Preparation of magnetic molecularly imprinted polymers for the identification of zearalenone in grains

This study was based on the specific binding ability of magnetic molecularly imprinted polymers (MMIPs) combined with a high-performance liquid chromatography-fluorescence detector (HPLC-FLD) for the rapid determination of zearalenone (ZEN) in cereals. A novel magnetic molecularly imprinted polymer was prepared by surface imprinting technology. Warfarin was used as a virtual template, 3-aminopropyl triethoxysilane (APTES) was used as the functional monomer, and tetraethyl orthosilicate (TEOS) was used as the cross-linking agent. Analysis by a vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) showed that MMIPs were prepared with a particle size about 450 nm, the imprinted molecular layer accounting for 10.7% of the total mass, and saturation magnetization of about 34.54 emu/g. The maximum adsorption capacity ( Q max ) of the thermodynamic and kinetic adsorption experiments were 13.90 mg/g and 8.71 mg/g, respectively. The Langmuir model showed that the binding sites were uniformly distributed on the surface of the MMIPs. The Scatchard analysis showed that MMIPs had two types of binding sites with Q max of 8.22 mg/g and 15.37 mg/g, respectively. In actual sample detection, the limit of detection (LOD) and limit of quantification (LOQ) were 0.4 ng/kg and 0.9 ng/kg, respectively. The sample recovery rate was 90.56–99.96%, the daytime stability was 1.35–2.87%. These results showed that MMIPs had good performance in selectively identifying ZEN and were suitable for determining ZEN in cereals.