Читать книгу Chemical Analysis - Francis Rouessac - Страница 45

Halfway between chromatography and extraction, this technique, though not often employed for analytical purposes, is used as a purification method in biochemistry. It consists of preparing a stationary phase (carrier resin) on which a specific ligand for the molecule we wish to separate is grafted to a maximum number of sites. As it has affinity for the ligand, the molecule is retained on the column. After elution of the other compounds present with the binding liquid phase, the latter is transformed into an elution buffer to retrieve the molecule of interest. The yield of this operation is related to the number of sites available on the resin, and the selectivity of the separation depends on the choice of ligand, which must be pure.