A highly selective thallium(I) electrode based on a thia substituted macrocyclic ionophore.

Area of Science:

• Analytical Chemistry
• Electrochemistry
• Sensor Technology

Background:

• Thallium(I) ions pose significant environmental and health risks.
• Accurate and selective detection methods for Tl(I) are crucial for monitoring and remediation.
• Existing methods may lack selectivity or require complex sample preparation.

Purpose of the Study:

• To develop a highly selective PVC membrane electrode for the detection of thallium(I) ions.
• To characterize the electrode's performance in terms of sensitivity, selectivity, and operational range.
• To evaluate the electrode's applicability in potentiometric titrations.

Main Methods:

• Fabrication of a PVC membrane electrode incorporating a tetrathia macrocycle (Bz(2)O(4)(16)aneS(4)) as the ionophore.
• Optimization of membrane composition using o-nitrophenyloctyl ether (o-NPOE) and potassium tetrakis(p-chlorophenyl)borate (KTpClPB).
• Electrochemical characterization using potentiometry to determine Nernstian response, detection limit, and selectivity.

Main Results:

• The developed electrode exhibited a Nernstian response to Tl(I) over a wide concentration range (1.0x10(-1)-2.23x10(-6)M) with a slope of 58.2mV/decade.
• A low detection limit of 1.58x10(-6)M and rapid response time (12s) were achieved.
• The electrode demonstrated excellent selectivity against various interfering cations and stable performance over a broad pH range (3.2-11.5).

Conclusions:

• The novel tetrathia macrocycle-based PVC membrane electrode provides a sensitive and selective method for Tl(I) detection.
• The sensor is robust, exhibiting good reproducibility and long-term stability (4 months).
• The electrode is suitable for direct potentiometric measurements and as an indicator in titrations, offering a practical tool for Tl(I) analysis.