Synthesis of a new resin functionalized with xanthine moiety and its application for separation of nickel and cadmium in natural water

A new chelating resin has been synthesized by functionalization of polystyrene-divinylbenzene (8%) with xanthine through -N=N- bonding. The resulting resin has been characterized by elemental analysis, thermogravimetric analysis, infrared spectroscopy, hydrogen ion capacity and capacity of metal ions. The separation and mesurement of Ni(II) and Cd(II) were carried out with this resin and the maximum exchange capacity of Cd(II) was found to be 0.73 mmol g-1 and that for Ni(II) was 0.57 mmol g-1 at pH 1.0 for both. The eluents 10% thiourea in 0.1 M HC104 and 1.0 M sulphosalicylic acid have been used for separation of Cd(II) and Ni(II), respectively. The detection limits for Ni(II) and Cd(II) were found to be 3.6 and 4.1 ng mL-1, respectively . The optimum flow rate and sample breakthrough volume of column operation for both the metal ions were found to be 1.2 mL min-1 and 3000 mL, respectively. The developed method was applied for determination of these two metal ions in synthetic binary mixtures. The developed method was also applied to natural water sample and compared with the results of previously developed method.