岩石、水系沉积物和土样中三价铁的直接测定

Direct Determination of Ferric Iron in Rocks, Earth and Stream Sediment Samples

地质样品中的三价铁一般都采用测定全铁和亚铁后用差减法求得其含量。诚然,该分析结果将直接受亚铁的测定方法的准确度所左右。而就目前的亚铁分析方法来说,由于其本身存在着价态变化,受外界的干扰因素较多,测得的结果往往具有一定的相对性。因此,探索一个直接测定三价铁的分析方法是有其实用意义的。

This article brings up a method for the direct determination of ferric iron, using tiron as color reagent, o-phenanthroline is added with the acid mixture in the dissolution process to complex ferrous ions. A wave lenth which gives little absorbance with this red complex is selected for the colorimetry of the tiron complex. This method is simple and rapid, With high accuracy and precision. RSD% (n= 10) =1.70. It can be used for the direat determination of ferric iron in rocks, earth and stream sediment samples.