Magnetic solid-phase extraction of polycyclic aromatic hydrocarbons using a graphene oxide/Fe3O4@polystyrene nanocomposite.

A magnetic sorbent was fabricated by coating the magnetized graphene oxide with polystyrene (PS) to obtain a sorbent of the type GO-Fe3O4@PS. The chemical composition and morphology of the sorbent were characterized. The sorbent was employed for the enrichment of polycyclic aromatic hydrocarbons (PAHs) from water samples. Various parameters affecting the enrichment were investigated. The PAHs were then quantified by gas chromatography with flame ionization detection. Linear responses were found in the range of 0.03-100 ng mL-1 for naphthalene and 2-methylnaphthalene, and of 0.01-100 ng mL-1 for fluorene and anthracene. The detection limits (at an S/N ratio of 3) range between 3 and 10 pg mL-1. The relative standard deviations (RSDs) for five replicates at three concentration levels (0.05, 5 and 50 ng mL-1) of analytes ranged from 4.9 to 7.4%. The method was applied to the analysis of spiked real water samples. Relative recoveries are between 95.8 and 99.5%, and RSD% are <8.4%. Graphical abstract A magnetic sorbent was fabricated by polystyrene coated on the magnetic graphene oxide for the extraction and preconcentration of PAHs in water samples prior to their determination by gas chromatography with flame ionization detection.