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

Abstract

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.