What are the two phases in chromatography?

What are the two phases in chromatography?

• A. Stationary phase and mobile phase.
• B. Liquid and gas.
• C. Solvent and solute.
• D. Solid and liquid.

Answer: (A)

Chromatography hinges on two phases: a stationary phase that stays fixed in place, and a mobile phase that flows through or over it. The sample components separate because they distribute between these two phases unevenly. If a component interacts strongly with the stationary phase, it spends more time there and moves through the system more slowly, leading to longer retention. If it prefers the mobile phase, it travels with the moving solvent and elutes faster. This concept applies across methods: in gas chromatography the mobile phase is an inert carrier gas while the stationary phase is a liquid film on a solid support; in liquid chromatography the mobile phase is a liquid solvent and the stationary phase can be solid or a bonded liquid. The key idea is the differential partitioning or adsorption between these two phases that drives separation.

Chromatography hinges on two phases: a stationary phase that stays fixed in place, and a mobile phase that flows through or over it. The sample components separate because they distribute between these two phases unevenly. If a component interacts strongly with the stationary phase, it spends more time there and moves through the system more slowly, leading to longer retention. If it prefers the mobile phase, it travels with the moving solvent and elutes faster.

This concept applies across methods: in gas chromatography the mobile phase is an inert carrier gas while the stationary phase is a liquid film on a solid support; in liquid chromatography the mobile phase is a liquid solvent and the stationary phase can be solid or a bonded liquid. The key idea is the differential partitioning or adsorption between these two phases that drives separation.