Ion exchange studies of arsenazo-III and thorium(IV) from aqueous solutions of arsenazo-III with AG-2 x 8, dowex-50 w x 8 and chelex-100

The sorption behaviour of Th(IV) from intermediate acidic solutions (0.5-1.5 N HCl) of arsenazo-III with three different types of ion exchangers, namely dowex-50 w x 8, AG-2 X 8 and chelex-100 is studied at different concentrations of arsenazo-III corresponding to metal: reagent ratio of 1:1 to 1:3. The sorption behaviour of arsenazo-III with AG-2 X 8 and chelex-100 under various experimental conditions is studied as well. Complete sorption of the reagent on AG-2 X 8 under all studied conditions is found. The sorption process from solutions at high PH-values is found to be relatively slow. complete sorption of reagent on chelex-100 is found from acidic solutions. The percent uptake decreases sharply with increasing PH value. While partial sorption of Th(IV) or Th(IV)-arsenazo-III complexes on dowex-50 W X 8 or AG-2 X 8, respectively, is found, chelex-100 is found to be selective for concentrating thorium as coloured arsenazo-III complex which may be useful in ion exchange phase absorptiometry. The sorbed complex from 0.5 N HCl solutions of arsenazo-III is proved to be Th L. 6 figs., 1 tab