Filter paper fiber and water have strong affinity, can absorb about 22% of the water, and with 6 ~ 7% of the water in the form of hydrogen bonding with cellulose hydroxy, difficult to take off under general conditions, and the filter paper fibers and the affinity of organic solvents is very weak, so the general paper chromatography, in fact, with the combined water of filter paper fiber as the stationary phase, with organic solvent as mobile phase, when flow down paper after the sample, the sample point between solute in water and organic phase in the continuous distribution, part of the sample with the mobile phase, into the area of the solute, at this time and redistribution, part of the solute from the mobile phase to stationary phase (water).
