Measurement/data-processing method to improve the ruggedness of membrane-based sensors: Application to amperometric...

Area of Science:

• Analytical Chemistry
• Electrochemistry
• Sensor Technology

Background:

• Membrane-based oxygen sensors are crucial for various applications.
• Traditional methods can be affected by experimental variables, impacting result accuracy.
• Existing steady-state approaches have limitations in sensitivity and stability.

Purpose of the Study:

• To introduce and evaluate alternative measurement and data-processing approaches for membrane-based oxygen sensors.
• To reduce the impact of experimental variables on oxygen sensor measurements.
• To enhance the precision and reliability of oxygen concentration determination.

Main Methods:

• Developed pre-equilibrium measurement techniques involving sensor equilibration before applying a polarizing voltage.
• Utilized current vs. time data during response decay towards a steady-state condition.
• Implemented fixed-time and integration data-processing options to quantify oxygen within the membrane.

Main Results:

• Linear relationships observed between measured current/total charge and oxygen concentration (0.05–0.26 mmol l⁻¹).
• Pooled relative standard deviations near 0.4% for new methods, comparable to 0.3% for steady-state.
• Pre-equilibrium options demonstrated significantly reduced dependencies on membrane thickness and stirring rate (over two orders of magnitude smaller).

Conclusions:

• Alternative pre-equilibrium measurement and data-processing methods offer improved accuracy and stability for oxygen sensors.
• The new approaches effectively minimize the influence of experimental variables like membrane thickness and stirring rate.
• These advancements provide a more robust and reliable method for oxygen concentration analysis.