Separation of Platinum(IV) from Pharmaceuticals using P-Methylphenyl Thiourea by Solvent Extraction: Separation from Palladium(II), Nickel (II)

Abstract

A method for the solvent extraction spectrophotometric method has been developed for determination of microgram amount of platinum(IV) using para-methylphenyl thiourea (PMPT) as a chromogenic reagent is developed. The basis of proposed protocol is pink colored Pt(IV)-PMPT complex was formed in 0.03 mol dm−3 potassium iodate media at room temperature and shows maximum absorption at 506nm. The colored complex obeys Beer’s law up to 5.0 μg cm−3 for platinum. The molar absorptivity and sandell’s sensitivity were found to be 6.78 x 103 dm3 mol−1 cm−1 and 0.029 μg cm−1. Stability of platinum(IV)-PMPT complex was >48 hours. Various experimental parameters for the extraction and determination of platinum(IV) have been checked and optimal conditions are developed. The developed method is selective for determination of platinum(IV) in presence of large number of interfering ions The method finds applications viz. the determination of platinum(IV) from pharmaceutical sample, synthetic mixtures corresponding to alloys, binary and ternary mixtures. The method also permits the sequential separation of palladium(II), platinum(IV) and nickel(II).