Spectrophotometric determination of trace amounts of iridium with Leuco-Crystal Violet

Abstract

The method for the spectrophotometric determination of Ir(III, IV) with Leuco-Crystal Violet(LCV) was improved both in simplicity and in precision, allowing wider application in practical use. Samples are treated with HCl and HNO₃ in the presence of NaCl, allowed to react with LCV purified by recrystallization and silica gel chromatography, and finally subjected to color development in acetate buffer solution containing hydroxylamine. Beer's law holds over the concentration range, 350μgIr/10ml solution. Fifteen runs with 1.87μgIr/ml solution gave an average absorbance of 0.501, with a relative standard deviation of 0.45%.