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

Abstract

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 450nm, the imprinted molecular layer accounting for 10.7% of the total mass, and saturation magnetization of about 34.54emu/g. The maximum adsorption capacity (Qmax) of the thermodynamic and kinetic adsorption experiments were 13.90mg/g and 8.71mg/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 Qmax of 8.22mg/g and 15.37mg/g, respectively. In actual sample detection, the limit of detection (LOD) and limit of quantification (LOQ) were 0.4ng/kg and 0.9ng/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.