Gas Chromatography Sampling

Gas chromatography (GC) is a powerful analytical tool that enables the simultaneous quantification of many stable species, including O₂, N₂, H₂, alkanes, alkenes, and aromatics.

In the Hanson Group, GC analysis is used in shock tube experiments to measure species yields after the reacting gas has been quenched by an expansion fan; gas samples are extracted through the shock tube endwall and subsequently analyzed. GC sampling measurements complement time-resolved laser absorption measurements by increasing the number of species that can be quantified simultaneously and enabling measurement of species that are difficult to measure optically (e.g., H₂).

This technique has been used to gain insight into the thermal cracking patterns of ethylene [1] and the wide array of intermediate species produced in low-temperature n-heptane oxidation [2]. The detailed speciation measurements enabled by GC sampling contribute to the development of more accurate chemical kinetic models, which in turn enable the design of next-generation energy systems.

graph of measuring ethylene, acetylene, and more against temperatures — Ultimate GC-measured ethylene, acetylene, hydrogen, and methane (x10) mole fraction results plotted against the initial T5 for a 1% ethylene/argon test gas mixture at approximately 5 atm [1].

To learn more, check out some of our publications:

[1] A. M. Ferris, D. F. Davidson, and R. K. Hanson, “A combined laser absorption and gas chromatography sampling diagnostic for speciation in a shock tube,” Combustion and Flame, Vol 195 (2018) pp. 40–49. DOI: 10.1016/j.combustflame.2018.04.032

[2] A. M. Ferris, J. W. Streicher, A. J. Susa, D. F. Davidson, and R. K. Hanson, “A comparative laser absorption and gas chromatography study of low-temperature n-heptane oxidation intermediates,” Proceedings of the Combustion Institute, Vol 37, Issue 1 (2019) pp. 249–257. DOI: 10.1016/j.proci.2018.05.018