Recovery and separation of erythromycin from industrial wastewater by imprinted magnetic nanoparticles that exploit beta-cyclodextrin as the functional monomer

A type of surface imprinting over magnetic Fe3O4 nanoparticles utilizing erythromycin-A as a template for use in the separation and recovery of erythromycin was developed and investigated. As the intermolecular forces play a key role in the performance of imprinted materials, differential scanning calorimetry, and H-1 NMR spectroscopy was employed to evaluate the interactions between erythromycin and the functional monomer beta-cyclodextrin. To synthesize the surface imprinted polymers, magnetic Fe3O4 nanoparticles, the core materials, were modified with a free radical initiator to initialize polymerization in a grafting from manner. Then using acryloyl-modified beta-cyclodextrin as the functional monomer and ethyleneglycol dimethacrylate as the cross-linker, thin erythromycin-imprinted films were fabricated by the radical-induced graft copolymerization of monomers on the surface of the Fe3O4 nanoparticles. Selectivity experiments showed that the erythromycin-A-imprinted materials had recognition ability toward erythromycin derivatives. Finally, these magnetic molecularly imprinted particles were successfully used for the separation and enrichment of erythromycin from the mother liquor. The recovery, detected by high-performance liquid chromatography and differential pulse voltammetry, approached 97%. The combination of the specific selectivity of the imprinted material and the magnetic separation provided a powerful tool that is simple, flexible, and selective for the separation and recovery of erythromycin.