The transfer of the tetraethylammonium (TEA) cations across the interface between an aqueous phase and an organic phase of 1,2-dichloroethane, with a layer of dipalmitoyl phosphaticlic acid (DPPA) adsorbed at the interface, was studied by cyclic voltammetry. It has been shown that the passage of the TEA(+) cations into the organic phase is permitted by ion exchange of the TEA(+) cations for protons contained in the DPPA molecules, followed by re-exchange permitting the release of the TEA(+) cations into the organic phase. The principal steps of the reaction mechanism are the transport of the TEA(+) cations through the layers of adsorbed DPPA and the slow re-exchange in the adsorbed layer. The cyclic voltammetry experiments permit semiquantitative estimation of the appropriate kinetic and thermodynamic constants describing the process. (C) 2009 Elsevier B.V. All rights reserved.