Development of ion-selective electrodes for use in the titration of ionic surfactants in mixed solvent systems

Abstract

By depositing PVC membranes containing surfactant ion pairs as ion exchangers on a graphite support, ion-selective electrodes have been constructed that are responsive to ionic surfactants at concentrations between 10^–2 and 10^–6M. The operating characteristics of the electrodes have been evaluated, particularly with respect to their use in mixed solvent systems. Successful quantification of alkyl sulphates, alkylbenzenesulphonates and quaternary salts has been achieved by ion-pair titration. The electrodes have also been applied successfully in the analysis of commercially formulated detergent products after their surface-active components had been recovered and fractionated.