Synthesis and characterization of a nanomagnetic ion imprinted polymer for selective extraction of silver ions from aqueous samples

A magnetic ion imprinted polymer (mag-IIP) for the selective extraction of silver ions was synthesized by using functionalized magnetite (Fe3O4) nanoparticles as the magnetic core, silver ion as the template, salen as the ligand, 4-vinylpyridine as the functional monomer, and ethylene glycol dimethacrylate as the cross linker. A magnetic non-imprinted polymer was also prepared by an analogous procedure. The mag-IIP was characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction analysis, thermal analysis and scanning electron microscopy. The silver ions retained by the mag-IIP were eluted using the thiourea solution at a pH of similar to 3 and then determined by the flame atomic absorption spectrometry. The conditions for the extraction and preconcentration were optimized. The maximum sorption capacity of the mag-IIP is 28.2 mg g(-1) of Ag(I) ions. When preconcentrating a 150 mL sample, the enhancement factor is 293, and the detection limit is 50 ng L-1. The method was successfully applied to the determination of silver ions in (spiked) water samples and in the certified reference materials BCR 288 and CPB-1.