title: Enhanced stability self-assembled coatings for protein separations by capillary zone electrophoresis through the use of long-chained surfactants.
abstract: Semipermanent coatings were generated within fused-silica capillaries by flushing the capillary with a 0.1 mM solution of the double-chained cationic surfactants didodecyldimethylammonium bromide, dimethylditetradecylammonium bromide (2C(14)DAB), dihexadecyldimethylammonium bromide, and dimethyldioctadecylammonium bromide (2C(18)DAB) and the triple-chained surfactant tridodecylmethylammonium iodide. All of these coatings were semipermanent, whereby the coating remained intact after the unadsorbed surfactant was removed from the capillary. The separation efficiencies for four model cationic proteins ranged from 1.2 to 1.4 million plates/m for the 2C(14)DAB coating to 0.3-0.4 million plates/m for the 2C(18)DAB coatings. The stability of the coating increased with increasing hydrophobicity of the surfactant (i.e., increasing chain length and decreasing cmc). Over 60 successive separations were performed on a 2C(18)DAB-coated capillary over 12 days, without any regeneration of the coating. The migration times varied by less than 2.3% over this period with no loss in efficiency.
authors.affiliation: Department of Chemistry, University of Alberta, Gunning/Lemieux Chemistry Centre, Edmonton, Alberta, Canada T6G 2G2.
authors.forename: Mahmoud M
authors.initials: MM
authors.lastname: Yassine
authors.forename: Charles A
authors.initials: CA
authors.lastname: Lucy
mesh_terms: D053841:Electroosmosis; D019075:Electrophoresis, Capillary / Q000295:instrumentation* / Q000379:methods; D008051:Lipid Bilayers / Q000737:chemistry; D011506:Proteins / Q000302:isolation & purification*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D015203:Reproducibility of Results; D013499:Surface Properties; D013501:Surface-Active Agents / Q000737:chemistry*
chemical_list: D008051:Lipid Bilayers; D011506:Proteins; D000644:Quaternary Ammonium Compounds; D013501:Surface-Active Agents; C046112:didodecyldimethylammonium