Paper chromatography and chemical structure

Attempts to correlate the chromatographic behaviour of substances with their chemical structure must be based on accurate knowledge of R_F values and a survey of published work indicates that these may often be in error because of the practical difficulties of carrying out chromatography under ideal conditions. The theoretical limitations of chromatography in tanks are also discussed. In order to overcome certain of these difficulties, a new method for the accurate determination of R_F values, tankless or flat-bed chromatography, has been studied and its advantages examined. Chief among these are its extreme reproducibility, the possibility of running very large numbers of compounds together under near-ideal conditions and the precision of the experimental R_F values. A series of alkyl dinitrobenzoates was shown, by this method, to obey $\text{Martin}$'s equation with respect to ΔR_M(CH₂).