Agilent 990 Micro GC J&W CP-Sil 19 CB Channels

Significance of the Topic

Natural gas quality assurance demands accurate detection of odorants like tetrahydrothiophene (THT). Micro GC offers rapid on-site analysis and high selectivity for trace-level components. This ensures pipeline safety, regulatory compliance, and process optimization.

Objectives and Overview

This summary reviews the Agilent 990 Micro GC equipped with J&W CP-Sil 19 CB columns. It highlights channel configurations, performance metrics, and suitability for natural gas odorant analysis.

Methodology and Used Instrumentation

• Instrument: Agilent 990 Micro GC with up to four MEMS-based analytical channels.
• Injectors: Micromachined, no moving parts, programmable injection volume (1–10 µL), heated to 110 °C.
• Columns: J&W CP-Sil 19 CB phases in lengths of 6 or 12 m, straight or backflush configurations, medium polarity tailored for THT separation.
• Detectors: Micromachined thermal conductivity detectors (TCD), dual-channel reference/sample, four filaments, 200 nL cell volume.
• Carrier gases: He, H₂, N₂, or Ar at 550 ± 10 kPa; hydrogen restricted on mobile systems.

Main Results and Discussion

• Resolution: Straight 6 m column achieves 1.5 iC₄/nC₄ separation; 12 m with backflush achieves 2.5.
• Detection Limits: THT detection down to 0.3–0.6 ppm, depending on channel tuning.
• Repeatability: Peak area RSD below 0.5 % for most channels; THT-specific channel shows <10 % RSD at low ppm levels.
• Temperature: Isothermal operation up to 180 °C ensures rapid cycle times and stable baselines.
• Backflush: Removes heavy components post-run, maintaining column integrity and shortening analysis time.

Benefits and Practical Applications

• Selective THT separation from complex natural gas matrices at trace concentrations.
• Compact design permits field deployment for on-line monitoring or mobile laboratories.
• Multi-channel flexibility allows simultaneous analysis of different compound classes.
• Reduced maintenance via MEMS technology and backflush functionality.

Future Trends and Applications

• Integration with digital data platforms for real-time remote monitoring and predictive maintenance.
• Expanded column chemistries for multi-residue environmental or petrochemical screening.
• Improved detectors with lower limits of detection and enhanced compound identification.
• Automation of calibration and method transfer procedures to support decentralized analysis.

Conclusion

The Agilent 990 Micro GC with J&W CP-Sil 19 CB channels delivers rapid, reliable, and sensitive measurement of natural gas odorants. Its modularity and robust design cater to both laboratory and field applications, ensuring quality control and regulatory compliance.

References

• Agilent Technologies Inc. Data Sheet 5994-7605EN, July 2024.