Chromium(III) ion selective electrode based on glyoxal bis(2-hydroxyanil)

Area of Science:

• Analytical Chemistry
• Electrochemistry
• Materials Science

Background:

• Chromium(III) is an essential trace element but can be toxic at higher concentrations.
• Accurate determination of Cr(III) is crucial for environmental monitoring and food safety.
• Development of selective and sensitive electrodes is vital for efficient Cr(III) analysis.

Purpose of the Study:

• To develop a novel poly(vinyl chloride) membrane electrode for selective Cr(III) ion detection.
• To characterize the electrode's performance, including its dynamic range, sensitivity, and response time.
• To evaluate the electrode's applicability in real-world sample analysis, such as food materials and alloys.

Main Methods:

• Fabrication of a poly(vinyl chloride) membrane incorporating glyoxal bis(2-hydroxyanil) as the ionophore.
• Electrochemical characterization using potentiometric measurements to determine selectivity and performance parameters.
• Testing the electrode's response across various concentrations, pH levels, and in the presence of interfering ions.
• Application of the developed electrode for Cr(III) determination in complex matrices like food samples and metal alloys.

Main Results:

• The Cr(III)-selective electrode exhibited a linear dynamic range from 3.0x10⁻⁶ to 1.0x10⁻² mol L⁻¹.
• A Nernstian slope of 19.8±0.5 mV per decade and a detection limit of 6.3x10⁻⁷ mol L⁻¹ were achieved.
• The electrode demonstrated a fast response time (<20 s), operational stability for over 3 months, and good selectivity for Cr(III) over other metal ions within a pH range of 2.7–6.5.

Conclusions:

• The developed glyoxal bis(2-hydroxyanil)-based poly(vinyl chloride) membrane electrode is a highly selective and sensitive sensor for Cr(III) ions.
• The electrode's robust performance and successful application in food and alloy analysis highlight its practical utility.
• This sensor offers a reliable and efficient method for the determination of chromium(III) in various industrial and environmental samples.