EXERCISE 4: CHROMATOGRAPHY

• • Chromatography - is a separation technique used to separate different compounds from a mixture based on the distribution of components between a stationary phase and a mobile phase.
• • Stationary phase - is the immobile component that provides the surface for interaction with the sample components.
• • Mobile phase - is the moving component that carries the sample through the stationary phase.
• • Adsorption chromatography - separation is governed by surface adsorption phenomena.
• • Partition chromatography - separation occurs due to differences in solubility of the sample in the stationary and mobile phases.
• Thin layer chromatography (TLC) - a form of adsorption chromatography that uses a thin layer of adsorbent such as alumina or silica gel attached on a flat surface, usually glass.
• • Paper chromatography - a form of liquid-liquid partition chromatography that uses a solvent as the mobile phase that moves the paper strip up by capillary action.
• solid alumina or silica gel attached on a flat surface such as glass - Stationary phase of adsorption chromatography (TLC)
• Stationary phase of Partition chromatography - liquid supported on the surface of the mobile phase
• Stationary phase of Paper chromatography - filter paper
• Mobile phase of Adsorption chromatography (TLC) - liquid that flows over the stationary phase, carrying the sample with it.
• Mobile phase of Partition chromatography - liquid or gas that is insoluble in the stationary phase.
• Mobile phase of Paper chromatography - solvent that moves up the paper strip by capillary action, carrying the sample with it.