Anion-exchange behaviour of some elements on a weakly basic anion exchanger in hydrobromic acid medium The adsorbability of several elements has been studied in the system weakly basic anion exchange resin Amberlite IRA-68 (Br −HBr + Br 2. Distribution coefficients of more than 30 elements were determined by batch equilibration in the HBr concentration range 0.01–12 M. In most instances the distribution coefficients increase with increase in acid concentration. Some elements, such as Cu, Co, Fe, Mn, In, Ga and U, are adsorbed only at acid concentrations greater than 4 M. Pt, Hg, Ag and, to a somewhat smaller extent, Au, Tl and Re, show high distribution coefficients in dilute HBr solution. In general, the adsorbabilities of elements on Amberlite IRA-68 in the bromide system are lower than the adsorbabilities in an analogous system with strongly basic Dowex 1 resin. The observed differences in distribution coefficients are high enough for some interesting separations to be obtained. The possibility of column separations of several mixtures, such as EuU, ZnCdHG and CuAgAu, was demonstrated. The influence of temperature on the separation of the latter mixture was studied and the most important chromatographic parameters (distribution coefficients, separation factors, resolutions and plate heights) were calculated.