Analyze ppb Level Sulfur Compounds Using an Rt®-XLSulfur Micropacked GC Column or an Rtx®-1 Thick Film Capillary GC Column

Importance of the Topic

Sulfur compounds at ppb levels in petroleum streams can deactivate catalysts, cause equipment corrosion, and create environmental hazards due to toxicity and odor.
Accurate quantification is essential for process control and regulatory compliance.

Study Objectives and Overview

This article evaluates two GC column approaches for ppb level sulfur analysis in petroleum matrices:

• Thick-film capillary Rtx-1 column
• Rt-XLSulfur micropacked column

Methodology and Used Instrumentation

A comparison of chromatographic performance was conducted using:

• Rtx-1 capillary column (60 m × 0.53 mm, 7 μm and 30 m × 0.32 mm, 4 μm) with flame photometric detection
• Rt-XLSulfur micropacked column (various lengths, 0.75 mm ID) with sulfur chemiluminescence or combined SCD/FID detectors
• Sulfinert®-treated sample pathway components (cylinders, valves, loops, tubing) to ensure inertness

Main Results and Discussion

• Thick-film Rtx-1 resolves a wide range of sulfur species down to ~10 ppm with longer retention for heavier compounds.
• Rt-XLSulfur micropacked column achieves <10 ppb detection, rapid elution up to 310 °C, minimal bleed, and excellent inertness.
• Critical separation of H2S, COS, and SO2 meets ISBT Procedure 14.0 requirements.
• Effective resolution of sulfur compounds from C1–C6 hydrocarbons reduces analytical interferences.

Benefits and Practical Applications

• Enhanced catalyst protection and process safety through sensitive sulfur monitoring.
• Robust field and process control suitability owing to durable, inert sample pathways.
• Compliance with environmental standards by reliable low-level sulfur detection.

Future Trends and Applications

• Integration of fast GC techniques for higher throughput.
• Development of novel stationary phases to further improve selectivity and sensitivity.
• Automation and inline monitoring for real-time process analytics.

Conclusion

The combination of specialized columns and inert sample handling delivers reliable ppb-level sulfur analysis in petroleum streams, supporting both operational efficiency and environmental compliance.

References

• International Society of Beverage Technologists Procedure 14.0