Synthesis, characterization, and analytical applications of erbium(III) ion imprinted polymer particles prepared via γ-irradiation with different functional and crosslinking monomers

Erbium(III) ion imprinted polymer (IIP) particles were synthesized by preparing erbium(III)-5,7-dichloroquinoline-8-ol-4-vinylpyridine prepolymer complex and then copolymerizing via γ-irradiation with different functional and crosslinking monomer combinations, viz. styrene-divinyl benzene, 2-hydroxyethyl methacrylate (HEMA)-ethylene glycoldimethacrylate (EGDMA), methyl methacrylate (MMA)-EGDMA. The erbium(III) imprint ion was removed by stirring the above particles with 6.0 mol l−1 HCl to obtain leached IIP particles. Control polymer (CP) particles were prepared without imprint ion. Again, CP, unleached and leached IIP particles were characterized by XRD, UV-vis spectrophotometric, pore size, SEM, and swelling ratio studies. The preconcentration of traces of erbium(III) during rebinding with leached IIP particles was studied as a function of pH, weight of polymer material, preconcentration and elution times, eluent concentration and volume, and aqueous phase volume. These studies indicate that as low as 2 μg of erbium(III) present in 500 ml can be preconcentrated into 20 ml of 1.0 mol l−1 HCl, and thus providing an enrichment factor of ∼25. Furthermore, the present study indicates that styrene-divinyl benzene-based IIP could be a better choice for the separation of erbium(III) from yttrium(III), dysprosium(III), holmium(III), and thulium(III) compared to HEMA-EGDMA and MMA-EGDMA-based IIPs.