Optofluidic differential colorimetry for rapid nitrite determination

Area of Science:

• Analytical Chemistry
• Environmental Science
• Microfluidics

Background:

• Nitrite detection is crucial for environmental monitoring and industrial applications.
• Traditional colorimetric analysis for nitrites is time-consuming and cumbersome due to calibration curve requirements.
• Existing methods lack stability and anti-interference capabilities.

Purpose of the Study:

• To develop a novel differential colorimetry method for accurate nitrite quantification.
• To eliminate the need for calibration curves in nitrite detection.
• To enhance the stability and anti-interference performance of nitrite detection methods.

Main Methods:

• Utilized a microfluidic network to couple color reactions and generate paired chromaticity gradients.
• Developed a differential colorimetry approach analyzing the interaction of two chromaticity gradients.
• Implemented a self-correcting mechanism for improved accuracy and stability.

Main Results:

• Successfully quantified nitrite solutions (0.50 mM and 0.33 mM) with low errors (1.16% and 0.50%).
• Achieved up to 10 times greater stability and 6 times higher accuracy compared to calibration curve methods.
• Demonstrated high stability and anti-interference performance due to gradient independence and self-correction.

Conclusions:

• The differential colorimetry method offers a rapid, stable, and accurate approach for nitrite detection.
• This technique significantly reduces time and energy consumption by requiring only a single sample.
• The method shows potential for widespread application in chemical detection, particularly in environmental and industrial settings.