title: Development of magnetic graphene oxide adsorbent for the removal and preconcentration of As(III) and As(V) species from environmental water samples.
abstract: New-generation adsorbent, Fe3O4@SiO2/GO, was developed by modification of graphene oxide (GO) with silica-coated (SiO2) magnetic nanoparticles (Fe3O4). The synthesized adsorbent was characterized using Fourier transform infrared spectroscopy, X-ray diffractometry, energy-dispersive X-ray spectroscopy, and field emission scanning electron microscopy. The developed adsorbent was used for the removal and simultaneous preconcentration of As(III) and As(V) from environmental waters prior to ICP-MS analysis. Fe3O4@SiO2/GO provided high adsorption capacities, i.e., 7.51 and 11.46 mg g(-1) for As(III) and As(V), respectively, at pH 4.0. Adsorption isotherm, kinetic, and thermodynamic were investigated for As(III) and As(V) adsorption. Preconcentration of As(III) and As(V) were studied using magnetic solid-phase extraction (MSPE) method at pH 9.0 as the adsorbent showed selective adsorption for As(III) only in pH range 7-10. MSPE using Fe3O4@SiO2/GO was developed with good linearities (0.05-2.0 ng mL(-1)) and high coefficient of determination (R (2) = 0.9992 and 0.9985) for As(III) and As(V), respectively. The limits of detection (LODs) (3× SD/m, n = 3) obtained were 7.9 pg mL(-1) for As(III) and 28.0 pg mL(-1) for As(V). The LOD obtained is 357-1265× lower than the WHO maximum permissible limit of 10.0 ng mL(-1). The developed MSPE method showed good relative recoveries (72.55-109.71 %) and good RSDs (0.1-4.3 %, n = 3) for spring water, lake, river, and tap water samples. The new-generation adsorbent can be used for the removal and simultaneous preconcentration of As(III) and As(V) from water samples successfully. The adsorbent removal for As(III) is better than As(V).
authors: Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM, Johor Bahru, Johor, Malaysia.
authors: Hamid
authors: H
authors: Rashidi Nodeh
authors: Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM, Johor Bahru, Johor, Malaysia. wanaini@kimia.fs.utm.my.|Separation Science and Technology Group, Frontier Materials Research Alliance, Universiti Teknologi Malaysia, 81310 UTM, Johor Bahru, Johor, Malaysia. wanaini@kimia.fs.utm.my.
authors: Wan Aini
authors: http://orcid.org/0000-0002-0991-770X
authors: WA
authors: Wan Ibrahim
authors: Department of Chemistry, Jamia Millia Islamia (Central University), New Delhi, 110025, India.
authors: Imran
authors: I
authors: Ali
authors: Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM, Johor Bahru, Johor, Malaysia.|Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia, 81310 UTM, Johor Bahru, Johor, Malaysia.
authors: Mohd Marsin
authors: MM
authors: Sanagi
mesh_terms: D000327:Adsorption; D001151:Arsenic / Q000302:isolation & purification*; D006108:Graphite / Q000737:chemistry*; D007700:Kinetics; D057230:Limit of Detection; D008280:Magnetics; D010087:Oxides / Q000737:chemistry; D052616:Solid Phase Extraction / Q000379:methods; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D010087:Oxides; D014874:Water Pollutants, Chemical; D006108:Graphite; D001151:Arsenic
keywords: Adsorption isotherm; As(III) and As(V) removal; Kinetic; Magnetic graphene oxide; Magnetic nanoparticles; Magnetic solid-phase extraction; Thermodynamic