Multiple Pulse Amperometry-An Antifouling Approach for Nitrite Determination Using Carbon Fiber Microelectrodes

Area of Science:

• Analytical Chemistry
• Environmental Science

Background:

• Nitrite is a widespread environmental pollutant requiring accurate detection methods.
• Bare electrodes suffer from poisoning and passivation, limiting their use in electroanalytical applications.
• Carbon fiber microelectrodes offer potential but require strategies to overcome inherent limitations.

Purpose of the Study:

• To develop a robust electroanalytical method for nitrite determination.
• To enhance the stability and performance of carbon fiber microelectrodes.
• To mitigate electrode deactivation during nitrite sensing.

Main Methods:

• Utilized pulsed amperometry, specifically a three-pulse approach, on carbon fiber microelectrodes.
• Investigated the effect of pulsed potential on current decay compared to constant potential.
• Assessed the repeatability and reproducibility of the developed method.

Main Results:

• Reduced current decay from 47% to virtually 0% over 20 minutes using the three-pulse amperometry technique.
• Achieved excellent repeatability (RSD < 0.5%) and good reproducibility (RSD < 7%).
• Demonstrated accurate nitrite quantification in fortified tap water and synthetic saliva samples.

Conclusions:

• The proposed three-pulse amperometry method effectively overcomes limitations of bare electrodes for nitrite sensing.
• This approach significantly improves the stability and reliability of electroanalytical determination of nitrite.
• The method shows promise for practical applications in environmental monitoring and analysis.