Spectrophotometric determination of iron (III) with oxine in pyridine aqueous medium

Abstract

Iron reacts with oxine to form a blue black soluble complex in 1040% pyridine aqueous medium. The complex had two absorption maxima at 460 mμ and 580 mμ and was stable for at least a week. Beer's law held for 0.5613.6 ppm of iron in 40% pyridine aqueous medium at pH 7.8 and the molar absorptivities at 460 mμ and 580 mμ were 4.7×103 and 3.7×103, respectively. Titanium(IV) and vanadium(V) gave a positive error by measuring at 460 mμ, but they did not at 580 mμ.The iron oxinate was also soluble in methanol, acetone, glycerine or aqueous sodium laurylbenzenesulfonate.Iron and aluminum in quartzites and clays were simultaneously, determined by measuring the absorbances at 375 mμ and 460 mμ.