A novel phosphate detection sensor: From FTIR to EC-QCL.

Area of Science:

• Environmental Science
• Analytical Chemistry
• Spectroscopy

Background:

• Phosphorus pollution from sewage poses significant environmental risks.
• Conventional infrared spectroscopy methods for pollutant detection have limitations.
• External cavity quantum cascade laser (EC-QCL) spectroscopy presents a promising alternative technology.

Purpose of the Study:

• To develop and validate a novel transmission detection system for phosphate concentration in water bodies.
• To utilize an EC-QCL-based system for enhanced pollutant detection.
• To explore the feasibility of miniaturized, in-situ sewage detection sensors.

Main Methods:

• Implementation of a long optical path transmission detection system utilizing an EC-QCL.
• Development of linear regression models for phosphate concentration analysis.
• Comparison of models based on raw radiation intensity versus traditional absorbance data.

Main Results:

• Linear regression models demonstrated high accuracy with determination coefficients > 0.98.
• The system achieved a minimum detection limit below 5.1 ppm for phosphate.
• EC-QCL's high spectral density enabled direct analysis using raw intensity data, yielding comparable results to absorbance methods.

Conclusions:

• The proposed EC-QCL detection system provides accurate and reliable phosphate detection in water.
• The miniaturization potential of the EC-QCL system offers a novel approach for developing portable, in-situ sewage monitoring sensors.
• This technology addresses the critical need for effective environmental pollutant detection.