Highly efficient and selective membrane transport of silver(I) ion by a cooperative carrier composed of aza-18-crown-6 and palmitic acid

A given mixture of aza-18-crown-6 and plamitic acid was found to be an excellent cooperative carrier for the efficient transport of Ag+ ions through a bulk liquid membrane. In the presence S2O32- ion, as a suitable metal ion acceptor in the receiving phase, the amount of silver transported across the liquid membrane after 90 min was 93.6+/-1.5%. The selectivity and efficiency of silver transport from aqueous solutions containing other cations such as Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Pb2+, and Fe2+ ions were investigated. In the presence of diphosphate as a suitable masking agent in the source phase, the interfering effect of Cd2+ ion was eliminated.