Assessment of ion-ionophore complex diffusion coefficients in solvent polymeric membranes

Abstract

Chronoamperometric (CA) and chronopotentiometric (CP) transients have been used previously for the determination of the diffusion coefficients of free ionophores in ion-selective liquid membranes. In this work, the CA and CP transients are utilized to determine the diffusion coefficients of a variety of ion-ionophore complexes in these membranes. The conditions under which the ion-ionophore complex diffusion coefficients can be determined from the CA and CP transients are discussed. For most ionophores, the ion-ionophore complex diffusion coefficients were found to be slightly smaller or similar to the previously calculated free ionophore diffusion coefficients. However, for a couple of ionophores, the ion-ionophore complex diffusion coefficients were found to be significantly smaller than expected. Significant ion-pair formation in the membranes can explain this disparity. © 2009 WILEY-VCH Verlag GmbH&Co.

Publication Title

Electroanalysis

Link to Full Text

Share

COinS