Fe3O4–SiO2–graphene oxide–amino acid ionic liquid magnetic solid-phase extraction combined with inductively coupled plasma optical emission spectrometry for speciation of Cr(iii) and Cr(vi) in environmental water

Abstract

Magnetic graphene oxide coated with amino acid ionic liquid (Fe₃O₄–SiO₂–GO–AAIL) as a solid extractant combined with inductively coupled plasma optical emission spectrometry (ICP-OES) has been developed for the speciation analysis of Cr(III) and Cr(VI) in water samples. Cr(III) could be selectively extracted on Fe₃O₄–SiO₂–GO–AAIL at pH 9.0. Under the optimum conditions, the developed method provides linear ranges from 6.0 to 650.0 μg L⁻¹ for Cr(III) and from 3.0 to 350.0 μg L⁻¹ for Cr(VI). The limits of detection (LODs) are 0.406 and 0.186 μg L⁻¹ for Cr(III) and Cr(VI), respectively, with an enrichment factor of 25.7. This approach has been validated through the quantitation of Cr(III) and Cr(VI) in environmental water samples, with satisfactory recoveries in the range of 88.3–106.2% for Cr(III) and 82.9–111.8% for Cr(VI). This developed magnetic solid phase extractant coupled with ICP-OES method shows a promising future in the field of environmental remediation.