Analysis of Sulfur Compounds in Natural Gas According to ASTM D5504

Significance of the topic

Reliable quantification of trace sulfur compounds in natural gas is critical for safety, environmental compliance and process optimization. Sulfur species such as hydrogen sulfide and mercaptans can contribute to corrosion, odor issues and catalyst poisoning. ASTM D5504 provides a standardized approach for accurate and reproducible analysis of multiple volatile sulfur compounds.

Objectives and overview of the application note

This application note demonstrates the use of the Shimadzu Nexis GC-2030 gas chromatograph equipped with a sulfur chemiluminescence detector (SCD-2030) and an SH-1 capillary column to analyze fourteen key sulfur components in natural gas. The method is validated against ASTM D5504 requirements.

Methodology

The sample introduction uses a 1 mL gas sampling loop and a 6-port switching valve. Helium serves as the carrier gas in constant column flow mode at 6.0 mL/min. Injection is performed via a split inlet (1:9 split ratio) at 150 °C. The SH-1 column (60 m × 0.53 mm I.D., 7 µm film) is maintained at 30 °C for 1.5 min, then ramped at 10 °C/min to 200 °C, held for 3 min.

Used Instrumentation

• Gas chromatograph: Shimadzu Nexis GC-2030
• Detector: SCD-2030 sulfur chemiluminescence detector
• Column: SH-1 capillary column, P/N 227-36108-02
• Valve: 6-port Restek sampling valve
• Carrier gas: Helium
• Gas flows for SCD: H₂ 100 mL/min, N₂ 10 mL/min, O₂ 12 mL/min, O₃ 25 mL/min

Main results and discussion

The system achieved baseline separation of fourteen target sulfur compounds, including hydrogen sulfide, carbonyl sulfide, various mercaptans and sulfides, carbon disulfide and thiophene. Retention times and peak shapes met ASTM D5504 criteria. The SCD provided low detection limits and high selectivity for sulfur species, demonstrating excellent signal‐to‐noise ratios even at sub‐ppm levels.

Benefits and practical applications of the method

• Comprehensive profiling of volatile sulfur compounds in natural gas streams.
• High sensitivity and selectivity using SCD technology.
• Reproducible retention times and quantitation in line with ASTM D5504.
• Robust performance for routine QA/QC and regulatory compliance.

Future trends and potential applications

Advances in detector technology and automated sampling could further lower detection limits and improve throughput. Integration with online sampling systems will enable real‐time monitoring of sulfur in gas pipelines and processing units. Coupling with chemometric tools may allow predictive maintenance and process optimization in petrochemical and energy sectors.

Conclusion

The Shimadzu Nexis GC-2030 with SCD-2030 and SH-1 column delivers a reliable, ASTM D5504–compliant method for the simultaneous analysis of a wide range of sulfur compounds in natural gas. Its sensitivity, selectivity and ease of operation make it suitable for both research laboratories and industrial QA/QC environments.

References

Application News G306 (Shimadzu Corporation, 2022)