A fluorescent nitrate sensing system using a reaction cartridge and titanium trichloride

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Sensor Technology

Background:

• Accurate nitrate monitoring is crucial for water quality assessment.
• Existing methods for nitrate detection can be complex or lack sensitivity.

Purpose of the Study:

• To develop a simple, highly sensitive, and rapid cartridge-based sensing system for nitrate analysis.
• To utilize titanium trichloride for efficient nitrate reduction and fluorescence for ammonia detection.

Main Methods:

• Nitrate reduction to ammonium ion using titanium trichloride in hydrochloric acid within a cartridge.
• Flow injection analysis coupled with o-phthalaldehyde reaction for fluorescent isoindole formation.
• Detection of fluorescence for quantitative nitrate measurement.

Main Results:

• Achieved a detection limit of 0.01 mg l(-1) and a linear dynamic range from 0.05 to 2.5 mg l(-1).
• Demonstrated rapid response time (< 5 min) and high precision (RSD < 2.56% for > 30 measurements).
• Showed robustness against common interfering substances like FeCl(3), Na(2)SO(4), NaCl, and high BOD levels.

Conclusions:

• The developed cartridge sensing system provides a simple, sensitive, and rapid method for nitrate determination.
• The system is suitable for analyzing nitrate in environmental samples, such as river water.
• The method is robust and unaffected by common water matrix components.