How does gas chromatography separate the components of a gaseous mixture?

In gas chromatography, a gaseous mixture is separated by transporting it through a column using an inert carrier gas (the mobile phase), such as helium or argon.12

The separation process relies on the varying degrees of interaction between the mixture's components and a stationary phase—typically a solid or a liquid film coated on a solid support—packed inside the column. As the sample travels through the column, components distribute themselves between the mobile and stationary phases based on their relative affinities.13

Substances with a stronger attraction to the stationary phase are retarded and move more slowly, while those with weaker interactions are flushed through the column more rapidly. Because each component travels at a different velocity, they emerge from the column at distinct times, where they are identified by a detector. This technique effectively exploits differences in polarity and volatility to resolve complex mixtures into individual components.132