Abstract:

Puerarin-imprinted polymer microspheres (MIPM) were prepared by precipitation polymerization technique using
puerarin, methacrylic acid (MAA) and ethylene glycol dimethylacrylate (EGDMA) as the template, functional monomer and
cross-linker, respectively. Scanning electron microscope (SEM) was used for evaluating the morphology of polymer and a
static method was used for characterizing the adsorption behavior. The application of the MIPM for adsorption, desorption
and solid phase extraction of puerarin from crude pueraria root extract was explored. Results indicated that the adsorption
capacity for the optimized MIPM (MIP3) toward the pure template reached 37.9 mg/g, with an adsorption percentage of
(96.3 ± 1.81)% toward the target compound in the crude extract. The desorption percentage varied within the range of
27%–34% when water, methanol-acetic acid (9:1, V/V ) and 50% aqueous methanol were used as the eluents, respectively.
Furthermore, the product desorbed from the MIP3 using water as the eluent contained the highest content of puerarin
(37.4 ± 2.87)%. Puerarin product with 75% purity can be obtained by MIP3 using single-step solid phase extraction with a
puerarin recovery of 71.6%.

Key words: molecularly imprinted polymer, puerarin, precipitation polymerization, adsorption, solid phase extraction