Abstract: Surface molecularly imprinted polymer(H-SiO2@MIP) based on hybrid silica microspheres was prepared by using di(2-ethylhexyl)phthalate(DIOP) as the template molecule, methacrylic acid(MAA) as the functional monomer and ethylene glycol dimethacrylate(EGDMA) as the cross-linking agent. The H-SiO2@MIP was characterized by scanning electron microscope(SEM) and infrared spectroscopy(IR). The results showed that DIOP imprinted layer was grafted on particles surface successfully. The H-SiO2@MIP has uniform spherical structure and the thickness of imprinted shell is about 60~70 nm. The adsorption properties were investigated by high performance liquid chromatography, and results demonstrated that the H-SiO2@MIP exhibited specific selectivity towards DIOP. The maximum adsorption capacity of H-SiO2@MIP was 50.35 mg/g, and the selectivity factor of DIOP towards dibutyl phthalate(DBP) and dimethyl phthalate(DEP) was 2.31 and 2.47, respectively. Packed into a solid-phase extraction(SPE) column, the H-SiO2@MIP could separate and enrich DIOP from milk sample.

Key words: imprinted polymer, di(ethylhexyl)phthalate, surface imprinting, solid-phase extraction