Influence of pH and pKa values on electrophoretic behaviour of quinolones in aqueous and hydro-organic media.
Through correct pH measurements, pKa and activity coefficient values, a model describing their effect on electrophoretic behaviour of substances is established. The suggested model uses the pH values in the acetonitrile-water mixtures used and takes into account the effect of activity coefficients. The model permits the calculation of acidity constants of analytes in hydro-organic media and also the prediction of the effect of pH on the electrophoretic mobility. The model is tested by determining the dissociation constants of a series of nine quinolones in acetonitrile-water mixtures of 0, 5.5, 10 and 30% (w/w) acetonitrile.
Barrón
D
D
Department of Analytical Chemistry, Universitat de Barcelona, Spain.
Jiménez-Lozano
E
E
Irles
A
A
Barbosa
J
J
D042462:4-Quinolones; D000890:Anti-Infective Agents / Q000737:chemistry / Q000302:isolation & purification*; D019075:Electrophoresis, Capillary / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D009930:Organic Chemicals; D009994:Osmolar Concentration; D014867:Water
D042462:4-Quinolones; D000890:Anti-Infective Agents; D009930:Organic Chemicals; D014867:Water