title: Open tubular columns with mixed-mode reversed-phase and weak anion-exchange stationary phase for capillary electrochromatography.
abstract: Columns for open tubular capillary electrochromatography, coated with a mixed-mode (RP/ion-exchange) stationary phase, were prepared by using the sol-gel method. The synthetic procedure was optimized by changing the ratios of tetraethoxysilane, octyltriethoxysilane, and 3-aminopropyltriethoxysilane in the initial sol. SEM studies reveal that a coating with about 400 nm thickness can be obtained. The inner surface properties of these capillaries were probed by measuring the EOF as a function of pH. The surface of this stationary phase contains octyl, amine, and residual silanol moieties; the amine and silanol groups determine the net charge on the inner surface of the capillary and can produce a switchable EOF (anodal/cathodal). The performances of the columns were evaluated by open tubular capillary electrochromatography using a wide range of compounds (polycyclic aromatic hydrocarbons, aromatic acids, and aromatic amines).
authors.affiliation: Department of Chemistry and Institute of Biomedical Science, Fudan University, Shanghai, P. R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Lei
authors.forename: Xiangmin
authors.initials: X
authors.lastname: Zhang
mesh_terms: D000588:Amines / Q000032:analysis; D000837:Anion Exchange Resins / Q000737:chemistry*; D053801:Capillary Electrochromatography / Q000295:instrumentation* / Q000379:methods; D019075:Electrophoresis, Capillary / Q000379:methods; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D013499:Surface Properties
chemical_list: D000588:Amines; D000837:Anion Exchange Resins; D011084:Polycyclic Aromatic Hydrocarbons