Principles and Applications of Partition Chromatography
Partition chromatography utilizes the difference in solubility of the components to be separated between the stationary phase and the mobile phase to effect separation. The stationary phase for partitioning the chromatogram is generally a solvent in the liquid phase, which is distributed on the column or the surface of the support by means of a pattern, bonding, adsorption, or the like. The process of partitioning the chromatogram is essentially the process by which the constituent molecules continue to reach a dissolved equilibrium between the stationary phase and the mobile phase.
The carrier for liquid-liquid partition chromatography mainly includes silica gel, diatomaceous earth, and cellulose. Generally, when a water-soluble component or a relatively polar component is separated into a compound such as an alkaloid, a glycoside, a saccharide or an organic acid, a strong polar solvent such as water, a buffer solution or the like is used for the stationary phase, and weaker polar organic solvent such as chloroform-ethyl acetate or butanol are used for the mobile phase, so it is called normal phase chromatography; however, when separating a fat-soluble compound, such as a higher fatty acid, a fat or a free steroid, the two phases can be reversed, and the stationary phase can be used Paraffin oil, while the mobile phase is a strong polar solvent such as water or methanol, so it is called reversed phase partition chromatography.