Graphene‐grafted silica‐coated Fe₃O₄ nanoparticles as a magnetic solid‐phase extraction material coupled with inductively coupled plasma optical emission spectroscopy for the separation and analysis of heavy metal ions

Abstract

A novel method using graphene‐grafted silica‐coated Fe3O4 nanoparticles (Fe3O4‐SiO2‐G) as a magnetic solid adsorbent coupled with inductively coupled plasma atomic emission spectrometry for the separation and analysis of Mn(II), Cr(III), Pb(II) was developed. The introduction of graphene into Fe3O4‐SiO2 increased the selectivity and adsorption capacity of the developed material. The successful immobilization of graphene on the Fe3O4‐SiO2 was confirmed by X‐ray diffraction, transmission electron microscopy, size distribution and magnetic analysis and isoelectric point analysis. It was found that Mn(II), Cr(III), and Pb(II) could be determined with very good adsorption efficiencies (96.8, 100.0, 100.0%) on Fe3O4‐SiO2‐G. The limits of detection for the three metal ions were in the range of 0.076–0.922 ng ·L−1, and the linear range was 5.0–90.0 μg L−1 for Mn(II), 4.0–90.0 μg ·L−1 for Cr(III) and 5.0–90.0 μg ·L−1 for Pb(II). The enrichment factors of Mn(II), Cr(III), and Pb(II) were 80, 20, and 35, respectively. The developed method was successfully applied to the determination of Mn(II), Cr(III), and Pb(II) in real samples.