title: Micellar electrokinetic chromatography systems for the separation of mixtures of charged and uncharged compounds.
abstract: In this study, the migration behavior of charged and uncharged analytes was investigated under different conditions. Effective mobilities - electrophoretic mobilities under the influence of micelles - of cations, anions, and neutrals were measured at neutral, basic, and acidic pH (7.5, 11, and 2.2) using background electrolytes containing different sodium dodecyl sulfate (SDS) concentrations (0-90 mM) and acetonitrile (ACN) proportions (0-75%). SDS concentration and ACN proportion were found to have a tremendous effect on the effective mobilities and migration order of the model compounds. Although the SDS micelles preferably interact with neutrals and cations, hydrophobic bonds can also occur with anions. Cations, anions, and neutrals having rather different migration behaviors, it is possible to considerably enhance the selectivity of the method by adjusting properly the SDS concentration and the ACN proportion. These observations confirm the interest of using micellar electrokinetic chromatography not only for the separation of neutral substances but also to analyze charged compounds.
authors.affiliation: Laboratory of Analytical Pharmaceutical Chemistry, Department of Pharmacy, CIRM, University of Liège, Belgium.
authors.forename: Caroline
authors.initials: C
authors.lastname: Lamalle
authors.forename: Anne-Catherine
authors.initials: AC
authors.lastname: Servais
authors.forename: Ines
authors.initials: I
authors.lastname: Fradi
authors.forename: Jacques
authors.initials: J
authors.lastname: Crommen
authors.forename: Marianne
authors.initials: M
authors.lastname: Fillet
mesh_terms: D000838:Anions / Q000737:chemistry; D002412:Cations / Q000737:chemistry; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000295:instrumentation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D009930:Organic Chemicals / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D000838:Anions; D002412:Cations; D009930:Organic Chemicals