Determination of ionic surfactants by flow injection pseudotitration

Abstract

Two flow-through surfactant-selective electrodes have been developed which are selective for anionic and cationic surfactant ions. They employ PVC membranes containing appropriate ion-exchanging salts, coated on the internal wall of a graphite tube. The performance of the electrodes as sensors in a flow injection pseudotitration has been evaluated. By relating peak width to the logarithm of the concentration of a series of standard surfactants, a linear calibration graph may be produced. This permits the determination of unknowns by extrapolation. The system is of particular value when applied to the control analysis of known standards.