Chromium(III) ion-selective electrode based on 4-dimethylaminoazobenzene

Area of Science:

• Analytical Chemistry
• Electrochemistry
• Materials Science

Background:

• Accurate and selective detection of chromium(III) is crucial for environmental monitoring and industrial processes.
• Development of ion-selective electrodes (ISEs) offers a sensitive method for metal ion quantification.

Purpose of the Study:

• To develop and characterize a novel PVC-based membrane electrode for the potentiometric determination of chromium(III) ions.
• To evaluate the electrode's performance, including response range, pH independence, response time, reproducibility, and selectivity.

Main Methods:

• Fabrication of a PVC-based membrane incorporating 4-dimethylaminoazobenzene as an ionophore.
• Potentiometric measurements to assess the electrode's response to varying concentrations of chromium(III).
• Evaluation of operational parameters such as pH range, response time, and selectivity against common interfering ions.

Main Results:

• The electrode exhibited a Nernstian response for Cr(III) over a wide concentration range (1.66 x 10⁻⁶–1.0 x 10⁻² mol dm⁻³).
• A stable potential was observed in the pH range of 3.0–5.5, with a fast response time of approximately 10 seconds.
• The sensor demonstrated good reproducibility over 3 months, a detection limit of 8 x 10⁻⁷ M, and high selectivity for Cr(III).

Conclusions:

• The developed 4-dimethylaminoazobenzene-based PVC membrane electrode is a highly selective and sensitive sensor for chromium(III) determination.
• The electrode's performance characteristics make it suitable for direct potentiometric analysis and as an indicator electrode in titrations.
• This sensor offers a reliable and cost-effective alternative for chromium(III) monitoring.