Column chromatography

Column chromatography separates mixture components as a mobile phase carries them through a column of stationary material. Components travel at different rates because they interact differently with the stationary and mobile phases.

Stationary phase: The phase that remains fixed while another phase moves past it during a separation. Its surface or pore structure selectively retains components as they pass through the column.
Partition coefficient: The ratio describing how a solute distributes between two phases at equilibrium. Different phase distributions produce different migration rates in partition-based columns.
Flash chromatography: A preparative column chromatography method that uses pressurized gas to drive solvent through a packed column. It speeds up silica-column separations for purification in synthetic chemistry.
Thin-layer chromatography: A planar chromatography method in which solvent carries a sample across a coated plate. It uses similar phase interactions but separates spots on a flat surface rather than in a packed tube.
Mobile phase: The fluid that moves through a separation system and carries sample components. Its composition controls how strongly components remain dissolved and how quickly they elute.
Polarity: The uneven distribution of electrical charge within a molecule or chemical bond. Molecular polarity helps predict affinity for polar stationary phases and solvents.
Size-exclusion chromatography: A method that separates molecules by their access to pores in a stationary material. It uses columns to fractionate polymers and biomolecules mainly by size.
Paper chromatography: A planar method that separates substances as solvent moves through paper by capillary action. It offers a simple paper-based alternative to packing a column.
Adsorption chromatography: Chromatography in which components separate through differing adsorption onto a solid stationary phase. This is the retention mechanism in columns packed with adsorbents such as silica or alumina.
Silica gel: A porous, amorphous form of silicon dioxide used as an adsorbent and support material. Its polar surface makes it a common stationary phase for organic mixtures.

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Arne TiseliusCompared with: Column methods physically recover fractions, whereas moving-boundary electrophoresis primarily analyzes them in solution.