What principle does gas chromatography utilize for separating compounds?

Gas chromatography separates compounds based on their boiling points, which is fundamental to the technique's operation. In gas chromatography, a volatile compound is vaporized and carried through a column by a flow of inert gas. As the mixture passes through the column, each component interacts differently with the stationary phase, which is often a viscous liquid coated on the interior of the column.

Compounds with lower boiling points tend to vaporize more readily and can travel through the column faster, while those with higher boiling points will interact more heavily with the stationary phase and take longer to elute from the column. This difference in retention times allows for the differentiation and separation of compounds within a mixture. Therefore, understanding the boiling point of the substances being analyzed is crucial for effective separation and identification in gas chromatography.