The synthesis and characterization of new adsorbents is addressed in this work. This material is based on the coupling of magnetic nanoparticles and graphene oxide (MNPs@GO). Graphene oxide (GO) presents a high surface area to volume ratio, and high rate of diffusion in water. However it is tedious and difficult to separate GO from the aqueous solution. The coupling with magnetic nanoparticles provides an easy magnetic separation. Thus, MNPs@GO has demonstrated to be an excellent adsorbent material towards to organic compounds but not to ionic metals. For this reason, a chelating group is attached to the material surface: [1,5-bis(2-pyridyl)-3-methylene] thiocarbonohydrazide (DPTH) in order to increase the selectivity for metal ions. To establish which is the best route of synthesis, two different strategies were designed (method 1 and method 2). The two new materials obtained, called DPTH(1) and DPTH(2), were characterized and their properties as extractants were studied. Several analytical techniques were used to characterize them; TEM, XPS, CNHS elemental analysis and FT IR. To conclude, the DPTH(2) showed better properties as extractant, even at trace levels.
Keywords: Solid-phase extraction, magnetic nanoparticles, graphene oxide, chelating functional groups, TEM, XPS, IR