What Is the Process of Chromatography?

By Staff WriterLast Updated Apr 1, 2020 11:02:39 PM ET

The process of chromatography separates mixtures into their individual components. When divided using chromatography, each mixture has elements that separate into either a stationary phase or a mobile phase. In the stationary phase, components are solid or a liquid on a solid, such as a gel. In mobile phase, components are liquid or gases.

Chromatography is done by making the mobile components of a mixture move past the solids, or across the surface of a solid, like paper. The mixture is poured onto a solid surface. As the different components of the liquid run down the solid, some of them move more slowly than other. A component that moves slowly may spend more time in the solid phase than in liquid. One that moves more quickly may spend more time in liquid form than in solid. A base such as water may be added to the mixture to assist in the transition from solid to mobile phase. Because for chromatography to be effective the components of the mixture need to separate as much as possible, a large surface area is often needed for the mixture to be deposited on. The surface area should also be highly absorbent, created of something such as filter paper.