Mine Gas Analysis Using the Agilent 490 Micro GC

Significance of the Topic

The accurate analysis of mine gas components, particularly low-level carbon monoxide, is vital for the protection of mine workers and for monitoring underground air quality.

Study Objectives and Overview

This application note describes the use of the Agilent 490 Micro GC to perform rapid, multi-channel analysis of mine gas samples in under two minutes. The focus is on detecting permanent gases and C1-C2 hydrocarbons, with special attention to trace carbon monoxide in the presence of bulk methane.

Methodology and Instrumentation Used

The Agilent 490 Micro GC consists of three independent channels, each configured with a specific column and carrier gas:

• Channel 1: 10 m CP-Molsieve column, argon carrier, injector 50 °C, column 100 °C, static head pressure 150 kPa – measures H2, He, O2, N2
• Channel 2: 10 m CP-Molsieve column, helium carrier, injector 50 °C, column 70 °C, static head pressure 150 kPa, 5.65 s back-flush – optimized for low-level CO in methane with extra-high detector sensitivity
• Channel 3: 10 m PoraPLOT Q column, helium carrier, injector 50 °C, column 70 °C, static head pressure 150 kPa – quantifies CO2, ethylene, ethane

Main Results and Discussion

The system achieved baseline separations for permanent gases on channel 1. Oxygen, nitrogen, and CO quantification limits were 50–100 mg/L. Channel 2 enabled detection of CO at 2 mg/L within a methane matrix by combining back-flushing to eliminate methane tailing and extra-high sensitivity mode. Channel 3 provided clear resolution of CO2, ethylene, and ethane.

Benefits and Practical Applications

The Agilent 490 Micro GC delivers rapid, on-site measurement of critical mine gas species without extensive sample preparation. Its multi-channel design ensures comprehensive analysis within minutes, supporting real-time safety decision-making.

Future Trends and Potential Applications

• Integration with remote monitoring networks for continuous underground safety surveillance
• Expansion to additional volatile organic compounds and advanced detectors
• Miniaturization and automation for fully unattended operation in harsh environments

Conclusion

The Agilent 490 Micro GC demonstrates robust performance for mine gas analysis, achieving fast separation and sensitive detection of hazardous gases, particularly trace carbon monoxide in methane.

Reference

Brady D., Mine Gas Analysis Using the Agilent 490 Micro GC, Agilent Technologies Application Note, 2012.