Synthesis of a new ion-imprinted polymer and its characterization for the selective extraction and determination of nickel ions in aqueous solutions

Abstract

A new ion-imprinted polymer (IIP) was synthesized by bulk polymerization from 2-vinylpyridine (the functional monomer), ethylene glycol dimethacrylate (EGDMA; the cross-linker), 2, 2′- azobisisobutyronitrile (the initiator), diphenylcarbazone (the ligand), and nickel nitrate (the template ion) in acetonitrile solution. The prepared IIP was characterized by Fourier transform infrared spectroscopy and scanning electron microscopy, and studied for the preconcentration and determination of trace nickel ion from aqueous solutions using inductive couple plasma optical emission spectroscopy. The optimal pH value for the quantitative preconcentration was 6.0 and maximum sorbent capacity was 3.26 mg g⁻¹. Under the optimized conditions, the method had a linear analytical range from 0.5 to 50 μg L⁻¹. The detection limit, relative standard deviation, and recovery of the method were evaluated as 0.38 μg L⁻¹, 3.6% and 95–98%, respectively. The developed method was successfully applied to the selective extraction and determination of trace nickel in synthetic and real water samples and some medicinal plants with satisfactory results.

Keywords:

• Ion-imprinted polymer
• Nickel
• Inductively coupled plasma optical emission spectrometry
• Extraction

Acknowledgments

The authors would like to acknowledge the financial assistance from Tehran University of Medical Sciences, Tehran, Iran. The authors thank the MOH and ME Laboratory Research Center and Institute of Medicinal Plants, ACECR, for the supply of some instruments.