Liquid chromatography

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The liquid , in the default language and liquid chromatography (ger .: liquid chromatography abbreviated LC ) is a specialized field of chromatography is a physical separation method . A liquid serves as the mobile phase . It can either be in a column or a level. Modern methods are characterized by very small particle sizes and high inflow pressures.

One differentiates:

A distinction is made between open systems (e.g. thin-layer chromatography, paper chromatography), whereby the stationary phase can be removed and examined directly, and closed systems (e.g. column chromatography, HPLC). In closed systems, the substances are isolated after elution with a solvent or displayed with a detector.

Whether this separation method can be used to separate a substance mixture depends above all on whether all substances in the mixture can be dissolved in the mobile phase and whether there is a stationary phase that has sufficient selectivity between the substances. As a result of the elution or capillary action of the solvent, the stationary phase leads to a sorting process according to the molecular properties. The subsequent solvent creates substance zones that can be collected at the lower pipe outlet.

The stationary phases are often modified and unmodified silica gels (also called silica gels) and polymers , e.g. B. styrene-divinylbenzene copolymers (also polystyrene-divinylbenzene copolymers, PS / DVB) are used. In field-flow fractionation, various separating fields ( flow fields, thermal fields, etc.) are used as the stationary phase.

Individual evidence

  1. ↑ Entry on liquid chromatography (LC) . In: IUPAC Compendium of Chemical Terminology (the “Gold Book”) . doi : 10.1351 / goldbook.L03578 .

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