Why not use oxygen gas in gas chromatography?

Answer 1

Most gas chromatography column stationary phases are based on modified polysiloxane or polyethylene glycol materials. These materials oxidize in the presence of oxygen at elevated temperatures. This behavior, known in part as bleed, will very quickly degrade the performance of the column.

Absolutely!

Also, you want a non-reactive (inert) carrier gas, one that will not react with your sample. Oxygen is a powerful oxidizer. It will change the structure (oxidize) of species in your sample. Then you will not be able to detect the compound of interest but only its oxidation products.

For example: if you are trying to determine blood alcohol level you don't want the alcohol to be oxidized because then you will get a blood alcohol level that is lower than the true level.

Answer 2

Oxygen is a reactive element and can react with substances to be analyzed.