Novel porous Fe3O4@C nanocomposite from magnetic metal-phenolic networks for the extraction of chlorophenols from environmental samples

Metal-organic coordination materials have received extensive attention because of their combined benefits of both inorganic and organic building blocks. In this work, the functional magnetic metal-phenolic networks with core-shell structure were prepared from phenolic ligand (tannic acid) and metal Zn2+ via self-assembly. The magnetic metal-phenolic networks consist of magnetic Fe3O4 core and metal-phenolic network shell which can act as carbon source. The Fe3O4@C nanocomposite was then synthesized by carbonizing the magnetic metal phenolic networks. The prepared Fe3O4@C had a high surface area and nanoscale porosity. It was successfully applied as the magnetic absorbent to enrich chlorophenols from environmental water and soil samples. Good response linearity for the analytes was observed in the range of 0.1-100.0 ng mL(-1) for water and 1.0-100.0 ng g(-1) for soil samples, with correlation coefficient >= 0.9989 and >= 0.9924, respectively. The limits of detection calculated at a signal-to-noise ratio of 3 (S/N = 3) were in the range from 0.01 to 0.03 ng mL(-1) for the water and 0.1-0.2 ng g(-1) for the soil sample, respectively. The relative standard deviations were below 6.8%.