Adsorption Behavior Of Metal Ions Research Articles

8-Quinolinol-5-sulfonic acid-loaded resin as a preconcentrating agent in the neutron activation analysis of the chalcophile elements (author's transl)

A chelating agent-loaded resin consisting of 8-quinolinol-5-sulfonic acid and an anion-exchange resin (HOx-resin) was prepared in order to concentrate trace chalcophile elements in natural water samples selectively before neutron activation analysis. The exchange capacity of the Diaion SA No. 100 for the reagent (1.8 meq . g-1 resin) corresponds approximately to that for chloride ion (1.83 meq . g-1 resin), indicating that 8-quinolinol-5-sulfonic acid is adsorbed quantitatively on the exchange site of the resin through the sulfonate anion in the reagent. The basic conditions for the adsorption of the metal ions on the resin were investigated by employing the column method. The nitrate concentration and the pH of the sample solution affect the adsorption behavior of metal ions. Several solutions containing metal ions with varying pH or varying nitrate concentration were applied to the resin column (35 mm x 7 mm phi) with a flow rate of 2.0 cm3 . min-1. As a result, the optimum conditions for the quantitative adsorption of copper(II), zinc(II), cadmium(II), cobalt(II), nickel(II) and manganese(II) were as follows: NO3- less than 0.01 mol . dm-3 pH greater than 4.6. Furthermore, the feasibility of the above conditions as well as quantitative adsorption of the chalcophile elements was confirmed through the neutron activation analysis of the synthesized metal solutions.

Adsorption of the Silver-Thiourea Complex in Montmorillonite

The influence of uncharged ligands on the adsorption behaviour of metal ions in ion exchangers has received little attention, the limited number of studies being concerned mostly with the formation of metal-amine complexes in resins1. For mineral ion exchangers, even fewer quantitative data are available regarding the nature of these phenomena. Helfferich2 anticipated that the effect of non-ionic ligands on complex ion adsorption should be quite small because the effective charge of the ion is unaltered and ligand molecules merely replace solvent molecules from the solvation shell. The use of uncharged ligands for enhancing the sensitivity of electro-analytical determinations3 and some recent data concerning the synergistic effect of amines on the adsorption of transition metal ions in resins4 do, however, indicate the existence of important interactions.