THE identification of non-volatile organic acids on paper chromatograms is usually dependent on the use of a suitable pH indicator which is applied to the developed and dried paper by spraying 1.

As the solvent soaks up the paper, it carries the mixtures with it. Different components of the mixture will move at different rates. This separates the mixture out.

Other than in the choice of medium, there is little difference between the techniques described here and those commonly used in paper chromatography.