Читать книгу Chemical Analysis - Francis Rouessac - Страница 44

The stationary phase here is a material containing pores whose dimensions are selected as a function of the size of the species to be separated. This technique is used to separate synthetic or natural macromolecules. It is known as gel filtration (e.g. separation of natural macromolecules such as proteins) when the mobile phase is aqueous, or gel permeation (e.g. separation of synthetic macromolecules) when the mobile phase is an organic solvent. Thus, it involves a sort of selective permeation at the molecular scale. For this technique, the distribution coefficient is called the diffusion coefficient.