The effects of the cationic (tetrabutyl ammonium chloride, TBC), anionic (sodium dodecyl sulfate, SDS) and nonionic (TRITON X-100) surfactants on the potentiometric properties of zinc- and cadmium-selective electrodes (ISEs) were investigated. The studies were carried out with plasticized PVC membranes doped with several new acidic chelating ionophores. The electrode basic analytical parameters, such as measurement range, slope characteristics, detection limit, response time and selectivity coefficients in relation to some inorganic cations in the presence and absence of surfactants, were investigated. As follows from the studies, the presence of surfactants in the sample is responsible first of all for the increase in response time and in detection limit, and a decrease in the characteristic slope as well as reduction of electrode selectivity. (c) 2005 Elsevier Ltd. All rights reserved.