title: Separation of cationic analytes by nonionic micellar electrokinetic chromatography using polyoxyethylene lauryl ether surfactants with different polyoxyethylene length.
abstract: Although nonionic micellar electrokinetic chromatography is used for the separation of charged compounds that are not easily separated by capillary zone electrophoresis, the effect of the hydrophilic moiety of the nonionic surfactant has not been studied well. In this study, the separation of ultraviolet-absorbing amino acids was studied in electrokinetic chromatography using neutral polyoxyethylene lauryl ether surfactants (Adekatol) in the separation solution. The effect of the polyethylene moiety (the number of repeating units was from 6.5 to 50) of the hydrophobic test amino acids (methionine, tryptophan, and tysorine) was studied using a 10 cm effective length capillary. The separation mechanism was based on hydrophobic as well as hydrogen bonding interactions at the micellar surface, which was made of the polyoxyethylene moiety. The length of the polyoxyethylene moiety of the surfactants was not important in nonionic micellar electrokinetic chromatography mode.
authors.affiliation: GPLLI Program, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan; Australian Centre for Research on Separation Science (ACROSS), School of Chemistry, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Joselito P
authors.initials: JP
authors.lastname: Quirino
authors.forename: Masaru
authors.initials: M
authors.lastname: Kato
mesh_terms: D000596:Amino Acids / Q000737:chemistry / Q000302:isolation & purification*; D002412:Cations / Q000302:isolation & purification; D020374:Chromatography, Micellar Electrokinetic Capillary; D057927:Hydrophobic and Hydrophilic Interactions; D015394:Molecular Structure; D011092:Polyethylene Glycols / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D002412:Cations; C495681:Sanonic SS-90; D013501:Surface-Active Agents; D011092:Polyethylene Glycols
keywords: Cationic analytes; Micellar electrokinetic chromatography; Nonionic surfactants