What information can be gained from running a gas chromatogram?

Chromatography is an analytical technique that is used to separate the components of a mixture between two states (a stationary and a mobile one).

In chromatography of gases, the mobile phase is gas while the stationary phase is liquid or solid on solid support.

The information that can be gained from running a gas chromatogram is:
1- The retention time
2- The proportion of the components found in the sample 

Gas chromatography is a common type of chromatography used with analytical chemistry for separating and even analyzing compounds for uses. This is helpful without having to decompose them, only vaporizing them and analyzing. It has practical uses, such as measuring toxins in compositions or isolating pure gases or compounds.