Preconcentration and Determination of Zearalenone in Corn Oil by a One-Step Prepared Polydopamine-Based Magnetic Molecularly Imprinted Polymer (MIP) with High-Performance Liquid Chromatography with Fluorescence (HPLC-FLD) Detection

A polydopamine-based molecularly imprinted polymer with quercetin as the mimic template was deposited on the surface of ferroferric oxide nanoparticles (Fe3O4@PDA MIPs) and used for the purification and enrichment of zearalenone prior to the determination by high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Adsorption experiments showed that the maximum capacity of Fe3O4@PDA MIPs toward zearalenone was 1.49 mg/g and the process matched the Langmuir isotherm model. Parameters of the analysis, such as the mass of MIPs, pH, ultrasonication time, elution solvent and volume, were optimized. Good linearity with the zearalenone concentration from 1 to 20 ng/mL was obtained (R = 0.9998). The limit of detection was 0.68 ng/mL. The recoveries from spiked corn oil samples were 93.8% to 101.0% with relative standard deviations from 6.5% to 9.1%. In addition, reusability experiments indicated that Fe3O4@PDA MIPs may be reemployed at least 7 times. These results demonstrate that the prepared Fe3O4@PDA MIPs were effective for the selective preconcentration of zearalenone from corn oil. The developed method was more reliable, faster, and lower cost than the National Standard Method of China.