title: Generalization of ionic partition diagrams to lipophilic compounds and to biphasic systems with variable phase volume ratios.
abstract: The ionic partition diagram methodology has been generalized to address both hydrophilic and lipophilic compounds and to consider biphasic systems with variable phase volume ratios. With this generalized approach electrochemical measurements of ion transfer potentials afford the determination of the standard partition coefficients of all forms of ionizable molecules, including the neutral form, as well as the evaluation of the dissociation constant of monoprotic substances. An interesting consequence of this approach is the definition of an extraction pK(a,ext) which is the apparent pK(a) of neutral acids and bases when dissolved in the organic phase.
authors.affiliation: Laboratoire d'électrochimie, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
authors.forename: V
authors.initials: V
authors.lastname: Gobry
authors.forename: S
authors.initials: S
authors.lastname: Ulmeanu
authors.forename: F
authors.initials: F
authors.lastname: Reymond
authors.forename: G
authors.initials: G
authors.lastname: Bouchard
authors.forename: P A
authors.initials: PA
authors.lastname: Carrupt
authors.forename: B
authors.initials: B
authors.lastname: Testa
authors.forename: H H
authors.initials: HH
authors.lastname: Girault
mesh_terms: D019297:2,4-Dinitrophenol / Q000737:chemistry; D000143:Acids / Q000737:chemistry; D000814:Aniline Compounds / Q000737:chemistry; D004563:Electrochemistry; D006863:Hydrogen-Ion Concentration; D007477:Ions / Q000737:chemistry; D007700:Kinetics; D008055:Lipids / Q000737:chemistry*; D012995:Solubility; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D000143:Acids; D000814:Aniline Compounds; D007477:Ions; D008055:Lipids; D014867:Water; D019297:2,4-Dinitrophenol