Page 119 - phytochemistry general program

Another advantage of partition chromatography is that it is a very gentle .3
technique. Samples are rarely altered during the course of separation, because
inert support materials are used in conjunction with nonreactive partitioning

systems.

Types of chromatographic phases

Normal phase chromatography:
The support is loaded with a polar stationary phase, while a relatively non-polar

solvent(s) is used as the mobile phase.
Useful for separation of very or moderately non-polar compounds
Examples of stationary phases: water film in filter paper (partition), activated silica

gel (adsorption)

Reversed-phase chromatography:
Less polar stationary phase, and a polar moving phase.

Useful for separation of very polar compounds
Examples of stationary phases: kieselguhr impregnated with chloroform or liquid

paraffin (partition), alkyl silica bonded phase ex: C-18 (adsorption).
Techniques of partition chromatography

Examples of some techniques of partition chromatography are
- Column chromatography.
- Paper chromatography.

- Thin-layer chromatography.
- Counter-current chromatography. e.g. DCCC.

- Gas liquid chromatography (GLC)

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