Magnetite–graphene oxide composites as a magnetic solid-phase extraction adsorbent for the determination of trace sulfonamides in water samples
A facile approach was used to prepare Fe3O4–graphene oxide (Fe3O4–GO) nanocomposites, and the application of these nanocomposites was investigated in the magnetic solid-phase extraction (MSPE) coupled with high-performance liquid chromatography with diode-array detection (HPLC-DAD) of three sulfonamides (SAs) from water samples. The Fe3O4–GO nanocomposites possess the advantages of both GO and Fe3O4. The Fe3O4–GO nanocomposites were characterized by scanning electron microscopy and vibrating-sample magnetometry. Sulfadiazine (SDZ), sulfadimidine (SDD) and sulfathiazole (STZ) were selected as target analytes to validate the extraction performance of the Fe3O4–GO nanocomposites as a MSPE adsorbent. The results indicated that the limits of detection of these sulfonamides were in the range of 0.05–0.10 μg mL−1, that the recoveries ranged between 67.4% and 119.9%, and that the linearity (R2 > 0.9900) and precision (between 0.04% and 9.03%) were good. The developed method can be used to determine and monitor SA residues in environmental water samples.