title: Solute-solvent interactions in micellar electrokinetic chromatography. 6. Optimization of the selectivity of lithium dodecyl sulfate-lithium perfluorooctanesulfonate mixed micellar buffers.
abstract: The optimization of the composition of mixed surfactants used as micellar electrokinetic chromatography (MEKC) pseudostationary phases is proposed as an effective method for the separation of complex mixtures of analytes. The solvation parameter model is used to select two surfactants (lithium dodecyl sulfate, LDS, and lithium perfluorooctanesulfonate, LPFOS) with contrasting solvation properties. Combination of these two surfactants allows variations of the solvation properties of MEKC pseudostationary phase along a wide range. Thus, the convenient variation of the proportion of both surfactants allows an effective control of the selectivity in such systems. An algorithm that predicts the overall resolution of a given mixture of compounds is described and applied to optimize the composition of the mixed surfactant for the separation of the mixture. The algorithm is based on the calculation of peak purities on simulated chromatograms as a function of the composition of the mixed LDS/LPFOS micellar buffer from data at several micellar buffer compositions. Successful separations were achieved for mixtures containing up to 20 compounds, in less than 12 min.
authors.affiliation: Departament de Química Analítica, Universitat de Barcelona, Spain.
authors.forename: Elisabet
authors.initials: E
authors.lastname: Fuguet
authors.forename: Clara
authors.initials: C
authors.lastname: Ràfols
authors.forename: José Ramón
authors.initials: JR
authors.lastname: Torres-Lapasió
authors.forename: María Celia
authors.initials: MC
authors.lastname: García-Alvarez-Coque
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Bosch
authors.forename: Martí
authors.initials: M
authors.lastname: Rosés
mesh_terms: D002021:Buffers; D002210:Caprylates / Q000592:standards; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods / Q000592:standards*; D005466:Fluorocarbons / Q000592:standards; D008823:Micelles; D009930:Organic Chemicals / Q000302:isolation & purification; D012967:Sodium Dodecyl Sulfate / Q000592:standards; D012997:Solvents / Q000592:standards; D013501:Surface-Active Agents / Q000592:standards*
chemical_list: D002021:Buffers; D002210:Caprylates; D005466:Fluorocarbons; D008823:Micelles; D009930:Organic Chemicals; D012997:Solvents; D013501:Surface-Active Agents; D012967:Sodium Dodecyl Sulfate; C023036:perfluorooctanoic acid; C028913:dodecyl sulfate