟酸溶解颗粒硅所产生的溶解态硅反应。然后通过与三乙胺盐酸盐反应定量沉淀所得硅钼酸，通过逐步燃烧干燥的沉淀物以二氧化硅形式回收硅，通过在氟基盐分解产生的纯氟下激光加热完成用于同位素分析的产物的氟化，使用可变温度冷阱低温分离所得四氟化硅与氟化氢和其它氢化物副产物，硅回收的产率对于沉淀为99.9%，对于纯化/重结晶程序大于95%。通过该程序处理的纯石英颗粒的同位素组成的重现性为δ（30）Si的+/-0.1 ‰。
A procedure for the purification, recovery, and determination of isotopic abundances of silicon from biogenic and lithogenic particulate matter and dissolved silicic acid is reported, Purification involves the reaction of acid molybdate with dissolved silicon in natural waters or that produced by the dissolution of particulate silica by hydrofluoric acid. The resulting silicomolybdic acid is then quantitatively precipitated by reaction with triethylamine hydrochloride, The silicon is recovered as silicon dioxide through stepwise combustion of the dried precipitate, Fluorination of the product for isotopic analysis is accomplished by laser heating under pure fluorine generated by the decomposition of a fluorine-based salt, The resulting silicon tetrafluoride is separated from hydrogen fluoride and other fluorination byproducts cryogenically using a variable-temperature cold trap, Yields for silicon recovery are 99.9% for precipitation and greater than 95% for the purification/fluorination procedure. Reproducibility of the isotopic composition for pure quartz granules processed through the procedure is +/-0.1 parts per thousand for delta(30)Si.