Sample separation using chromatography is based on the use of two different phases:

  • Mobile phase: This is the phase the sample is mixed with. It allows the sample passing through the stationary phase and the whole system. Mobile phase normally defines the type of chromatography.

  • Stationary phase: This phase can be packed in a container called column, or be on a surface. This phase does not move, hence its name. Molecules with greater affinity to this phase will elute later.