Original form of chromatography:

Following the discovery of original form of chromatography, several new advances were made in the form of ion exchange chromatography, partition chromatography and gas chromatography. A logic of naming Tswett technique as chromatography does not carry good today since most of the compounds separated by this technique are not colored. The name is extremely well built and is not likely to change. Not only this, several other methods leading to the redistribution of components of a mixture are involved under the head chromatography.

The most important advances in chromatography were introduced by James and Martin. The impact of chromatography has been very great on all the areas of analysis and on the general progress of science. Recognition of this fact resulted in the award of Nobel Prize in 1952 to Martin and Synge for their pioneering work in this field.

As has already been mentioned, we see chromatography in its different forms. A general definition of chromatography covering its various forms is as given under:

Chromatography is a method of separation in which the components to be separated are distributed between two phases, one of these is called the stationary phase and the other the mobile phase which moves on the stationary phase in a definite direction. The stationary phase may be a solid or liquid and the moving phase may be liquid, gas or supercritical fluid. The components of a mixture redistribute themselves between two phases mainly by the process which might be adsorption, partition and ion exchange or size exclusion. For the reasons of simplification, in our elaborate here, on the categorization of separation methods, we will not involve supercritical fluid as one of the mobile phases. Therefore, this will be taken up later.