Determination of Arsenic in Milk by Magnetic Solid-Phase Extraction (MSPE) with Novel Iron (II, III) Nanoparticles Coated with Tween 80

Magnetic Fe3O4 nanoparticles coated with Tween 80 (polyoxyethylene sorbitan monooleate) were synthesized and used in solid-phase extraction for arsenic adsorption. The nanoparticles were characterized by field emission scanning electron microscopy (FESEM), energy dispersive x-ray spectroscopy (EDX), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). The arsenic concentration was determined by an ultrasonic nebulizer combined with inductively coupled plasma - optical emission spectrometry (USN-ICP-OES). The optimized conditions in the study were pH 2, 10 mg adsorbent, and 30 min of contact time. The adsorption of As(III) from aqueous solution was investigated. Additionally, adsorption isotherms and kinetics, foreign ions, and analytical value studies were performed under optimized conditions. The enrichment factor, limit of detection, and relative standard deviation were 35, 1.58 mu g.L-1, and 0.81% for As(III). The method is compatible with the Langmuir isotherm model. Milk was analyzed for As(III) using magnetic solid phase extraction. The levels of As(III) in milk from Sakarya were below the permissible limits.