Highly selective and efficient membrane transport of palladium as PdCl42- ion using NH4+-dibenzyldiaza-18-crown-6 as carrier

Ammonium-dibenzyldiaza-18-crown-6 complex was used as a highly efficient ca rrier for the uphill transport of palladium as PdCl42- complex ion through a chloroform bulk liquid membrane. By using thiocyanate as a metal ion acce ptor in the receiving phase, the amount of palladium transported across the liquid membrane after 120 min was 92.2+/-1.4%. The selectivity and efficie ncy of palladium transport from aqueous solutions containing Tl+, Ca2+ Mn2, Co2+, Ni2+, Cu2+, Zn2+, Pb2+, Cd2+, Hg2+, Fe3+ and Cr3+ were investigated . In the presence of EDTA at pH 4.7 as a suitable masking agent in the sour ce phase, the interfering effect of Hg2+ ion was diminished drastically. (C ) 1999 Elsevier Science B.V. All rights reserved.