SYNTHESIS AND CHARACTERISTICS OF A CHELATING RESIN AS AN EXTRACTANT AND CHROMOGENIC REAGENT OF HEAVY METAL IONS IN SOLID PHASE EXTRACTION

A new chelating resin （CPS-DMA-SABA） was synthesized with the chloromethylated crossqinked polystyrene porous beads （CPS） as raw materials, which were bonded with salicylidene-o-aminobenzoic acid （SABA） on the surface via a quaternary ammonium unit as a linker. The results showed that CPS-DMA-SABA would easily change into a zwitterionic chelating resin （CPS-DMA-SABZ） when washed with distilled water. CPS-DMA-SABA was characterized by elemental analysis, infrared spectra and thermo-gravimetric analysis. The ion sorption capacities of CPS-DMA-SABA were found to be 1916 μg/g for Zn2＋ withpH at 4.5, 1620μg/g for Cu2＋ with pH at 6.2, 1291 μg/g for Ni2＋ withpH at 6.6 and 780 μg/g for Cr3＋ withpH at 5.5, respectively. The experiments showed CPS-DMA-SABA also changed its color when meeting with the metal ion in the aqueous solution. As a consequence, CPS-DMA-SABA can not only be used as a solid phase extractant but also an indicator for confirming the heavy metal ion in solutions.