Purification, Recovery, and Laser-Driven Fluorination of Silicon from Dissolved and Particulate Silica for the Measurement of Natural Stable Isotope Abundances

Abstract : 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‰ for d30Si.
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Article dans une revue
Analytical Chemistry, American Chemical Society, 1996, 68, pp.3746-3750
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http://hal.univ-brest.fr/hal-00660855
Contributeur : Christina De La Rocha <>
Soumis le : mardi 17 janvier 2012 - 17:40:24
Dernière modification le : jeudi 11 janvier 2018 - 06:22:24

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  • HAL Id : hal-00660855, version 1

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Christina De La Rocha, Mark A. Brzezinski, M.J. Deniro. Purification, Recovery, and Laser-Driven Fluorination of Silicon from Dissolved and Particulate Silica for the Measurement of Natural Stable Isotope Abundances. Analytical Chemistry, American Chemical Society, 1996, 68, pp.3746-3750. 〈hal-00660855〉

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