title: Solute-solvent interactions in micellar electrokinetic chromatography: V. Factors that produce peak splitting.
abstract: The experimental conditions that produce analyte peak splitting in micellar electrokinetic capillary chromatography (MEKC) have been systematically investigated. The system studied was a neutral phosphate buffer and sodium dodecyl sulfate (SDS) micelles as pseudostationary phase. A number of analytes showing a wide variety of hydrophobicity values and several organic solvents as sample diluents have been tested. Peak splitting phenomena are mainly due to the presence of organic solvent in the sample solution. They increase with the hydrophobicity of the analyte and decrease with the increase of the surfactant concentration. When hydrophobic compounds are analyzed the suggested ways to avoid split peaks are: (i) the use of 1-propanol or 1-butanol as sample diluent instead of methanol or acetonitrile or (ii) the use of high concentration of surfactant in the separating solution when the analyte must be dissolved in pure methanol or acetonitrile.
authors.affiliation: Departament de Química Analítica, Universitat de Barcelona, Barcelona, Spain.
authors.forename: Clara
authors.initials: C
authors.lastname: Ràfols
authors.forename: Ana
authors.initials: A
authors.lastname: Poza
authors.forename: Elisabet
authors.initials: E
authors.lastname: Fuguet
authors.forename: Martí
authors.initials: M
authors.lastname: Rosés
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Bosch
mesh_terms: D000438:Alcohols; D002021:Buffers; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods* / Q000706:statistics & numerical data; D000432:Methanol; D008823:Micelles; D009281:Naphthalenes / Q000032:analysis; D010710:Phosphates; D012967:Sodium Dodecyl Sulfate; D012996:Solutions; D012997:Solvents; D013501:Surface-Active Agents
chemical_list: D000438:Alcohols; D002021:Buffers; D008823:Micelles; D009281:Naphthalenes; D010710:Phosphates; D012996:Solutions; D012997:Solvents; D013501:Surface-Active Agents; C031721:naphthalene; D012967:Sodium Dodecyl Sulfate; D000432:Methanol