Paper chromatography is an analytical method used to separate colored chemicals or substances. . A drop of mixture solution is spotted near one end of the paper and then dried. The end of the paper, nearest the spot, is then dipped into the solvent without submerging the spot itself. Paper chromatography is used to study the process of fermentation and ripening, to check the purity of pharmaceuticals, to detect the contaminants in drinks and foods, to examine the reaction mixtures in biochemical laboratories, determine dopes and drugs in humans and animals.