A layered magnetic iron/iron oxide nanoscavenger for the analytical enrichment of ng-L−1 concentration levels of heavy metals from water

Magnetically driven separation techniques have received considerable attention in recent decade because of their great potential application. In this study, we investigate the application of an unmodified layered magnetic Fe/Fe2O3 nanoscavenger for the analytical enrichment and determination of sub-parts per billion concentrations of Cd(II), Pb(II), Ni(II), Cr(VI) and As(V) from water samples. The synthesized nanoscavenger was characterized by BET, TGA, XRD and IR and the parameters influencing the extraction and recovery of the preconcentration process were assessed by atomic absorption spectrometry. The possible mechanism of the enrichment of heavy metals on Fe/Fe2O3 was proposed, which involved the dominant adsorption and reduction. The nanoscale size offers large surface area and high reactivity of sorption and reduction reactions. The obtained limits of detection for the metals studied were in the range of 20–125 ng L−1 and the applicability of the nanomaterial was verified using a real sample matrix. The method is environmentally friendly as only 15 mg of nanoscavenger are used, no organic solvent is required for the extraction and the experiment is performed without the need for filtration or preparation of packed preconcentration columns.

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► A layered magnetic Fe/Fe2O3 nanomaterial is prepared.
► Analytical enrichment of selected heavy metals on Fe/Fe2O3 nanoparticles.
► The mechanism of enrichment involves the adsorption and reduction.
► The applicability of the nanomaterial is verified using a real sample matrix.