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 h igh performance liquid chromatography (HPLC) is described. Several silica b eads with various degrees of beta-CD were synthesized using the coating tec hnology. These HPLC phases were based on silica beads coated with the copol ymer vinylamine-vinyl alcohol (VAM-VAL). In order to obtain stationary phas es with a high capacity in beta-CD and maximum accessibility of the beta-CD cavity, the functionalization was carried out after the coating and crossl inking steps, using the mono-tosyl derivative of beta-CD as the intermediat e. Several factors (reaction time, temperature, solvent and amounts of reac tants) have been studied. A characterization was carried using surface area , pore size distribution, and solid state NMR spectroscopy. The liquid chro matographic separation by isocratic elution of aromatic compounds by using these supports is also presented.