Development of hydrophilic magnetic molecularly imprinted polymers by directly coating onto Fe3O4 with a water-miscible functional monomer and application in a solid-phase extraction procedure for iridoid glycosides

Abstract

Hydrophilic magnetic molecularly imprinted polymers (HMMIPs) have been synthesized by directly coating onto Fe₃O₄ alkenyl glycosides glucose as a novel water-miscible functional monomer, which introduces an abundance of hydrophilic groups into polymers. Photographs of the dispersion properties and water contact angles demonstrated that these HMMIPs have excellent hydrophilicity compared with those prepared using the traditional hydrophilic functional monomer, methacrylic acid. HMMIPs were characterized by Fourier transform infrared spectroscopy, vibrating sample magnetometry, transmission electron microscopy, scanning electron microscopy, and X-ray diffraction. Binding experiments indicated that HMMIPs had an excellent imprinting effect and high selectivity. Under optimum magnetic molecular imprinted solid phase extraction (MMISPE) conditions, a wide linear range (0.01–50.0 μg mL⁻¹), with low limits of detection and quantification (0.005–0.01 μg mL⁻¹ and 0.019–0.033 μg mL⁻¹, respectively), was achieved for eight iridoid glycosides (IGs). Typical chromatograms obtained using MMISPE showed that major interferences around the IGs were eliminated efficiently and matrix interference was minimized. The results suggest that our newly developed method, combining MMISPE with HPLC, could be used for the selective enrichment and determination of IGs.