Define Gas liquid chromatography?

This is used for separating and identifying volatile compounds of fatty acids, hydrocarbons, sterols, amino acids and lipids, even from nanogram quantities of a sample. Since volatility is an essential criterion for this method, the compounds should be non-polar or made non-polar through chemical derivatization.

The vapourized mixture of volatile compounds are carried by an inert gas like helium (He), argon (Ar) or nitrogen (N₂) (mobile phase) through a long hot tube containing a column of inert fibre brick or diatomaceous earth particles impregnated with a non-volatile liquid like silicone oil, grease (stationary phase). The volatile components separate from each other according to their partition coefficients between the mobile gaseous phase and the stationary liquid phase. As the compounds leave the column they pass through a detector which is linked viz. an amplifier to a chart recorder which in turn records a peak.