Characteristics of a monolithic molecularly imprinted column and its application for chromatographic separation

Monolithic molecularly imprinted columns were designed and prepared by in situ thermal-initiated copolymerization for rapid separation of the xanthine derivatives such as caffeine, theobromine, and theophylline., Molecular recognition was found to be dependent on the structures and arrangements of functional groups of the imprinted molecule and the cavities of the MIR The morphological characteristics of the monolithic MIP were investigated using scanning electron microscopy, which showed that both mesopores and macropores were formed in the imprinted monolith. The effects of the chromatographic separation conditions on the molecular recognition were investigated; hydrogen bonding and hydrophobic interactions played an important role in the retention and separation. Thermodynamic data (Delta Delta H and Delta Delta S) obtained from Van't Hoff plots revealed an enthalpy-controlled separation. The present method is very simple compared with the bulk MIP procedure; the macroporous structure has excellent separation properties.