Preparation and modification of macroporous epoxy-triethylenetetramine resin for preconcentration and removal of Hg(II) in aqueous solution

A novel macroporous resin was prepared from epoxy resin and triethylenetetramine through a polymerization with phase separation. In this experiment, the polyethylene glycol (PEG-1000) plays a very important part. It was used as solvent, as phase-separation reagent in the preparation processes, and as the pore-forming reagent through removing PEG-1000 from polymer by water-cleaning process after completing polymerization. The prepared resin was modified by carbon bisulfide and. soaked in 1 mol L-1 NaOH. Its structure was characterized by Fourier transform-infrared spectra, scanning electron microscopy, and elemental analysis. The adsorption characteristic of the chelating resin was studied by series of experiments. The results show that the chelating resin possesses excellent adsorption characteristic toward trace Hg(II). The recovery can come to 100% when the concentration of Hg(II) is only 0.05 ppm, and the average maximum adsorption capacity of the chelating resin for Hg(II) is 122 mg g(-1). The precision (relative standard deviation) for six replicate adsorbent extraction of 0.01 mu g mL(-1) Hg(II) was 1.1%. The accuracy of the proposed procedure was verified by analyzing a standard reference material. Moreover, the chelating resin was applied to two natural samples and also got satisfactory results. That is to say, the chelating resin modified by carbon bisulfide exhibits a high chelating ability toward Hg(II) and can be used as adsorbent for preconcentration and removal of trace Hg(II) in aqueous solution. (c) 2006 Wiley Periodicals, Inc.