Preparation of magnetic molecularly imprinted polymers with double functional monomers for the extraction and detection of chloramphenicol in food

In this study, an efficient, selective, and simple analytical method for the extraction of chloramphenicol (CAP) from food using magnetic molecularly imprinted polymers (MMIPs) as the solid-phase extraction (SPE) sorbent was successfully developed. MMIPs with varying ratios of methacrylic acid to acrylamide were prepared by suspension polymerization on the surface of double-bond-modified Fe3O4 magnetic nanoparticles. Further, these MMIPs were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy, as well as using a vibrating sample magnetometer. Furthermore, the adsorption capacities of MMIPs and MNIPs were investigated by binding experiments. Methodology evaluation for the detection of CAP from food was carried out using MMIPs as the SPE sorbent. By using an external magnetic field, MMIPs were separated by a simple and rapid method. The diameter of the so-obtained MMIPs, exhibiting good monodispersity, was 400-700 nm. The MMIPs exhibited the maximum apparent adsorption capacity of up to 42.60 mg g−1 with good selectivity. For the detection of food samples, the linear response range was 0.02-10.00 mg L−1, with a detection limit of 10 μg L−1, and intra- and inter-day stabilities ranged from 1.34% to 1.89% and from 1.76% to 2.77%, respectively, with good recoveries (95.31%-106.89%) and satisfactory relative standard deviations (1.21%-2.60%).