Thermal decomposition of barium sulfate-vanadium pentoxide-silica glass mixtures for preparation of sulfur dioxide in sulfur isotope ratio measurements
Thermal decomposition of barium sulfate-vanadium pentoxide-silica glass mixtures for preparation of sulfur dioxide in sulfur isotope ratio measurements
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DOI：
10.1021/ac00257a046
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发表时间：
1983-05
影响因子：
7.4
通讯作者：
Fumitake. Yanagisawa;H. Sakai
中科院分区：
文献类型：
--
作者：
Fumitake. Yanagisawa;H. Sakai
本文详细研究了以前报道的用于制备SO/sub 2/ In硫同位素比测量的BaSO/sub 4/-V/sub 2/O/sub 5/-SiO/sub 2/的热分解过程，对该过程的某些部分进行了修改，并对反应机理的某些方面进行了定义。确定SO/sub 2/的/sup 18/O///sup 16/O比必须保持恒定，以便在S同位素比的质谱测定中对由于/sup 32/S/sup 16/O/sup 18/O/sup +/和/sup 34/S/sup 16/O/sub 2///sup +/引起的离子流重叠的影响应用一致的校正因子。X-射线衍射分析表明，V/sub 2/O/sub 5/是降低BaSO/sub 4/分解温度的关键。适量的SiO/sub 2/似乎有助于SO/sub 2/的平稳和完全演化;然而，过量的SiO/sub 2/降低了SO/sub 2/产率，并可能阻止熔融。过量的V/sub 2/O/sub 5/也降低了SO/sub 2/产率，可能是因为它使反应混合物沸腾。SiO/sub 2//V/sub 2/O/sub 5/为1时，SO/sub 2/的演化最完整、平稳。通过这种方法产生的SO/sub 2/more »纯度足够高，可以直接用质谱法进行分析。«少
A previously reported procedure for the thermal decomposition of BaSO/sub 4/-V/sub 2/O/sub 5/-SiO/sub 2/ for the preparation of SO/sub 2/ in sulfur isotope ratio measurements has been studied in detail, certain portions of the procedure have been modified, and certain aspects of the reaction mechanism have been defined. It was determined that the /sup 18/O//sup 16/O ratio of SO/sub 2/ must be kept constant in order to apply a consistent correction factor for the effect of overlap of the ion currents due to /sup 32/S/sup 16/O/sup 18/O/sup +/ and /sup 34/S/sup 16/O/sub 2//sup +/ in the mass spectrometric determination of S isotope ratio. X-ray diffraction studies of the solid reaction products indicated that the V/sub 2/O/sub 5/ is essential in lowering the decomposition temperature of BaSO/sub 4/. In moderate amounts, SiO/sub 2/ seemed to aid in the smooth and complete evolution of the SO/sub 2/; however, excessive SiO/sub 2/ lowered the SO/sub 2/ yield and probably prevented melting. Excess V/sub 2/O/sub 5/ also lowered SO/sub 2/ yields, probably because it boiled off the reaction mixture. A ratio of SiO/sub 2//V/sub 2/O/sub 5/ of 1 was considered to be the best for complete, smooth evolution of SO/sub 2/. SO/sub 2/ producedmore » by this method is pure enough to be directly analyzed by mass spectrometry.« less