In particular paper chromoatography is an ideal technique for the separation of compounds present in a small mixture. The extract (mixture) of the plant to be analysed is placed as a spot on a filter paper and dipped in a suitable solvent. The solvent travels on the paper due to capillary action and carries with it the different substances in the extract.
The rate of migration of the different substances depends upon their solubility and specific gravity. The filter paper (chromatogram) should be removed from the solvent before it reaches the edge of the paper and dried. By spraying a suitable reagent (for eg.g ninhydrin for amino acids) the compounds can be detected as several spots widely separated on the paper.