Preparation of core-shell magnetic molecularly imprinted polymers for extraction of patulin from juice samples

In this study, a novel magnetic molecularly imprinted polymer (MMIP) was prepared by surface imprinting technology using 2-oxin and 6-HNA as dual virtual templates and 4-vinyl pyridine (4-VP) as the functional monomer for extraction of patulin (PAT) from the surface of magnetic nanoparticles. MMIPs were characterized by fourier transformed infrared (FT-IR) spectroscopy, X-ray diffraction, and vibrating sample magnetometry. The results showed that the molecularly imprinted polymer (MIP) was successfully coupled with magnetic nanoparticles and could be used as a magnetic selective recognition material. Moreover, MMIPs have a greater adsorption capacity for PAT than conventional MIPs. The magnetic dispersion solid-phase extraction procedure was optimized and then combined with liquid chromatography-tandem mass spectrometry (MDSPE-LC-MS/MS) for detection of PAT in juice samples. The method showed excellent analytical performance in terms of linearity (ranged between 0.5 μg L^-1 and 100 μg L^-1with correlation coefficients (r) higher than 0.999) and limit of detection (LOD) (0.1 μg L^-1, S/N = 3). At three spiking concentrations (1, 10, and 50 μg L^-1), the mean recoveries were ranged between 79.4% and 97.9% with relative standard deviations (RSDs) < 4.7% (n = 3).