title: Comparison of thermal- and photo-polymerization of lauryl methacrylate monolithic columns for CEC.
abstract: Lauryl methacrylate-based (LMA) monolithic columns for CEC, prepared using either thermal initiation or by UV-irradiation in the presence of AIBN have been compared. Thermal polymerization was carried out at 70 degrees C for 20 h. For UV initiation, the effects of the time exposure to UV light and irradiation energy were investigated. For each initiation process, the influence of composition of porogenic solvent (1,4-butanediol/1-propanol ratio) on the physical and electrochromatographic properties of the resulting monoliths was also evaluated. Photochemically lauryl methacrylate stationary phases initiated showed higher permeabilities and better efficiencies than those prepared by thermal initiation. After optimization of polymerization mixture, photopolymerized columns provided a permeability of 4.25 x 10(-13) m(2) and a minimum plate height of 13.4 microm for a mixture of polycyclic aromatic hydrocarbons. Similar column-to-column and batch-to-batch reproducibilities, with RSD values below 11.6 and 11.0 % for the thermal- and UV-initiated columns, respectively, were obtained.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Valencia, Valencia, Spain.
authors.forename: Virginia
authors.initials: V
authors.lastname: Bernabé-Zafón
authors.forename: Amparo
authors.initials: A
authors.lastname: Cantó-Mirapeix
authors.forename: Ernesto F
authors.initials: EF
authors.lastname: Simó-Alfonso
authors.forename: Guillermo
authors.initials: G
authors.lastname: Ramis-Ramos
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Herrero-Martínez
mesh_terms: D002072:Butylene Glycols / Q000737:chemistry; D053801:Capillary Electrochromatography / Q000379:methods*; D008689:Methacrylates / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D055668:Photochemical Processes; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D011109:Polymethacrylic Acids / Q000138:chemical synthesis*; D015203:Reproducibility of Results; D013696:Temperature; D014466:Ultraviolet Rays
chemical_list: D002072:Butylene Glycols; D008689:Methacrylates; D011084:Polycyclic Aromatic Hydrocarbons; D011109:Polymethacrylic Acids; C115846:dodecyl methacrylate; C039681:1,4-butanediol