ja962187t_si_001.pdf (502.35 kB)
Ionic Partition Diagrams: A Potential−pH Representation
journal contribution
posted on 1996-11-27, 00:00 authored by Frédéric Reymond, Guillaume Steyaert, Pierre-Alain Carrupt, Bernard Testa, Hubert GiraultA general method to predict and interpret the transfer mechanisms
of ionizable compounds at the interface
between two immiscible electrolyte solutions (ITIES) is presented.
The approach is based on the construction of the
ionic partition diagram of the solute. It consists in defining
equiconcentration boundaries as a function of the Galvani
potential difference and aqueous pH by taking into account the
thermodynamic equilibria governing the distribution
of the various acid/base forms of the molecules involved. The
method defines the domains of predominance of each
species either in the aqueous or in the organic phase. The
application of ionic partition diagrams to quinidine
offers
a global and direct visualization of all the species and demonstrates
the validity and efficiency of the method in
helping to understand the transfer and partition mechanisms of
ionizable drugs.