Types and Functions of Chromatography Reagents

Stationary phase: The stationary phase is the part of the column that provides a surface with which the components in the sample can interact. The stationary phase can be a solid (e.g. silica gel, alumina) or a liquid (coated on a solid carrier), or it can be a gel or other porous material.
Mobile phase: The mobile phase is the liquid or gas that carries the sample through the column. In high performance liquid chromatography (HPLC), the mobile phase is usually a mixture of water and organic solvents (such as methanol, acetonitrile) whose polarity and composition can be adjusted for analytical purposes.
Eluent: Eluent is a part of the mobile phase used to eluate and separate the sample components from the stationary phase. The choice of eluent is very important to the effect of chromatographic separation.
Detection agents: In some chromatographic methods, such as thin layer chromatography (TLC), specific detection agents are required to visualize chromatographic spots. These detection agents are usually chemicals that react color with the components of the sample.
Derivatization reagents: Derivatization reagents are used to convert certain components of a sample (e.g. amino acids, sugars) into more detectable forms for chromatographic analysis.
Buffers: In ion exchange chromatography (IEC) and other chromatographic methods that require pH control, buffers are used to maintain the pH stability of the mobile phase, which affects the separation of sample components.