电化学分析法直接测定岩石矿物中二价铁和三价铁

Direct Determination of Fe(Ⅲ) and Fe( Ⅱ) in Rocks and Minerals by Electroanalytical Methods

是出了在同一份样品溶液中采用电位滴定法和库仑滴定法分别直接测定Fe^(3+)和Fe^(2+)的方法。在实验确定的最佳条件下测定0.20～5.00mgFe^(3+)的RSD％小于0.90(n=5);测定0.032～10.0mgFe^(2+)的RSD％小于0.86(n=5)。用岩石一级标准物质和单矿物标准物质检验并参加标准物质GSR 7～12的协作定值,结果良好。

Fe(Ⅲ ) and Fe(Ⅱ ) were directly determination by potentiometric and coulometric titrations respectively in the same solution aliquot. Experimental conditions were optimized for the range of 0. 2~5mg Fe(Ⅲ)(RSD<0. 90%,n = 5) and 0. 032~10mg Fe( Ⅱ ) (RSD<0. 86%,n= 5) in 40ml volume. The method has been examined by analysing a series of rock and mineral standard reference samples and the results obtained agreed well with the recommended values. The method should be especially suitable for samples which are only available in small amounts such as mineral separates.