A new lead(II)-selective PVC-coated graphite rod electrode based on a Schiff base complex

Area of Science:

• Electrochemistry
• Analytical Chemistry
• Materials Science

Background:

• Lead(II) (Pb(II)) contamination poses significant environmental and health risks.
• Accurate and selective detection methods for Pb(II) are crucial for monitoring and remediation.
• Existing methods may have limitations in sensitivity, selectivity, or ease of use.

Purpose of the Study:

• To develop a new lead(II)-selective electrode.
• To characterize the performance of the electrode for Pb(II) detection.
• To evaluate the electrode's applicability in real-world sample analysis.

Main Methods:

• Fabrication of a lead(II)-selective electrode using a novel bis(acetylacetone)-p-phenylenediamine-lead(II) complex ionophore, dioctylphthalate (DOP) as a solvent mediator, and PVC as a matrix.
• Electrochemical characterization including Nernstian response, calibration slope, and detection limit determination.
• Selectivity testing against various cations and assessment of operational pH range.
• Application for direct determination of Pb(II) in environmental samples and comparison with Atomic Absorption Spectrometry (AAS).

Main Results:

• The developed electrode demonstrated a linear Nernstian response for Pb(II) from 1 x 10(-5) to 1 x 10(-1) mol L(-1).
• A cationic calibration slope of 30.0 ± 0.2 mV/concentration decade and a low detection limit of 2 x 10(-6) mol L(-1) (0.40 ppm) were achieved.
• The electrode exhibited fast response time, stable potential for 2 months, good selectivity for Pb(II) over other cations, and usability in the pH range of 4-8.
• Successful direct determination of Pb(II) in samples with results comparable to AAS, showing an average recovery of 96.5 ± 0.5%.

Conclusions:

• The novel lead(II)-selective electrode based on the [LPb(NO3)2]H2O complex ionophore is effective for sensitive and selective Pb(II) detection.
• The electrode offers advantages such as a wide linear range, low detection limit, fast response, and good stability.
• This sensor provides a reliable and cost-effective alternative for direct determination of lead in various sample matrices.