Selective solid-phase extraction of Ni(II) by an ion-imprinted polymer from water samples

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Accurate determination of trace nickel in water is crucial for environmental monitoring.
• Developing selective sorbent materials is key for efficient solid-phase extraction (SPE).

Purpose of the Study:

• To synthesize and characterize a novel ion-imprinted polymer (IIP) for selective nickel ion (Ni(II)) extraction.
• To evaluate the performance of the IIP in a solid-phase extraction method for trace nickel determination in water samples.

Main Methods:

• Synthesis of IIP via copolymerization using 4-vinylpyridine, ethyleneglycoldimethacrylate, and 2,2'-azobis-sobutyronitrile with a Ni-dithizone complex.
• Application of the IIP as a sorbent in a solid-phase extraction column.
• Optimization of SPE parameters including sample volume, elution conditions, pH, and flow rate.
• Determination of nickel using flame atomic absorption spectrometry (FAAS).

Main Results:

• The synthesized IIP demonstrated high selectivity for Ni(II) over other metal ions (Co(II), Cu(II), Cd(II)) with relative selectivity factors (αr) ranging from 21.6 to 54.3.
• The method achieved a low detection limit of 1.6 µg L⁻¹ for Ni(II) using 150 mL of sample.
• The relative standard deviation for replicate Ni(II) determinations was 3.4%.
• The developed SPE-IIP method was successfully applied to real water samples.

Conclusions:

• The developed ion-imprinted polymer is a highly selective and efficient sorbent for the solid-phase extraction of nickel ions.
• This method provides a sensitive and reliable approach for the determination of trace nickel in environmental water samples.