Properties of chelating sorbents prepared by impregnation of LiChroprep RP-8 and LiChroprep RP-18 with ion pairs formed by Aliquat 336 and Nitroso-R-Salt

Two new chelating sorbents for metal ions were prepared by the impregnation of chemically modified silicas LiChroprep RP-8 and RP-18 with ion pairs co mposed of the cation of Aliquat 336 and the anion of Nitroso-R-Salt. The so rbents were compared with analogous sorbents with a plain silica carrier co ntaining the same ion pairs. A hypothetical molecular mechanism of binding this ion pair by the surfaces of the applied carriers is presented. A highe r stability of the two sorbents in comparison with that of the plain silica chelating sorbent was demonstrated. The sorbents obtained were applied to chromatographic separations of some chosen mixtures of some metal ions (the recovery of the separated metals was in the range 97% Co2+-99.5% Ca2+) and for additional purification of aqueous solutions of alkali and alkaline ea rth metals from trace amounts of heavy metals (Zn, Cd, Pb and Cu). The effe ctiveness of purification was confirmed by anodic stripping voltammetry. Th e multiple use of the sorbents based on RP-8 and RP-18 in sorption-desorpti on processes of metal ions without deterioration of their sorption capaciti es was demonstrated.