Quantitation of Methane Dissolved in Hexanes, Toluene and Water - No.351

Importance of the Topic

Quantifying dissolved hydrogen in hydrocarbons and water is essential for process control in chemical manufacturing, quality assurance in fuel and lubricant industries, and safety monitoring in environmental and research laboratories. Reliable detection of hydrogen at trace levels helps prevent unwanted reactions, ensures product integrity, and supports compliance with regulatory standards.

Objectives and Overview

This application note presents a gas chromatography method using a barrier discharge ionization detector to accurately measure dissolved hydrogen in hexane, toluene and water. The aim is to establish analytical conditions that deliver precise quantitation across common solvent matrices, leveraging an SH-Msieve 5A column for effective separation of hydrogen from other components.

Methodology

Samples were introduced via split injection at a 1:5 ratio with a 0.5 µL volume. Helium served as the carrier gas under constant linear velocity to optimize chromatographic resolution. The column temperature was maintained at 40 °C to facilitate the selective elution of hydrogen. Detector parameters were set to maximize ionization efficiency and signal stability for hydrogen measurement.

Used Instrumentation

• Gas chromatograph: Nexis GC-2030 with AOC-20i Plus autosampler
• Column: SH-Msieve 5A, 30 m × 0.53 mm I.D., 50 µm film thickness, with 2.5 m particle trap
• Detector: BID-2030 barrier discharge ionization detector

Main Results and Discussion

The method achieved baseline separation of hydrogen from solvent and water peaks. Calibration exhibited excellent linearity over the targeted concentration range, with limits of detection and quantitation in the low micromolar domain. The barrier discharge detector provided consistent baseline stability and reproducible response across multiple injections, demonstrating robustness of the approach.

Benefits and Practical Applications

• High sensitivity measurement of dissolved hydrogen in diverse solvent systems
• Rapid analysis with minimal sample preparation requirements
• Robust and reproducible performance for routine quality control and safety assessments

Future Trends and Possibilities

Advancements may include fully automated sampling workflows, expansion to additional solvent and aqueous matrices, and integration with orthogonal detectors for simultaneous multi-analyte profiling. Development of portable GC-BID platforms could enable on-site dissolved gas monitoring in field and industrial environments.

Conclusion

The described GC-BID method paired with an SH-Msieve 5A column provides a sensitive, accurate, and reproducible solution for quantifying dissolved hydrogen in hexane, toluene, and water. Its straightforward setup and reliable performance make it well suited for industrial quality control, process monitoring, and environmental analysis.

Reference

• Application News G335 JP ENG, Shimadzu Corporation, First Edition Sep 2022, ERAS-1000-0351