RES-Q-Trace: A Mobile CEAS-Based Demonstrator for Multi-Component Trace Gas Detection in the MIR

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Environmental Science

Background:

• Sensitive trace gas detection is crucial for industrial process control, environmental monitoring, medical breath analysis, and security applications.
• Real-time, selective, and sensitive detection of trace gases presents significant challenges in these fields.

Purpose of the Study:

• To report on a compact and transportable multi-component system (RES-Q-Trace) for molecular trace gas detection.
• To demonstrate the system's capability using cavity-enhanced techniques in the mid-infrared (MIR).

Main Methods:

• The RES-Q-Trace system employs four independent continuous wave lasers coupled with optical cavities.
• Two cavity-enhanced absorption spectroscopy methods were utilized: off-axis cavity-enhanced absorption spectroscopy (OA-CEAS) and optical feedback cavity-enhanced absorption spectroscopy (OF-CEAS).
• Multi-functional software was developed for system control, laser driving, and signal analysis for concentration determination.

Main Results:

• The system successfully monitored relevant species such as NO, N₂O, CH₄, C₂H₄, and C₃H₆O in the MIR.
• Detection limits in the parts per billion (ppb) and parts per trillion (ppt) range were achieved at atmospheric pressure.
• The versatility and performance of the RES-Q-Trace instrument were validated for breath gas analysis and explosives detection.

Conclusions:

• The RES-Q-Trace system provides a compact, transportable solution for sensitive and selective trace gas detection.
• The demonstrated performance highlights its potential for real-time applications in medical diagnostics and security screening.