Highly selective solid-phase extraction of trace Pd(II) by murexide functionalized halloysite nanotubes

Area of Science:

• Materials Science
• Analytical Chemistry
• Environmental Science

Background:

• Developing efficient adsorbents for trace metal separation is crucial for environmental monitoring and chemical analysis.
• Halloysite nanotubes (HNTs) offer a promising nanostructure for adsorbent modification due to their high surface area and tunable properties.

Purpose of the Study:

• To synthesize and characterize a novel murexide-modified halloysite nanotube adsorbent.
• To develop and optimize a solid phase extraction method for preconcentrating and separating palladium(II) ions.
• To evaluate the performance of the new adsorbent for trace palladium determination using ICP-OES.

Main Methods:

• Synthesis of murexide-modified HNTs.
• Characterization using FTIR, XRD, SEM, TEM, and BET analysis.
• Solid phase extraction (SPE) using a column procedure.
• Optimization of SPE parameters (pH, adsorbent amount, flow rate, elution conditions).
• Detection of Pd(II) using inductively coupled plasma-optical emission spectrometry (ICP-OES).

Main Results:

• The murexide-modified HNTs were successfully synthesized and characterized.
• Optimized SPE conditions achieved quantitative retention of Pd(II) at pH 1.0.
• An enrichment factor of 120 was obtained with a rapid analysis time of 5 minutes.
• The method demonstrated a low detection limit (0.29 ng mL⁻¹) and high adsorption capacity (42.86 mg g⁻¹).
• The method showed good selectivity, with no interference from common ions, and was validated with certified reference material.

Conclusions:

• Murexide-modified halloysite nanotubes represent a highly efficient adsorbent for solid phase extraction of Pd(II).
• The developed SPE-ICP-OES method is rapid, sensitive, and selective for trace palladium determination.
• This approach holds significant potential for analyzing palladium in environmental and industrial samples.