Modifying Fe3O4 microspheres with rhodamine hydrazide for selective detection and removal of Hg2+ ion in water

Rhodamine hydrazide modifying Fe3O4 microspheres (Fe3O4-R6G) was developed for selective detection and removal of mercury ion from water. With a saturation magnetization of 74.2 emu/g, the Fe3O4-R6G could be simply recollected from water with magnetic separation within a few minutes. The selectivity and adsorption ability of Fe3O4-R6G for metal cations were studied by fluorophotometry and atomic absorption spectrometry, respectively. The results showed that Fe3O4-R6G exhibited excellent selectivity for sensing mercury ion over other metal ions in aqueous solution, and also adsorbed 91% of mercury ion. The maximum adsorption capacity of the Fe3O4-R6G for Hg2+ ion was 37.4 mu mol g(-1). The Fe3O4-R6G was successfully applied to the determination of Hg2+ in environmental samples, and could be used repeatedly by treatment with tetrabutylammonium hydroxide. (c) 2012 Elsevier B.V. All rights reserved.