RF Value in Chromatography

RF value is the degree of retention of a component retardation factor. RF value does not have units since the both lower and upper cases are in distance. Here the distance is measured up to the center of the spot.

RF value = (Distance traveled by the component) / (Distance traveled by the mobile phase)

The mobile phase travels up to the level of solvent front. We must carefully observe whether the mobile phase develops over the level of solvent front.  RF indicates the relative rate of movement of a solute and the solvent. RF value is a characteristic for a given substance under given conditions.