A chelate sorbent prepared by the modification of silica gel with acid Orange 8 and its application

Silica gel impregnated with a mixture of Aliquat 336 and acid Orange 8 was used as a chelating sorbent for 14 metal ions: Na, K, Mg, Ca, Al, Zn, Cu, C d, Fe(III), Mn, Ph, Cr(III), Co and Ni. The relative capacities of the sorb ent toward the metal ions were determined in the pH range 1-9, as well as t he concentrations of HCl and HClO4 required for elution of the retained met als. All the retained metals could be eluted with dilute solutions of HClO4 without elution of the chelating agent from the sorbent. The sorbent was u sed for preconcentration of trace amounts of some metals from aqueous solut ions before their determination by AAS, for the separation of metal ion mix tures by column-extraction chromatography and for additional purification o f some salt solutions from trace amounts of Zn, Cd, Ph and Cu. The effectiv eness of purification was confirmed by anodic stripping voltammetry.