Lam HT Pereira CM Roussel C Carrupt PA Girault HH 2006 An experimental setup to study the pH dependence of standard ion-transfer potentials at the water/NPOE interface is presented. The system is composed of a microhole generated by laser photoablation in a 12-microm polyethylene terephthalate film, the aqueous phase consisting of a commercial immobilized pH gradient gel reswelled in electrolyte solution and a droplet of organic solution. Two electrodes are used, an Ag/AgCl aqueous electrode and an Ag/AgTPBCl organic electrode. This setup is applied to the study of two ionizable compounds (pyridine, 2,4-dinitrophenol). Thermodynamic parameters such as the standard transfer potential, the Gibbs energy of transfer, and the partition coefficients of the ionized forms as well as the neutral forms of these drug compounds are evaluated by differential pulse voltammetry. The data obtained are summarized in ionic partition diagrams, which are a useful tool for predicting and interpreting the transfer behavior of ionized drugs at the liquid/liquid interfaces mimicking the biological membranes. application/pdf https://sonar.ch/global/documents/96725 eng info:eu-repo/semantics/altIdentifier/doi/10.1021/ac051808a info:eu-repo/semantics/altIdentifier/pmid/16503600 info:eu-repo/semantics/openAccess Analytical chemistry. - 2006 2,4-Dinitrophenol Cell Membrane Permeability Electrochemistry Electrodes Gels Hydrogen-Ion Concentration Ions Membrane Potentials Models, Biological Models, Chemical Pharmaceutical Preparations Pharmacokinetics Pyridines Thermodynamics Immobilized pH gradient gel cell to study the pH dependence of drug lipophilicity. http://purl.org/coar/resource_type/c_6501