Preparation and characterization of molecularly imprinted monolithic column based on 4-hydroxybenzoic acid for the molecular recognition in capillary electrochromatography

A novel prepared method of molecularly imprinted monolithic polymers (MIPs) using 4-hydroxybenzoic acid (4-HBA) as templates for capillary electrochromatography (CEC) was developed. A strategy of high concentration of monomers in the pre-polymerization mixture was used to fulfil the solubility of polar imprinted molecule and reduction of the interference during complex formation. The imprinted polymer capillary monolithic column was synthesized by an in situ therm-initiated copolymerization of methacrylic acid (MAA) and ethylene glycol dimethacrylate with a mixture of toluene-isooctane as a porogenic solvent in the presence of a polar model imprinting molecule, 4-HBA. On the resultant MIP monolithic column, the effect of parameter of CEC on electroosmotic flow (EOF) and the retention of 4-HBA was investigated. The column efficiency of the imprinted molecule, 4-HBA, was 13,000 plates/m. The resolution of isomers of HBA was 5.0 and good molecular recognition was achieved for 4-HBA.