Synthesis, characterization and application of ion imprinted polymeric nanobeads for highly selective preconcentration and spectrophotometric determination of Ni²⁺ ion in water samples.

Here, the researchers report on the synthesis of ion imprinted polymeric (IIP) nanoparticles using a thermal polymerization strategy, and their usage for the separation of Ni(2+) ion from water samples. The prepared Ni-IIP was characterized by colorimetry, FT-IR spectroscopy, and scanning electron microscopy. It was found that the particle size of the prepared particle to be 50-70 nm in diameter with the highly selective binding capability for Ni(2+) ion, with reasonable adsorption and desorption process. After preconcentration, bound ions can be eluted with an aqueous solution of hydrochloric acid, after their complexation with dimethylglyoxime, these ions can be quantified by UV-Vis absorption spectrophotometry. The effect of various parameters on the extraction efficiency including pH of sample solution, adsorption and leaching times, initial sample volume, concentration and volume of eluent were investigated. In selectivity study, it was found that imprinting causes increased affinity of the prepared IIP toward Ni(2+) ion over other ions such as Na(+), K(+), Ag(+), Co(2+), Cu(2+), Cd(2+), Hg(2+), Pb(2+), Zn(2+), Mn(2+), Mg(2+), Cr(3+), and Fe(3+). The prepared IIP can be used and regenerated for at least eight times without any significant decrease in binding affinities. The prepared IIP is considered to be promising and selective sorbent for solid-phase extraction and preconcentration of Ni(2+) ion from different water samples.