Simultaneous determination of platinum and palladium by second derivative spectrophotometry using 3-(2 '-thiazolylazo)-2,6-diaminopyridine as chromophore ligand

A second derivative spectrophotometric method has been developed for the de termination of palladium and platinum in mixtures. The method is based on t he 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 aci d solution, upon heating at 90 degrees C for 30 min and on the subsequent d irect derivative spectrophotometric measurement. The zero-crossing approach and the graphic method were used far determination of platinum and palladi um, respectively. Each analyte was determinated in the presence of one anot her in the ranges 8.9x10(-7) - 3.1x10(-5) M for platinum and 4.6x10(-7) - 6 .8x10(-5) M, for palladium. The detection limits achieved (3 sigma) were fo und to be 2.7x10(-7) M of platinum and 1.4x10(-7) M of palladium. The relat ive 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 pr oposed method in synthetic mixtures.