title: Alkylated poly(styrene-divinylbenzene) monolithic columns for mu-HPLC and CEC separation of phenolic acids.
abstract: Macroporous poly(styrene-divinylbenzene) monolithic columns were prepared in fused silica capillaries of 100 microm id by in-situ copolymerization of styrene with divinylbenzene in the presence of propan-1-ol and formamide as the porogen system. The monoliths were subsequently alkylated with linear alkyl C-18 groups via Friedel-Crafts reaction to improve the retention and chromatographic resolution of strongly polar phenolic acids. A new thermally initiated grafting procedure was developed in order to shorten the time of the alkylation process. The grafting procedure was optimized with respect to the reaction temperature, time, the grafting reactant concentration, and the solvent used. The type of solvent and the grafting temperature are the most significant factors affecting the hydrodynamic properties, porosity, and efficiency of the columns. While the equivalent particle diameter of the grafted column increased, the capillary-like flow-through pore diameter decreased in comparison to non-alkylated monoliths. The hydrodynamic permeability of the monolith decreased, but the monolithic column still permitted fast micro-HPLC separations.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Pardubice, Czech Republic.
authors.forename: Zdenka
authors.initials: Z
authors.lastname: Kucerová
authors.forename: Michal
authors.initials: M
authors.lastname: Szumski
authors.forename: Boguslaw
authors.initials: B
authors.lastname: Buszewski
authors.forename: Pavel
authors.initials: P
authors.lastname: Jandera
mesh_terms: D000478:Alkylation; D053801:Capillary Electrochromatography / Q000295:instrumentation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D003373:Coumaric Acids / Q000032:analysis; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000032:analysis; D062385:Hydroxybenzoates / Q000032:analysis*; D010316:Particle Size; D011137:Polystyrenes / Q000138:chemical synthesis* / Q000737:chemistry*; D016062:Porosity; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013499:Surface Properties; D013997:Time Factors; D014641:Vanillic Acid / Q000032:analysis
chemical_list: D003373:Coumaric Acids; D062385:Hydroxybenzoates; D011137:Polystyrenes; D005707:Gallic Acid; C003771:Amberlite XAD-2 resin; C004999:ferulic acid; C001945:syringic acid; D014641:Vanillic Acid; C017616:phenolic acid