A technique is described for the quantitative analysis of organic compounds by chromatography on narrow strips of glass plate bearing a thin layer of adsorbent. A relationship between the length, L, of the zone occupied by a compound, the weight, C, of compound applied and the distance, D, travelled by the developing solvent, viz., L= K log C log D(where K is a constant), has been found to hold under specified conditions and can be used to determine organic compounds alone or in admixture.