Specific uphill transport of Cd2+ ion by a cooperative carrier composed of aza-18-crown-6 and palmitic acid

A given mixture of aza-18-crown-6 and palmitic acid was found to be an excellent cooperative carrier for the specific uphill transport of cadmium ions through a chloroform membrane. In the presence of thiosulfate ion as a suitable metal ion acceptor in the receiving phase, the amount of Cd2+ ion transported across the liquid membrane after 80 min is 93.9 +/- 1.0%. The selectivity and efficiency of cadmium transport from aqueous solutions containing other cations such as Fe3+, Co2+, Ni2+ Cu2+, Zn2+, Pb2+, Ag+ as well as alkali and alkaline earth cations were investigated. In the presence of thiocyanate, as a proper masking agent in the source phase, the interfering effects of Cu2+ and Ag+ ions were successfully eliminated.