Abstract: The molecularly imprinted microspheres(MIMs) for high performance liquid chromatography were synthesized by aqueous micro-suspension polymerization. The acidic indometacin, one of the antidepressants, was used as the template and basic 4-vinylpyridine was used as functional monomer. The influences of pH of mobile phase on the capacity factor(k′), separation factor(α) and selection factor(β) of indometacin were investigated in detail. All the results showed that the MIMs exhibited specific recognition and affinity to indometacin only in pH<4.0 eluent; and the specific recognition of MIMs was lost gradually in pH>4.0 eluent. By comparing the retention behavior of indometacin and 4-aminopyridine (4-AP) on the MIMs column, it proved that the recognition of MIMs to indomeatcin synthesized by 4-vinylpyridine as a cross-linker mainly relied on the ion-pair interaction between the nitrogen atom on the pyridine ring and the carboxyl on the indometacin, and the π-π interaction between the pyridine ring and the template molecule. This was just contrary to that MIMs synthesized by methacrylic acid as the cross-linker.

Key words: Molecularly imprinted microspheres(MIMs), Molecularly imprinted polymers(MIPs), Aqueous suspension polymerization, Indometacin