Chromatography is a physical method used to separate, identify, and purify the components of a mixture for qualitative and quantitative analysis. The process involves passing a liquid or gaseous solvent (the mobile phase) through a system, e.g., a capillary tube, a sheet, or a plate, in which a substitute part of the mixture becomes fixed (the stationary phase). The separation is generally achieved because of the hydrophilic or lipophilic properties of the various components.

Though chromatography is used as a general term, there are numerous specific techniques: column chromatography, thin-layer chromatography, and paper chromatography being amongst the most popular.