A small subsurface ion mobility spectrometer sensor for detecting environmental soil-gas contaminants

Area of Science:

• Environmental Science
• Analytical Chemistry
• Spectrometry

Background:

• Volatile organic compounds (VOCs) pose environmental risks.
• Monitoring soil gas in the vadose zone is crucial for site assessment.
• Existing methods for VOC detection can be complex or costly.

Purpose of the Study:

• To assess the potential of a small subsurface ion mobility spectrometer (SS-IMS) for monitoring gaseous VOCs.
• To determine the feasibility of using IMS for real-time analysis of environmental contaminants in the vadose zone.

Main Methods:

• A small subsurface ion mobility spectrometer (SS-IMS) was constructed.
• The SS-IMS was tested using various environmental contaminants, including trichloroethylene (TCE) and tetrachloroethylene (PCE).
• Detection limits and reduced mobility (K(0)) values were determined for 11 contaminants.

Main Results:

• Trichloroethylene (TCE) and tetrachloroethylene (PCE) were successfully detected and separated using IMS.
• Detection limits as low as 1 part per billion by volume (ppb(v)) were achieved.
• Reduced mobility (K(0)) values were reported for 11 environmental contaminants.

Conclusions:

• Ion mobility spectrometry is a viable technology for detecting and separating soil-gas contaminants.
• The developed SS-IMS offers a practical and simple approach for field monitoring.
• This technology has the potential for long-term monitoring of contaminated soils.