A process used for separating mixtures by virtue of differences in absorbency WordNet 3.0 & Open English WordNet

In chemical analysis, chromatography is a laboratory technique for the separation of a mixture into its components. Wikipedia

Set of laboratory techniques for the separation of mixtures Wikidata

A method of separating and analyzing mixtures of chemical substances by selective adsorption in a column of powder or on a strip of paper. OmegaWiki

Any of various techniques for the qualitative or quantitative separation of the components of mixtures of compounds; all characterised by the use of a mobile phase (gas or liquid) moving relative to a stationary phase (liquid or solid) - the differences between the rates of migration of the compounds between the two phases effects the separation. Wiktionary

Analytical chemistry: technique for separation of components in a mixture. Wiktionary (translation)