On-site Analysis of Volatile Organic Compounds in Soil and Air with E²M

Significance of the topic

The assessment of volatile organic compounds (VOCs) in soil and air is critical for evaluating environmental pollution from industrial sites. Rapid on-site analysis enables timely decision-making, risk assessment, and remediation planning, reducing delays and costs associated with conventional laboratory methods.

Study objectives and overview

This application note demonstrates the use of the mobile GC/MS system E²M equipped with a thermodesorption (TD) module for fast, on-site measurement of VOCs in soil air and chemical dump air. The study aims to map contamination distributions and quantify key halogenated compounds within minutes.

Methodology and used instrumentation

Sampling

• Soil and dump air collected by drawing defined volumes through TENAX® adsorption tubes using hand-held or electric pumps.
• Samples taken directly from boreholes or dump covers to capture headspace air.

Thermodesorption-GC/MS Conditions

• Instrument: Mobile E²M GC/MS system in TD mode
• Column: 15 m DB-1, 0.32 mm ID, 5 μm film
• Desorption: Stand-by at 45 °C; ramp to 240 °C for 30 s; charge at 600 mbar for 10 s
• GC Temperature Program: 45 °C → 120 °C at 10 °C/min → 180 °C at 20 °C/min → 220 °C at 35 °C/min (hold 100 s)
• Carrier Gas: Ambient air at 1.5 mL/min
• MS Scan Range: 46–350 u; 5 ms/mass integration

Results and discussion

Soil Air Analysis

• Trichloroethylene detected at 12.9 mg/m³ (RT 365 s)
• Tetrachloroethylene detected at 240 mg/m³ (RT 610 s)

Dump Air Analysis

• Major VOCs identified include toluene (0.7 mg/m³), carbon disulfide, tetrahydrofuran, tetrachloroethylene, ethylbenzene, xylene isomers, chlorinated benzenes, and naphthalene.

The total analysis time per sample is 10–15 minutes, achieving low-ppb detection limits. Chromatograms and mass spectra confirm reliable compound identification via NIST library matching.

Benefits and practical applications

• On-site operation reduces sample transport and laboratory turnaround times.
• Low operational complexity allows non-specialists to perform analyses.
• Cost-effective mapping of contamination across large areas (thousands of m²) within days.
• Supports rapid environmental risk assessment and remediation strategies.

Future trends and opportunities

Advances may include integration of automated sampling routines, wireless data transfer, and real-time geospatial mapping. Expansion to semivolatile or emerging pollutant classes and coupling with AI-driven data analysis could further enhance environmental monitoring capabilities.

Conclusion

The mobile E²M GC/MS platform with thermodesorption offers a powerful tool for rapid, on-site VOC analysis in soil and air. It delivers accurate quantification and identification within minutes, streamlining environmental investigations and supporting timely remediation decisions.

Reference

Bruker Daltonics Application Note MS-12, "On-site Analysis of Volatile Organic Compounds in Soil and Air with E²M," September 2008