Rapid determination of trace level copper in tea infusion samples by solid contact ion selective electrode

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Materials Science

Background:

• Development of ion-selective electrodes (ISEs) is crucial for accurate chemical analysis.
• Solid contact electrodes offer advantages in robustness, cost, and speed over traditional designs.
• Copper ion detection is important in environmental monitoring and industrial processes.

Purpose of the Study:

• To prepare and characterize a novel solid-contact copper(II) ion-selective electrode.
• To evaluate the electrode's performance, including response time, selectivity, and stability.
• To demonstrate the electrode's applicability in real-world sample analysis.

Main Methods:

• Fabrication of a poly(vinyl chloride) (PVC) membrane electrode using o-xylylenebis(N,N-diisobutyldithiocarbamate) as the ionophore.
• Incorporation of solid contacts to enhance electrode robustness and reduce cost.
• Potentiometric measurements to determine the electrode's response characteristics and selectivity.
• Application in potentiometric titration and direct assay of tea infusion samples.

Main Results:

• The developed electrode exhibited a rapid (<10 seconds) and near-Nernstian response to Cu²⁺ activity over a wide concentration range (10^-1 to 10^-6 mol/L).
• The electrode operated effectively within a pH range of 4.0-6.0 with no significant interference from common ions.
• High potential stability, reproducibility, and repeatability were observed.
• Accurate determination of copper(II) ions in tea infusion samples was achieved, with results comparable to atomic absorption spectroscopy (AAS).

Conclusions:

• The novel solid-contact copper ion-selective electrode demonstrates excellent performance characteristics.
• The electrode's robustness, fast response, and cost-effectiveness make it a promising alternative for copper ion analysis.
• The successful application in real samples validates its practical utility in potentiometric analysis.