Electron probe micro-analysis of oxygen in cordierite : potential implications for the analysis of volatiles in minerals
Electron probe micro-analysis of oxygen in cordierite : potential implications for the analysis of volatiles in minerals
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堇青石中氧的电子探针微量分析：对矿物中挥发物分析的潜在影响
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
Peter Gräser
中科院分区：
文献类型：
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作者：
Giles DROOP. David Plant And Peter Gräser;M. J. Rigby;Giles Droop;Peter Gräser
采用电子探针显微分析（EPMA）对30个表征良好的堇青石样品中的氧含量进行了分析。主要元素被认为是化学计量的，因此分析中任何剩余的氧都可以归因于挥发性氧，挥发性氧被定义为堇青石通道结构中h2o和/或co2中的氧。利用二次离子质谱法（SIMS）和傅里叶变换红外光谱法（FTIR）对EPMA挥发氧含量与同一样品的挥发氧含量进行比较。EPMA获得的数据与独立技术之间存在相关性。数据表明，轻元素，如氧，可以在电子探针上进行常规分析，其精确度接近其他成熟方法所获得的水平。除主要阳离子外，氧的EPMA为分析角闪石、云母和堇青石等矿物的h2o /OH -和/或挥发性氧含量提供了有价值的工具。然而，这种方法隐含的假设依赖于氧与主要阳离子的化学计量。如果应用非化学计量学，那么计算h2o或挥发性氧的方法就显得不充分。
The oxygen content of cordierite was analysed in 30, well-characterised samples, using electron probe micro-analysis (EPMA). The major elements were assumed to be stoichiometric and therefore any remaining oxygen from the analysis can be attributed to volatile oxygen, which is defined as the oxygen in H 2 O and/or CO 2 within cordierite’s channel structure. The EPMA volatile oxygen contents were compared to volatile oxygen contents obtained from the same samples using secondary-ion mass spectrometry (SIMS) and Fourier-transform infra-red spectroscopy (FTIR). There is a correlation between the data obtained by EPMA and the independent techniques. The data suggests that light-elements, such as oxygen, can be analyzed routinely on the electron microprobe with a degree of accuracy approaching the levels obtained by other, well-established methods. EPMA of oxygen, in addition to the major cations, provides a valuable tool for analyzing the H 2 O/OH − and/or volatile oxygen content of minerals such as amphiboles, micas and cordierite. The assumption implicit in this method, however, relies upon the fact that oxygen is stoichiometric with the major cations. If non-stoichiometry does apply then the method for calculating either H 2 O or volatile oxygen is rendered inadequate.