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

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 * To whom correspondence should be addressed. 93 Downloaded by [University of Connecticut] at 04:45 16 September 2013 94 TORAL ET AL.perchloric acid solution, upon heating at 90° C for 30 min and on the subsequent direct derivative spectrophotometric measurement. The zerocrossing 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 8.9xlO" 7 -3.1x10" M for platinum and 4.6xlO" 7 -6.8xlO" 5 M, for palladium. The detection limits achieved (3a) were found to be 2.7xlO' 7 M of platinum and 1.4xlO' 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.

Determination of Pd(II) content in catalysts and tap water samples via photoacoustic spectroscopy analysis of Pd(II)-3-[2′2′-thiazolylazo]-2,6-diaminopyridine complex on solid phase

“…3. The PA spectrum of the 2,6-TADAP-resin shows two absorption bands localized in the ranges 400-445 nm (band 1) and 460-600 nm (band 2) in agreement with previously published photometric bands assignments of the ligand adsorbed on the resin [25,27,28]. No other pronounced peaks are observed in the blank spectrum.…”

“…In this work, potential interference compounds were selected based on the studied matrix composition and added reagents. The interference studies on the determination of Pd(II) were made in a similar procedure previously described [27]. Briefly, known quantities of a foreign ion were added to the solution containing 60 g L −1 of Pd(II).…”

Spectrophotometric Determination of Traces of Platinum with 5-Chloro-2-hydroxythiobenzhydrazide after Extraction into Molten Naphthalene

“…These methods suffer from some drawbacks, such as a longer waiting period for color development, 7,9 a need for multiple extractions for quantitative recovery of the metal, 8 presence of stannous chloride, 12,14 narrow pH range, 10,13,19 high molarity of aqueous phase, 14,16 low absorptivity, 15 low sensitivity 13,20 and low stability of the reagents, [7][8][9] as shown in Table 1. None of these methods allow the separation and separate determination of platinum and rhenium.…”

“…6 The use of thiohydrazides such as o-hydroxythiobenzhydrazide, 7 thiobenzhydrazide, 8 α-naphthalenethiocarboxhydrazide, 2-pyrrolthiocarboxhydrazide, furanthiocarboxhydrazide, thiophenethiocarboxhydrazide, 9 dibenzylidenethiocarbohydrazide, 10 and 2-furancarbothioic acid hydrazide 11 in the spectrophotometric determination of rhenium and platinum group metals has been described in a number of papers. Other reagents such as dithizone, 12 anisaldehyde-4-phenyl-3-thiosemicarbazone, 13 dithizone-polyurathane, 14 4-phenylthiosemicarbazide, 15 3-(2′-thiazolylazo)-2,6-diaminopyridine, 16 N-(m-methylphenyl)-N′-(sodium p-aminobenzenesulfonate)-thiourea, 17 piperonal thiosemicarbazone, 18 and leuco xylene cyanol FF, 19 have been reported for spectrophotometric determination of platinum after liquid-liquid extraction. The reagents phenanthrenequinone monoximes 20,21 and 1-(2-pyridylazo)-2-naphthol 22 have been used for spectrophotometric determination of platinum after solid-liquid extraction.…”

Synthesis and Spectral Studies of Some Transition metal Complexes

“…These ligand systems have gained considerable importance because of their utility as model compounds in bioinorganic studies as well as their potential as catalysts in many reactions 9 . They find application in the determination of transition metal ions [10][11][12][13] in the study of acid base equilibrium acidity constants value 13 & for analytical purposes 15 .…”