Beta-cyclodextrin-copolymers coated on silica beads: Synthesis, characterization and retention behavior in HPLC

The synthesis of beta-cyclodextrin (beta-CD)-bonded stationary phases for high performance liquid chromatography (HPLC) is described. Several silica beads with various degrees of beta-CD were synthesized using the coating technology. These HPLC phases were based on silica beads coated with the copolymer vinylamine-vinyl alcohol (VAM-VAL). In order to obtain stationary phases with a high capacity in beta-CD and maximum accessibility of the beta-CD cavity, the functionalization was carried out after the coating and crosslinking steps, using the mono-tosyl derivative of beta-CD as the intermediate. Several factors (reaction time, temperature, solvent and amounts of reactants) have been studied. A characterization was carried using surface area, pore size distribution, and solid state NMR spectroscopy. The liquid chromatographic separation by isocratic elution of aromatic compounds by using these supports is also presented.