title: Silica-based monolithic capillary columns-Effect of preparation temperature on separation efficiency.
abstract: The temperature effects during the sol-gel process and ageing of the silica-based monolith on the structure and separation efficiency of the capillary columns (100microm i.d., 150mm) for HPLC separations were studied. The tested columns were synthesized from a mixture of tetramethoxysilane, polyethylene glycol and urea under the acidic conditions. The temperature was varied from 40 degrees C to 44 degrees C and formation of bypass channels between the silica mold and the capillary wall was examined. The temperature of 43 degrees C was estimated as optimal for preparation of efficient silica capillary columns which were subsequently modified by octadecyldimethyl-N,N-diethylaminosilane or covered by poly(octadecyl methacrylate) and tested using standard mixture of alkylbenzenes under the isocratic conditions.
authors.affiliation: Institute of Analytical Chemistry of the ASCR, Brno, Czech Republic. planeta@iach.cz
authors.forename: Josef
authors.initials: J
authors.lastname: Planeta
authors.forename: Dana
authors.initials: D
authors.lastname: Moravcová
authors.forename: Michal
authors.initials: M
authors.lastname: Roth
authors.forename: Pavel
authors.initials: P
authors.lastname: Karásek
authors.forename: Vladislav
authors.initials: V
authors.lastname: Kahle
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D044367:Phase Transition; D011092:Polyethylene Glycols / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D013696:Temperature; D014508:Urea / Q000737:chemistry
chemical_list: D001555:Benzene Derivatives; D012821:Silanes; D011092:Polyethylene Glycols; C061205:tetramethoxysilane; D012822:Silicon Dioxide; D014508:Urea