High-Sensitivity Simultaneous Analysis of Inorganic Gases and Light Hydrocarbons

Significance of the Topic

Detection of trace inorganic gases and light hydrocarbons is vital in environmental monitoring, industrial process control, and quality assurance.
Conventional methods require multiple detectors and complex flow configurations.
A unified analytical approach simplifies instrumentation and improves sensitivity.

Objectives and Overview

This study demonstrates the simultaneous, high-sensitivity analysis of inorganic gases (H2, O2, N2, CO, CO2, N2O) and C1–C2 hydrocarbons (CH4, C2H2, C2H4, C2H6) using a single gas chromatograph equipped with a barrier discharge ionization detector.
A standard gas mixture (5 ppm each component, helium balance) serves to evaluate performance metrics including sensitivity, repeatability, and simplicity of setup.

Methodology

A micropacked ST column was employed with a temperature program starting at 35°C (2.5 min), ramping to 250°C at 20°C/min, holding for 0 min, then to 270°C at 15°C/min over a total run time of 20 minutes.
Helium carrier gas was pressure-programmed from 250 kPa (2.5 min) to 400 kPa at 15 kPa/min.
Samples were introduced in split mode (1:5) with a 1 mL injection volume.
Detector parameters: BID discharge gas flow at 70 mL/min, detector temperature at 280°C, injection port at 150°C.

Used Instrumentation

• Gas chromatograph: Shimadzu Tracera (GC-2010 Plus A with BID-2010 Plus)
• Software: GCsolution
• Gas sampler: MGS-2010
• Column: Micropacked ST

Main Results and Discussion

The chromatogram of the 5 ppm standard showed baseline resolution and high sensitivity for all nine analytes in a single run.
Sequential analyses demonstrated excellent repeatability with relative standard deviations below 2% for all components.
Efficient separation was achieved without the need for additional methanizer or multiple detectors, confirming the capability of BID for detecting both inorganic gases and light hydrocarbons simultaneously.

Benefits and Practical Applications

• Reduced instrument complexity and lower operational costs by eliminating multiple detectors.
• High sensitivity and repeatability suitable for trace-level environmental and industrial monitoring.
• Streamlined workflow for QA/QC laboratories handling mixed gas samples.

Future Trends and Potential Applications

Advances in plasma-based ionization detectors may further enhance sensitivity and selectivity.
Integration with automated sampling systems could support real-time process monitoring and on-site environmental analysis.
Expansion to heavier hydrocarbons and additional inorganic species is anticipated, broadening the scope of simultaneous multi-gas analysis.

Conclusion

The Shimadzu Tracera GC with a barrier discharge ionization detector enables high-sensitivity, simultaneous analysis of a broad range of inorganic gases and light hydrocarbons in a simplified configuration.
The method delivers robust repeatability and operational efficiency, representing a valuable tool for diverse analytical applications.

References

Shimadzu Corporation. Tracera High-Sensitivity Gas Chromatograph System Data Sheet, First Edition: March 2013.