1. A method of finding out which components a gaseous or liquid mixture contains that involves passing it through or over something that absorbs the different components at different rates: Chromatography involves the mixture of materials to be separated and percolated through a column or sheet of some suitable chosen absorbent; for example, an ion-exchange material; the substances least absorbed are least retarded and emerge the earliest; those more strongly absorbed emerge later.
2. The separation of chemical substances and particles; originally plant pigments and other highly colored compounds by differential movement through a two-phase system.