Simultaneous Determination of Platinum and Palladium by Second Derivative Spectrophotometry Using 3-(2'-Thiazolylazo)-2, 6-Diaminopyridine as Chromophore Ligand

Abstract

ABSTRACT A second derivative spectrophotometric method has been developed for the determination of palladium and platinum in mixtures. The method is based on the formation of the platinum and palladium complexes with 3-(2-thiazolylazo)-2, 6-diaminopyridine, (2, 6-TADAP), in the presence of 1.7 M perchloric acid solution, upon heating at 90° C for 30 min and on the subsequent direct derivative spectrophotometric measurement. The zero-crossing approach and the graphic method were used for determination of platinum and palladium, respectively. Each analyte was determinated in the presence of one another in the ranges 8.9×10-7 -3.1×10-5 M for platinum and 4.6×10-7 - 6.8×10-5 M, for palladium. The detection limits achieved (3a) were found to be 2.7×10-7 M of platinum and 1.4×10-7 M of palladium. The relative standard deviations were in all instances less than 1.0%. In this work is included a study of effect of interferents and the application of the proposed method in synthetic mixtures.