The Synthesis And Applications Of Molecularly Imprinted Polymeric Microspheres

In this paper, the molecularly imprinted polymeric microspheres (MIPMs) were synthesized by precipitation polymerization, using mefenamic acid (MFA), L-methyldopa (LMD) and 10-hydroxycamptothecin (10-HCPT) as templates, methacrylic acid (MAA), 4-vinyl pyridine (4-VP) and acrylamide (AM) as functional monomers, ethylene glycol dimethyl acrylate (EGDMA) and divinyl benzene (DVB) as crosslinkers in different porogen, including acetonitrile, acetonitrile/chloroform,acetonitrile/toluene,acetonitrile/methanol,acetonitrile/chloroform/methanol, acetonitrile/toluene/methanol and acetonitrile/pyridine. The shape and methodolodgy of MIPMs were characterized using scanning electron microscopy (SEM). To synthesize above 3μm in diameter for MIPMs, the synthetic conditions of precipitation polymerization were investigated and explored in detail. The sizes of MIPMs were affected differently by the kinds and amounts of monmers, crosslinkers and porogens depending on the kinds of template molecules. For MFA, 3-5μm of MIPMs could be obtained when AM and DVB were used as functional monomer and crosslinker, respectively, in a mixture porogen of acetonitrile and chloroform (3:1, V/V). For LMD,3-7μm of MIPMs could be obtained when MAA and DVB were used as functional monmer and crosslinker, respectively, in a mixture porogen of acetonitrile/chloroform/methanol (10.64:3.54:1, V/V/V). For 10-HCPT, 3-5μm of MIPMs were achieved when MAA and DVB were used as functional monomer and crosslinker in a mixture porogen of acetonitrile/chloroform/methanol (12:4:1, V/V/V).The MIPMs of LMD and 10-HCPT were packed into column used as solid-phase extraction (SPE) materials, the loading, cleaning and eluating conditions were optimized. The saturated adsorption capacity (Q) of MIPMs and NIPMs for LMD were 16.46μmol/g and 14.96μmol/g, respectively, and the imprinting factor (α) is 1.1. The saturated adsorption capacity Q of MIPMs and NIPMs for 10-HCPT were 10.59μmol/g and 9.63μmol/g, respectively, and the imprinting factor (α) is 1.1. The primary SPE results indicate that the LMD in mimic urine could be separated and enriched on the MIPMs column of LMD and the interferences of impurities in urine could be eliminated roughly.