Synthesis and characterization of core–shell magnetic molecularly imprinted polymers for selective recognition and determination of quercetin in apple samples

Magnetic molecularly imprinted polymers (M-MIPs) with core–shell structure were prepared through the surface molecular imprinting technique by using quercetin as the template molecule. The resultant Fe3O4@MIPs were characterized using X-ray diffraction, Fourier transform infrared spectrum, transmission electron microscopy, and vibrating sample magnetometer. The Fe3O4@MIPs possessed high adsorption capacity and specific recognition for quercetin. The maximum adsorption capacity of Fe3O4@MIPs towards quercetin was 10.52 mg/g, and could reach binding equilibrium within 30 min. The selectivity and specific recognition ability of Fe3O4@MIPs were evaluated according to their recognition to quercetin and its analogues. The Fe3O4@MIPs were successfully applied as selective sorbents to extract and determine quercetin from apple samples with a relatively high recoveries (89.2–93.6%) and relative standard deviations of <5%. The obtained Fe3O4@MIPs have potential application for quercetin determination in real samples.