In 1850 Runge use the process called “capillary analysis” for separating inorganic mixtures on various types of papers. However paper chromatography was not established until at late 1940s. In 1944 Congden, Gorden, Martin and Synge was able to separate amino acids by using papers. At present. paper chromatography is the method in which the analysis of an unknown substance is mainly done by the flow of solvents on specially designed filter paper. One of the two solvents is immiscible or partially miscible in the other solvent can be mixed. The solvent rises up by the capillary action and by adsorption on the paper the separation is affected by the differential migration of the mixture of substances. This occurs due to difference in partition co-efficient.
TYPES OF PAPER CHROMATOGRAPHY
Paper chromatography is a physiochemical separation method involving capillary ascent and can be classified into (1) Partition (2) Adsorption (3) Ion-exchange chromatography.
The standard method of analysis in which paper is used as an inter support with one-solvent as mobile phase and the other solvent as immobile phase is called paper partition chromatography.
In some cases paper is impregnated with as adsorbent like alumina or silica. The paper so modified, is used for the unknown components, this process is known as paper adsorption chromatography.
ION EXCHANGE CHROMATOGRAPHY
The ion exchange papers are tied for the separation of ionic species amino acids etc. Ion exchange papers are either modified forms of cellulose (acidic or basic groups) or a blend a cellulose with ion exchange resin. However, the resin-loaded types of paper is so widely available as that modified cellulose the apparatus and general method for ion exchange paper is same as for normal chromatography.