Preparation of Dufulin imprinted polymer on surface of silica gel and its application as solid-phase extraction sorbent

A new molecularly imprinted polymer (MIP) based on silica-gel surface was developed using Dufulin (Duf) as a template, methacrylic acid (MAA) as a functional monomer, ethyleneglycol dimethacrylate (EGDMA) as a crosslinker, and azodiisobutyronitrile (AIBN) as an initiator. The synthetic samples were characterized by the techniques of Fourier transmission infrared spectrometry (FT-IR) and scanning electron microscope (SEM). Batch experiments were performed to evaluate adsorption isotherms, adsorption kinetics and selective recognition of the MIP. Binding experiments demonstrated that the MIP had a good adsorption capacity, fast mass transfer rate and high recognition selectivity to Dufulin. When the MIP was used as a solid-phase extraction (SPE) material, the recoveries of Dufulin for spiked water, soil and wheat samples were 88.98-102.16%, 85.31-99.57% and 87.84-100.19%, along with LOD of 0.0008 mg L-1, 0.010 mg kg(-1) and 0.023 mg kg(-1), respectively. Compared with direct determination of HPLC without MIP-SPE, the highly selective separation and enrichment of Dufulin from the complex environmental media can be achieved by the newly developed molecular imprinting at the surface of silica gel.