Electrochemical dissolved oxygen removal from microfluidic streams for LOC sample pretreatment

Area of Science:

• Environmental Science
• Analytical Chemistry
• Electrochemistry

Background:

• Current water quality monitoring offers limited temporal and spatial data.
• Heavy metal detection sensors face challenges with in-field calibration and sample pretreatment.
• Dissolved oxygen (DO) interferes with electroanalytical techniques for certain metals.

Purpose of the Study:

• To design and evaluate a miniaturized, low-power device for in-line removal of dissolved oxygen (DO).
• To address limitations of existing portable DO removal methods for sensor applications.
• To enable calibration-free heavy metal monitoring in real-time.

Main Methods:

• Development of an indirect in-line electrochemical DO removal (EDOR) device.
• Utilizing a silver cathode and an oxygen-permeable membrane for passive DO diffusion.
• Detection of DO levels using cyclic voltammetry (CV) and amperometry in a thin-layer cell (TLC) detector.

Main Results:

• Achieved 98% DO removal from test samples.
• Operated effectively at flow rates up to 50 μL/min.
• Demonstrated low steady-state power consumption of 165 mW h L(-1).

Conclusions:

• The developed EDOR device offers a practical solution for miniaturized DO removal.
• This technology is suitable for long-term, real-time water quality monitoring sensors.
• The device is also applicable to microfluidic (LOC) systems requiring DO regulation.