Protein Chemistry. Structure, Properties, Research Methods - Shendryk A.N. 2022

Methods for Experimental Investigation of Protein Structure
Chromatography

The Chromatography method was first proposed in the 19th century to study plant pigments (chroma), which is how it got its name. Today, this method is implemented in several variants (gas, gas-liquid, liquid chromatography, etc.).

All chromatographic Methods are based on a single principle: a continuous flow of a Mobile phase with the analyte dissolved in it passes through a stationary phase. Depending on its nature, the stationary phase interacts differently with individual Components of the sample mixture. As a result, the components are eluted and move relative to the stationary phase at different speeds.

Thus, chromatography is a process of separating mixtures of components based on differences in The values of their distribution constants between the mobile and stationary phases. The versatility of chromatography, regardless of its type, is due to the following main factors:

1. the presence of two phases (mobile and stationary);

2. the flow of the mobile phase relative to the stationary one ensures highly efficient mass transfer between them and the rapid establishment of local equilibria;

3. the components of the analyzed mixture must always be soluble in the mobile phase and have some affinity for the stationary phase, which ensures a specific distribution of components both between the phases and relative to the stationary phase;

4. a prerequisite for the successful Separation of a mixture into individual components is the difference in their equilibrium distribution constants.

Individual chromatographic methods differ in the type of interactions between the sample components and the stationary phase. These include Ion Exchange, solubility, adsorption or filtration, and sometimes a combination thereof.