Selective and efficient liquid membrane transport of thallium (III) ion by potassium-dicyclohexyl-18-crown-6 as specific carrier

Abstract

Potassium-dicyclohexyl-18-crown-6 was used as a selective and efficient carrier for the uphill transport of thallium (III) ion as [TlCl4]- complex ion through a chloroform bulk liquid membrane. By using oxalate anion as a metal ion acceptor in the receiving phase, the amount of thallium (III) transported across the liquid membrane after 120min was 962%. The selectivity and efficiencies of thallium transport from aqueous solutions containing Cu2+, Zn2+, Ni2+, Cd2+, Pb2+, Co3+, Mn2+, Cr3+, Mg2+, Ca2+, K+, Na+, and Fe3+ ions were investigated. In the presence of Na3PO4 (0.01M) at pH=3 as a suitable precipitation agent in the source phase, the interfering effect of Pb2+ ion were diminished drastically.