Abstract: In this experiment, molecularly imprinted polymers (MIPs) were prepared by precipitation polymerization using synephrine as a template molecule, acrylic acid and hydroxyethyl acrylate as bifunctional monomers, azobisisobutyronitrile as an initiator, and ethylene glycol dimethacrylate as a crosslinking agent. The synthesis conditions were optimized through static adsorption experiments. The maximum adsorption capacity and specific recognition performance were evaluated under optimized conditions, and the adsorption mechanism was explored. The morphology of the synthesized polymer was characterized by scanning electron microscopy, and its application as a solid phase extraction (SPE) sorbent for separating synephrine extracted from Fructus Aurantii immaturus was investigated. MIPs with good morphology and specific recognition capacity (maximum adsorption capacity of 228.82 μmol/g) for synephrine were obtained using 10 mL of acetonitrile as porogen at a molar ratio of template molecule to functional monomer to initiator to cross-linker of 1:4:2:20. After being purified with the SPE sorbent, the purity of synephrine increased from 1.93% to 93.34% with a recovery of 73.90%.

Key words: molecular imprinting, synephrine, solid phase extraction, specific recognition