Magnetic graphene solid-phase extraction in the determination of polycyclic aromatic hydrocarbons in water

In this work, magnetic graphene nanocomposite Fe3O4/rGO was fabricated by using a solvothermal method and applied to the magnetic solid-phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) in environmental water samples, followed by gas chromatography-mass spectrometry (GC-MS). Several parameters affecting the extraction efficiency, such as amount of magnetic graphene, extraction time, desorption conditions, were studied in detail. The results showed that Fe3O4 /rGO has an extremely high adsorption capacity for PAHs, only 10 mg of the adsorbent was needed for 100 mu L of water sample, and the PAHs could be completely desorbed with 100 mL of desorption solvent. Under the optimized conditions, a good linearity was obtained in the concentration range of 0.005-5 mu g L-1 for 10 low ring PAHs from naphthalene to chrysene, 0.1-5 mu g L-1 for benzo[b] fluoranthene, benzo[k] fluoranthene and benzo(a) pyrene. The limits of detection (LOD, S/N = 3) of the method were in the range between 0.02-14.3 ng L-1. The recoveries for PAHs tested in spiked water samples were in the range 75.6-112.4% with relative standard deviations (RSD) ranging from 0.1-9.5%. Finally, the method was successfully applied for the analysis of real water samples in the search for PAHs.