Sulfur gases and hydrocarbons, C1 – C3 - Analysis of sulfur and hydrocarbons by GC-AED

Importance of the Topic

Volatile sulfur gases and low molecular weight hydrocarbons are key analytes in energy production and petrochemical industries. Accurate detection and quantification improve environmental monitoring, safety protocols and product quality control.

Study Objectives and Overview

This application note describes a gas chromatographic method combined with atomic emission detection for simultaneous analysis of C1 to C3 hydrocarbons and sulfur gases such as carbonyl sulfide and hydrogen sulfide. The aim is to achieve baseline separation and reliable quantification without interferences or detector quenching effects.

Methodology and Instrumentation

The method employs a capillary GC system with a PLOT silica column under a temperature program from 40 C to 250 C. Helium serves as the carrier gas. A split injection yields a 1 mL sample introduction and detection is performed by an atomic emission detector using separate carbon and sulfur channels.

Used Instrumentation

• Gas chromatograph with capillary inlet and split injection
• Agilent CP Silica PLOT column 0.32 mm by 30 m, film thickness 4 µm
• Helium carrier gas at 210 kPa (2.1 bar)
• Atomic emission detector with carbon channel (C 193) and sulfur channel (S 181)

Main Results and Discussion

The method achieves clear separation of methane, carbon monoxide, ethylene, acetylene, propane, propylene and carbon dioxide from sulfur gases. Carbonyl sulfide and hydrogen sulfide elute without interference and are quantified at 50 ppm levels. Hydrocarbons are monitored at concentrations up to 500 ppm. Dual detection channels prevent quenching and ensure selective measurement.

Benefits and Practical Applications

• Simultaneous analysis reduces total analysis time and sample consumption
• Universal atomic emission detection enhances sensitivity for hydrocarbons
• Dedicated sulfur channel avoids detector quenching by sulfur compounds
• Suitable for process monitoring and quality control in petrochemical operations

Future Trends and Potential Applications

Advances may include coupling GC with mass spectrometry for compound confirmation, novel stationary phases for faster separations, and portable GC-AED systems for field deployment. Automated sampling and data processing will drive higher throughput and real-time monitoring capabilities.

Conclusion

This GC-AED method provides a robust and reliable approach for concurrent quantification of C1 to C3 hydrocarbons and trace sulfur gases. The technique supports industrial quality assurance, environmental compliance, and safety applications.

Reference

1. Agilent Technologies Inc Application Note A01292 Energy and Fuels October 2011
2. Courtesy Jim Luong The Dow Chemical Company Canada