ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Using Fe₃O₄-graphene oxide-modified chitosan with melamine magnetic nanocomposite in the removal and magnetic dispersive solid-phase microextraction of Cr (VI) ion in aquatic samples

Vahid Bagheri, Abdolhossein Naseri, Sanaz Sajedi-Amin, Mustafa Soylak, and Zhaowei Zhang

Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran

E-mail: a_naseri@tabrizu.ac.ir

Received: 13 November 2022  Accepted: 17 September 2023

Abstract:

An eco-friendly magnetic nanoparticle (MNPs)-based stir rod-assisted dispersive solid-phase extraction (SRMDSPE) method was proposed for the removal and extraction of Cr (VI) preceding its spectrophotometric determination. The magnetic melamine‐functionalized chitosan-modified graphene oxide (MCMGO) nanocomposites were synthesized as a biocompatible, effective adsorbent with admirable adsorption capacity, great magnetic property and excellent dispersion ability for the adsorption of the Cr (VI) ion. The prepared adsorbent was characterized by XRD, FTIR, TGA, VSM, EDX, and SEM. Different parameters affecting removal and microextraction efficiencies such as sample volume, pH, interferences, volume and type of eluent, and adsorbent dosage were investigated and optimized. The result of isotherm shows that Cr (VI) adsorption followed the Freundlich model. Thermodynamic parameters (i.e., change in the free energy (ΔG⁰), the enthalpy (ΔH⁰), and the entropy (ΔS⁰)) were also evaluated. The overall adsorption process was endothermic and spontaneous. The sorbent elution with ability and reusability was used in dispersive solid-phase extraction. Under optimal conditions, the extraction efficiency was 78.0%, and the enrichment factor was 31.19. The SRMDSPE was successfully quantified in the 0.05–0.5 mg L⁻¹ (R² = 0.9993) with a detection limit of 0.015 mg L⁻¹. The proposed method was applied to leather wastewater, Tabriz, and some surface waters. The percentage of recoveries for spiked real samples were in the range of 91–101%, and the percentage of relative standard deviations were 2–6%.

Keywords: Dispersive solid-phase extraction; Magnetic nanocomposite; Chitosan-modified graphene oxide; Cr (VI); Adsorption; Preconcentration

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-03096-5

Chemical Papers 78 (1) 381–396 (2024)