Synthesis of Mg(OH)2@Reduced graphene oxide nanocomposite and application for simultaneous micro solid phase extraction of uranium and thorium using micropipette tip syringe system

Abstract

Recently, nanoscale magnesium hydroxide (Mg(OH)2) has aroused widespread attention because of low-cost, environmental friendly, recyclable, large specific surface area, and extraction ability. It has been shown that Mg(OH)2 exhibits a hopeful prospect in removal of heavy metals, acid wastewater treatment, and decoloration of printing and dyeing wastewater [1]. Uranium and thorium are vital elements not only in industrial application but also in environmental and energy problems. However both of the metal ions are well-known to cause serious toxicological effects in human and their compounds are potential occupational carcinogens [2]. Based on the facts, highly selective and sensitive method for determination of uranium and thorium is blooming. In this work, Mg(OH)2@Reduced graphene oxide nanocomposite was synthesized using homogeneous precipitation and then consequent reduction with hydrazine hydrate and refluxing. This nanocomposite was characterized by using Fourier transform-infrared spectroscopy, X-ray diffraction and transmission electron microscopy. This nanocomposite exhibit good selectivity to uranium and thorium ions and applied for simultaneous micro solid phase extraction (μSPE) of these ions using micropipette tip syringe system. The effective parameters on μSPE were optimized using central composite design. The developed technique was applied to the determination of uranium and thorium in environmental water samples with satisfactory results. [1] Z. Zhuang, X. Ou, J. Li, Y. Zhou, Z. Zhang, S. Dong, Z. Lin, ACS Sustain. Chem. Eng., 4 (2015) 801. [2] A. Saha, S. B. Deb, A. Sarkar, M. K. Saxena, B. S. Toma, RSC Adv., 6 (2016) 20109.