Selective solid-phase extraction of nickel(II) using a surface-imprinted silica gel sorbent

Area of Science:

• Analytical Chemistry
• Materials Science
• Environmental Science

Background:

• Accurate determination of trace nickel (Ni(II)) is crucial for environmental monitoring and human health.
• Existing methods for nickel preconcentration often lack selectivity and efficiency.
• Surface imprinting techniques offer a promising approach for developing selective adsorbents.

Purpose of the Study:

• To develop a highly selective and efficient sorbent for the solid-phase extraction (SPE) of trace Ni(II).
• To prepare a novel Ni(II)-imprinted amino-functionalized silica gel sorbent.
• To determine trace Ni(II) in water samples using SPE coupled with inductively coupled plasma atomic emission spectrometry (ICP-AES).

Main Methods:

• Preparation of Ni(II)-imprinted amino-functionalized silica gel via a one-step surface imprinting technique.
• Selective solid-phase extraction (SPE) of trace Ni(II) from water samples.
• Determination of Ni(II) using inductively coupled plasma atomic emission spectrometry (ICP-AES).
• Evaluation of selectivity and adsorption capacity using various metal ions (Cu(II), Co(II), Zn(II), Pd(II)).

Main Results:

• The ion-imprinted polymers (IIPs) exhibited significantly higher selectivity and adsorption capacity for Ni(II) compared to non-imprinted polymers.
• Maximum static adsorption capacity for Ni(II) was 12.61 mg g(-1) for the imprinted sorbent.
• High selectivity factors (alpha(r) > 1) and distribution ratios (D) for Ni(II) over other metal ions were achieved.
• A low detection limit of 0.16 ng mL(-1) and good reproducibility (RSD = 1.48%) were obtained.
• The method demonstrated good agreement with certified reference materials and was successfully applied to real samples.

Conclusions:

• The developed Ni(II)-imprinted amino-functionalized silica gel sorbent provides excellent selectivity and adsorption capacity for trace nickel.
• The SPE-ICP-AES method is sensitive, selective, and reliable for determining trace Ni(II) in environmental and biological samples.
• This approach offers an effective solution for preconcentration and determination of nickel in complex matrices.