Chromatographic method:

i)          Gas-liquid chromatography

When the two phases are gas and solid, a few examples of the methods are as given below:

1.         Non-chromatographic methods

i)           Sublimation

ii)        Adsorption

2.         Chromatographic methods

i)          Gas-solid chromatography

ii)        Exclusion chromatography

In the case of sublimation, the solid is directly vaporised and the equilibrium exists among the gas and the solid. Adsorption of gases through solids is a well known technique of separation and that forms the basis of gas-solid chromatography. The exclusion of molecules based on shape and size of both gas and liquid can take place.