Evolution Of Chromatography:

There are a huge number of separation methods that vary in their utility in a particular situation. Several of these important methods fall under the category of chromatography. Thus, before we discuss classification of separation methods, it will be appropriate to give an idea of the chromatographic science. In Unit 4 of this course, a discussion on classification and general principles of chromatography has been presented. Subsequent this unit, some of the units discusses important chromatographic methods in detail. In sequence to keep the text of this particular unit properly jointed, a short idea about the evolution of chromatography is being presented here.

The subject of chromatography had a very modest beginning. The principles and the applications were reported in 1906 by a Russian botanist, Mikhail Tswett. He described the resolution of chlorophylls and other plant pigments in a plant extract. A petroleum ether solution of chlorophyll was passed through a calcium carbonate column. By passing the solvent through the column, the pigments were resolved into several zones. This separation became practical if after the pigment solution, the pure solvent was allowed to pass through the column. Such a preparation was termed as the chromatogram and the corresponding method, the chromatographic method. The term chromatography is derived from the Greek words chroma and graphy meaning colour writing. A discovery of chromatography was made along with the separation of coloured compounds but its potential for colourless compounds was realized. Tswett himself anticipated the potential of this technique for a wide variety of compounds. This technique is now termed as liquid-solid adsorption chromatography.