Chromatography is an analytical chemistry technique used to separate a blend of substances into their constituents. The fundamental principle of all forms of chromatography is that the mobile phase carries the constituents of the analyte through the stationary phase by capillary action. Various compounds travel at varying rates. The rate of migration relies on the strength of the chemical interactions between the analyte and the mobile phase as well as the interactions between the analyte and the stationary phase. Paper chromatography uses homogeneous porous paper as the stationary phase (David and Underwood 209). The mobile phase is usually an appropriate solvent or a blend of several solvents. The proportion of the distance covered by the substance to the distance traveled by the solvent is what is referred to as the ratio-to-front (Rf) value. The Rf value is constant for a specific compound provided all other factors (such as solvent components and paper type) are kept constant.