In this study, cellulose triacetate was used as a suitable base polymer for polymer-blended membranes for ion sensing and separation. Polymer-blended membranes were prepared with the solvent casting technique in the presence of mixed plasticizer and a metal ion carrier known as an ionophore. 7-Dodecenyl-8-hydroxyquinoline and N,N'-diphenylethyl Kemp's triacid diamide, in addition to the newly synthesized 8-[N-acetyl-O-(4-tert-butyl benzyl)-L-tyrosylamino] quinoline, were used as representative examples for ionophores. The membranes were evaluated through the transport of copper and lead ions into 0.1M nitric acid as the receiving phase. The concentrations of the investigated metal ions in both phases were assayed by atomic absorption spectrometry. From this study, it can be concluded that the efficiency of the membrane, either as an ion-transporting or as an ion-extracting condidate, is controlled by the amount of the immobilized ionophore, the immobilization time within the membrane matrix while in contact with the receiving phase, the nature of the ionophore-metal ion complex, and so on. The carrier-mediated transport mechanism was also investigated.