Spectrophotometric Determination of Microamounts of Iridium(IV) with 3-Hydroxy-2-methyl-1-phenyl-4-pyridone or 3-Hydroxy-2-methyl-1-(4-tolyl)-4-pyridone

Sa？etak A method for the extraction and spectrophotometric determination of iridium(IV) with 3-hydroxy-2-methyl-1-phenyl-4-pyridone (HX) or 3-hydroxy-2-methyl-1-(4-tolyl)-4-pyridone (HY) is described. The IrIV-HX(HY) complex was extracted from sulphuric or hydrochloric acid solutions into chloroform, dichloromethane, isobutyl methyl ketone or isoamyl alcohol. Absorbance was measured at 365 nm. The complex system conformed to Beer's law over the range of 1.9–38.5 mg cm-3 of iridium(IV). The relative standard deviations estimated from six independent determinations in samples of 3.84 and 15.36 mg cm-3 of iridium(IV) were 2 and 1.44 %, respectively. A derivative spectrophotometric method, based on digitized second-derivative absorption spectra, has been developed for the determination of microgram amounts of iridium(IV) with HX dissolved in chloroform in the presence of palladium(II). Iridium (1.9–34 μg cm-3) was determined in the presence of palladium (1–8 μg cm-3) with good precision and accuracy. The method was applied for the analyte determination in synthetic mixtures