Selective Sorption of Noble Metals on Polymer Gel Modified with Ionic Liquid

Area of Science:

• Analytical Chemistry
• Materials Science

Background:

• Precious metal analysis requires selective and efficient extraction methods.
• Ionic liquid-modified materials offer unique properties for solid-phase extraction.

Purpose of the Study:

• To investigate the solid-phase extraction of Au, Ir, Pd, Pt, and Rh using a methylimidazolium-based ionic liquid polymer gel (MIA-PG).
• To develop and validate analytical procedures for determining these precious metals in environmental and geological samples.

Main Methods:

• Solid-phase extraction using MIA-PG sorbent.
• Optimization of extraction conditions (HCl concentration).
• Adsorption studies using Langmuir and Freundlich models.
• Kinetic analysis (pseudo-second-order model, intraparticle diffusion, ion exchange).
• Development and validation of analytical methods for Pd, Pt, Rh, and Au.

Main Results:

• MIA-PG exhibited high sorption (>95%) for Au, Ir, Pd, and Pt at 0.05 M HCl, with 65% for Rh.
• Negligible retention of base metals (Cu, Fe, Ni, Zn, Mn).
• Complete elution achieved using thiourea in HCl.
• Adsorption followed pseudo-second-order kinetics, with intraparticle diffusion and ion exchange as rate-limiting steps.
• Validated analytical procedures for Pd, Pt, Rh in dust/soil and Au in copper ore/concentrate.

Conclusions:

• MIA-PG is a highly selective and effective sorbent for precious metal extraction.
• The developed analytical methods are suitable for routine laboratory applications.
• The study provides a robust method for precious metal determination in complex matrices.