Measuring absolute gas amounts with gas chromatography by using a novel setup for pressure based gas control

Area of Science:

• Analytical Chemistry
• Chemical Engineering
• Materials Science

Background:

• Gas properties like volatility and compressibility complicate accurate gas feeding into measurement systems.
• Traditional gas injection methods, such as syringes, suffer from issues like gas tightness and volume inaccuracies, especially for small gas quantities.

Purpose of the Study:

• To develop a novel, reliable, and contaminant-free gas injection system for analytical instruments.
• To overcome the limitations of existing gas injection techniques for precise gas quantification.

Main Methods:

• Development of a gas injection system comprising an injection unit, vacuum system, and loop assembly.
• Direct connection of the system to gas chromatography (GC) instruments and other gas-related devices.
• Validation through diverse configurations, extensive testing, and application demonstrations.

Main Results:

• The system provides reliable, contaminant-free gas introduction into analytical devices.
• Demonstrated applications include contamination-free gas supply from battery pouch-bag cells and analysis of thermal decomposition products.
• Reduced pressure operation enables multi-point calibration with single gas mixtures and quantitative concentration calculations with <10-20% error.

Conclusions:

• The developed system is a versatile, platform-independent solution for introducing gas into low-pressure environments without contamination.
• Integrated loop technology facilitates accurate quantitative analysis of gas concentrations.
• The system enhances precision in gas analysis, particularly for challenging samples like flexible pouch cells.