gas chromatography, the separation and analysis of different substances according to their different affinities for a standard absorbent. In the process a gaseous mixture of the substances is passed through a glass cylinder containing the absorbent, which may be dampened with a nonvolatile liquid solvent for one or more of the gaseous components. As the mixture passes through the absorbent, each substance is absorbed to a different extent and leaves a characteristic pigment. The bands of different colors left when all the gaseous mixture has moved through the absorbent constitute a chromatograph for analysis. Compare column chromatography, ion exchange chromatography.
