Paper chromatography is based on filter paper as an inert support. The filter paper fiber and water have strong affinity, can absorb about 22% of the water, and 6-7% of the water is in the form of hydrogen bonds with the cellulose hydroxyl group, under normal conditions is more difficult to remove, and filter paper fiber The affinity with organic solvents is very weak, so the general paper chromatography is actually based on the binding water of the filter paper fiber as the stationary phase and the organic solvent as the mobile phase. When the mobile phase passes through the sample along the paper, the solute on the sample point is in the water and The organic phase is continuously distributed. A portion of the sample moves with the mobile phase and enters the solute-free zone, where it is redistributed. A portion of the solute enters the stationary phase (aqueous phase) from the mobile phase. As the mobile phase continues to move, various parts are continuously distributed according to their respective distribution coefficients and move along the mobile phase, thereby allowing the substances to be separated and purified.

Filter Paper is a kind of filter tool commonly used in chemical laboratories. Its common shape is round, mostly made of cotton fibers.