Magnetic solid-phase extraction of brominated flame retardants from environmental waters with graphene-doped Fe3O4 nanocomposites

Graphene-doped Fe3O4 nanocomposites were prepared by a solvothermal reaction of an iron source with graphene. The nanocomposites were characterized by transmission electron microscopy, atomic force microscopy, X-ray diffraction, superconducting quantum interference, Raman spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. This nanomaterial has been used as a magnetic solid-phase extraction sorbent to extract trace brominated flame retardants from environmental waters. Various extraction parameters were optimized including dosage and reusability of the nanocomposites, and pH of sample matrix. The reliability of the magnetic solid-phase extraction protocol based on graphene-doped Fe3O4 nanocomposites was evaluated by investigating the recoveries of 2,4,6-tribromophenol, tetrabromobisphenol A, 4-bromodiphenyl ether, and 4,4'-dibromodiphenyl ether in water samples. Good recoveries (85.0-105.0%) were achieved with the relative standard deviation ranging from 1.1-7.1%. Moreover, it is speculated from characterization and magnetic solid-phase extraction experiment that there is not only pi-pi stacking but also possible hydrophobic interaction between the graphene-doped Fe3O4 nanocomposites and analytes.