Support Gases?

[kankyo]

We usually call hydrogen and air as support gases depending upon the detector e.g. FID. If helium is the carries gas, what are the specific roles played by the support gases in the GC system? Thanks in advance for the replies

[chromatographer1]

Additional gases used other than the carrier gas in gas chromatography are generally used either for detectors or for mechanical valve operation. They can also be used to purge connections which might leak atmospheric gases into the analytical stream and interfer with trace gas measurements (Helium Ionization Detector, for example).

Flame Ionization Detectors require a flame, that is a fuel, and an oxidizer.

FPD also require a flame. A review of different detectors and the details of how they operate might be helpful in understanding the purpose of each gas choice.

A simple Google search for GC Detectors should be profitable for you.

best wishes,

Rod