Chromatography

Chromatography is a family of separation methods in which mixture components move differently because they interact unequally with a stationary phase and a moving phase.

Stationary phase: The phase that remains fixed in place during a chromatographic separation. Components separate because they spend different amounts of time interacting with this phase.
Partition coefficient: The equilibrium ratio describing how a substance distributes between two phases. Phase distribution helps determine how long a component is retained.
Gas chromatography: A chromatographic method that uses a gas as the mobile phase to separate volatile compounds. It applies the general method to volatile mixtures, often with a heated column.
Mikhail Tsvet: A Russian-Italian botanist who developed an early form of column chromatography in the early twentieth century. His plant-pigment experiments established the method's foundational example.
Electrophoresis: A separation method that moves charged particles through a medium under an electric field. It separates many biomolecules by electrical mobility rather than phase partitioning.
Mobile phase: The liquid or gas that moves through a chromatographic system and carries sample components. Its flow transports components past the stationary phase at different rates.
Adsorption: The accumulation of atoms, ions, or molecules at the surface of a material. Surface binding is the retention mechanism in adsorption chromatography.
High-performance liquid chromatography: A liquid chromatographic method that pumps solvent through a tightly packed column at high pressure. It enables efficient separations of compounds that are not readily analyzed as gases.
Plant pigment chromatography: The separation of plant pigments by passing extracts through an adsorbent material. Tsvet used this kind of separation to distinguish pigments in leaf extracts.
Distillation: A method that separates liquid mixtures through vaporization and condensation. It relies on volatility differences instead of differential movement through phases.

Linked from 38 pages