AC‐voltammetric determination of the total concentration of nonionic and anionic surfactants in aqueous systems

Abstract

AbstractThe tensammetric determination of the total concentration of mixtures of nonionic and anionic surfactants is desribed. By taking advantage of the different accumulation behavior of nonionic and anionic surfactants on the surface of the hanging mercury drop electrode (HMDE), it has been possible to determine the total concentration of nonionic surfactants without contribution from anionic surfactants. After subtraction of nonionic surfactant concentration from total, the concentration of anionic surfactants can be determined indirectly. Detection limits of 10 to 100 μg L−1 for single compounds and 100 μg L−1 for mixtures were calculated. Humic acids, relevant complexing reagents (like EDTA) and different cations do not interfere in the determination when they are present in typical concentrations found in surface waters. The method has been applied to several mixtures of surfactants. The possibility of solid‐phase‐extraction (SPE) for sample pretreatment has been investigated.