Fluorometric fiber optic drop sensor for atmospheric hydrogen sulfide

Area of Science:

• Analytical Chemistry
• Environmental Science
• Sensor Technology

Background:

• Accurate measurement of atmospheric hydrogen sulfide (H2S) is crucial for environmental monitoring.
• Existing methods for H2S detection can be complex, expensive, or slow.
• There is a need for sensitive, real-time H2S monitoring techniques.

Purpose of the Study:

• To develop and validate a novel fluorometric technique for measuring low concentrations of atmospheric H2S.
• To utilize a renewable liquid drop sensor for enhanced H2S detection.
• To achieve simple, fast, and inexpensive near real-time H2S measurements.

Main Methods:

• A fluorometric technique employing a liquid drop of alkaline fluorescein mercuric acetate (FMA) solution.
• The FMA drop, suspended in an air stream, acts as a renewable sensor.
• Internal excitation by an optical fiber and fluorescence measurement by a photodiode.

Main Results:

• The reaction between H2S and FMA caused a significant, concentration-proportional decrease in fluorescence.
• Achieved limits of detection (LODs) in the double-digit parts per billion by volume (ppbv) range.
• Demonstrated a simple, fast, and inexpensive near real-time measurement with minimal reagent use.

Conclusions:

• The described fluorometric technique provides a highly selective and sensitive method for atmospheric H2S monitoring.
• This approach enables rapid, cost-effective H2S detection without extensive sampling.
• The liquid drop sensor offers a promising solution for real-time environmental H2S analysis.