Generally, chromatography techniques can be divided into two large classes. Depending on the mobile phase, different classes of chromatography can be distinguished:
Gas chromatography: the mobile phase is a gas, such as Helium.
Liquid chromatography: the mobile phase is a liquid, such as PBS.
The stationary phase could be either liquid or solid in both classes.
Chromatography can be further divided into four categories based on the mechanism of interaction between the sample mixture and the stationary phase, as shown in table 1. These categories are adsorption, partition, ion exchange, and permeation.
There are two types of stationary phase support: column and planar layer. In column chromatography, the stationary phase is packed into a column and the mobile phase flows through. In planar layer chromatography, the stationary phase is on a flat plate or in the pores of paper, and the mobile phase moves by capillary action.
Table 1 - Different chromatographic techniques.
Links to chromatographic techniques: