Entrar

In certain chromatographic separations, solutes transfer between the mobile phase and the stationary phase via sorption, which typically refers to the process of adsorption. For many chromatographic systems, the sorption process often depends on the polarity of the compounds—an expression of the overall dipole moment within the molecule. During the separation process, there is competition between the solute and solvent for adsorption to the stationary phase. Highly polar compounds and solvents tend to adsorb strongly on polar surfaces, influencing their separation.

Several factors affect the distribution of the analyte, including column temperature and the characteristics of the stationary and mobile phases. The distribution constant for a given analyte is a key concept that expresses the ratio of the amount of the analyte adsorbed on or dissolved in the stationary phase to the amount of the analyte present in the mobile phase at a specific moment during the separation.

Commonly polar stationary phases, such as silica and alumina, are widely used in packed-column and planar chromatography. The solute's polarity determines the type of stationary phase and solvent. For example, highly active adsorbents may be utilized for weakly polar solutes, while more polar solvents can effectively carry polar compounds. The ability of the solvent to transport the analyte depends on its overall polarity, the nature of the solute, and the polarity of the stationary phase.

Do Capítulo 11:

article

Now Playing

11.3 : Analyte Adsorption and Distribution

Principles of Chromatography

413 Visualizações

article

11.1 : Chromatographic Methods: Terminology

Principles of Chromatography

577 Visualizações

article

11.2 : Chromatographic Methods: Classification

Principles of Chromatography

674 Visualizações

article

11.4 : Diffusion on Chromatography Columns

Principles of Chromatography

314 Visualizações

article

11.5 : Chromatographic Resolution

Principles of Chromatography

249 Visualizações

article

11.6 : Column Efficiency: Plate Theory

Principles of Chromatography

345 Visualizações

article

11.7 : Column Efficiency: Rate Theory

Principles of Chromatography

193 Visualizações

article

11.8 : Optimizing Chromatographic Separations

Principles of Chromatography

263 Visualizações

article

11.9 : Silica Gel Column Chromatography: Overview

Principles of Chromatography

733 Visualizações

article

11.10 : Thin-Layer Chromatography (TLC): Overview

Principles of Chromatography

772 Visualizações

article

11.11 : Gas Chromatography: Introduction

Principles of Chromatography

448 Visualizações

article

11.12 : Gas Chromatography: Types of Columns and Stationary Phases

Principles of Chromatography

322 Visualizações

article

11.13 : Gas Chromatography: Sample Injection Systems

Principles of Chromatography

272 Visualizações

article

11.14 : Gas Chromatography: Overview of Detectors

Principles of Chromatography

272 Visualizações

article

11.15 : Gas Chromatography: Types of Detectors-I

Principles of Chromatography

259 Visualizações

See More

JoVE Logo

Privacidade

Termos de uso

Políticas

Pesquisa

Educação

SOBRE A JoVE

Copyright © 2025 MyJoVE Corporation. Todos os direitos reservados