Silver Ion-Selective Polymeric Membrane Electrode Based on Lipophilic Monothiacrown Ether

Abstract

Dodecyl-monothia-16-crown-5, which contains one sulfur and four oxygen atoms, was synthesized and tested for its usefulness as a neutral carrier for Ag⁺-selective polymeric membrane electrodes. Employment of a Ag⁺-complex of the thiacrown ether as the membrane active material instead of the thiacrown ether itself allowed the better potential response. The resulted ion selective electrodes exhibited Nernstian response to Ag⁺ in a wide activity range. The ion selectivities against alkali, alkaline-earth, and heavy metal ions, NH₄⁺, and H⁺ were quite excellent. Silver ion in artificial samples was successfully determined by Ag⁺ potentiometric titration and Gran′s plot method with the Ag⁺ electrode.