Graphene oxide (GO) was conjugated to magnetite nanoparticles and then coated with poly(methyl methacrylate) to obtain a nanomaterial of the type PMMA@GO-Fe3O4, which is shown to be a viable sorbent for magnetic solid-phase extraction. The nanocomposite was characterized by SEM, TEM, XRD, VSM and FTIR spectroscopy. It was applied to the extraction of the aromatic amines aniline, N,N-dimethylaniline, o-toluidine, and 3-chloroaniline. Under optimal conditions, the preconcentration factors range from 139 to 173. Following desorption with dichloromethane, the amines were quantified by GC. Analytical figures of merit include (a) a linear range extending from 0.007–100 ng mL−1, (b) detection limits between 2 and 6 pg mL−1; and (c) relative standard deviations between 5.9 and 8.6% (for n = 5; at 0.05, 5.0 and 50 ng mL−1 levels, respectively). The method was successfully applied to the determination of aromatic amines in spiked real water samples and gave recoveries in the range of 90.3%–99.0%.

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