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How does paper chromatography use capillary action to move a solvent?
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chromatography
Overview of the chemical technique of chromatography.
In paper chromatography, capillary action is the physical mechanism that drives the movement of the mobile phase through the stationary phase.12
The process functions as follows:
- Setup: A sheet or strip of filter paper acts as the stationary phase. A sample is applied as a spot near one edge of the paper.12
- Immersion: This edge of the paper is placed into a shallow reservoir containing a liquid solvent, which serves as the mobile phase.13
- Capillary Movement: Driven by capillary action, the solvent is drawn upward through the porous structure of the paper, moving perpendicular to the surface of the liquid reservoir.23
- Separation: As the solvent front travels up the paper, it passes over the sample spot, dissolving the components and carrying them along. The components migrate at different velocities based on their relative solubilities in the stationary and mobile phases, resulting in their separation on the paper.13