Comparative study of the determination of platinum by extraction with Cyanex 923 and Cyanex 471X from bromide media

The extraction equilibrium study of Pt(IV) was carried out with Cyanex 923 and Cyanex 471X in toluene from hydrobromic acid media to investigate their extraction capacity, since they have different donor atoms, 'O' and 'S'. T heir distribution equilibria were studied as a function of extractant conce ntration, diluents, hydrobromic acid concentration and the effect of temper ature on extraction. Pt(IV) was quantitatively extracted with 0.1 mol dm(-3 ) Cyanex 923 in toluene from 5.0-8.0 mol dm(-3) HBr media and was stripped with 4.0 mol dm(-3) perchloric acid. However it was also quantitatively ext racted with 0.1 mol dm(-3) Cyanex471X (with 0.1 mol dm(-3) SnCl2) in toluen e from 6.0-8.0 mol dm(-3) HBr media and was stripped with 1.0 mol dm(-3) st abilized sodium thiosulfate solution at pH 9.0. The slope analysis method i ndicated metal complex species of 1:1 for Pt(IV) with Cyanex 923 and Cyanex 471X in toluene from HBr media. These methods were successfully applied to the analysis of platinum in real samples. (C) 2001 Society of Chemical Ind ustry.