Optimisation of Electrokinetic Extraction System: Colourimetric Determination of Copper (II) in Sand Using Polymer...

Area of Science:

• Analytical Chemistry
• Environmental Science
• Materials Science

Background:

• Solid matrices like sand often require complex pretreatment for metal ion analysis.
• Existing methods for copper extraction can be time-consuming and less efficient.
• Colorimetric detection offers a sensitive yet accessible analytical approach.

Purpose of the Study:

• To develop and optimize an electrokinetic extraction (EKE) system coupled with polymer inclusion membranes (PIMs) for copper ion (Cu(II)) determination in sand.
• To improve the quantification range and recovery efficiency of Cu(II) extraction.
• To enable direct colorimetric analysis of Cu(II) in solid samples without pretreatment.

Main Methods:

• Electrokinetic extraction (EKE) utilizing a formic acid gel and a sample compartment.
• Incorporation of polymer inclusion membranes (PIMs) containing 1-(2-pyridylazo)-2-naphthol (PAN) for Cu(II) complexation and colorimetric detection.
• Optimization of EKE system parameters, including column diameter and PIM composition (CTA, D2EHPA, PAN).

Main Results:

• Optimized system achieved a quantification range of 2.8-30.0 mg kg⁻¹ for Cu(II) in sand.
• Increased column diameter from 4.5 mm to 13.5 mm extended the upper quantification limit from 7.5 to 30.0 mg kg⁻¹.
• Optimized PIM composition enhanced Cu(II) recovery from 64% ± 7% to 90% ± 4%, with LOD of 0.9 mg kg⁻¹ and LOQ of 2.8 mg kg⁻¹.

Conclusions:

• The optimized EKE-PIM system provides a sensitive, efficient, and direct method for Cu(II) extraction and colorimetric quantification from sand.
• The developed method eliminates the need for sample pretreatment, simplifying the analytical process.
• This approach holds promise for the environmental monitoring of heavy metals in solid matrices.