TABLE OF CONTENTS Chromatography can be defined as the separation of mixtures by distribution between two or more immiscible phases. Some of these immiscible phases can be gas liquid, gas solid, liquid liquid, liquid solid, gas liquid solid and liquid liquid solid. Strictly speaking, a simple liquid liquid extraction is in fact a chromatographic process. Similarly, distillation is a chromatographic process that involves separation of liquids by condensation of their respective vapours at different points in a column.
Most will remember the school science project of placing an ink blot in the centre of a filter paper and following this by dripping methylated spirits on to the ink. Watching in fascination as concentric circles of various pigments develop is probably the first and sometimes last experience of a chromatographic separation many will encounter. Like too many of our observations the essence of this experiment is to demonstrate that black ink is made up of several different pigments and the underlying process, in this case chromatography, is dismissed with blatant disregard.
Chromatography was originally developed to isolate coloured pigments from plants. Hence, from Greek origins we get chromato, colour and graph, to record .
Fortunately for us, some very clever scientists have seen the wood for the trees and have taken these simple observations and developed them into complex, highly efficient, methods of purification.
The invention of chromatography was rightly accredited to Mikhail Tswett in 1902 [1.1] for his detailed study of the selective adsorption of leaf pigments on various adsorbents, though somewhat unwittingly, the first demonstrations of preparative...
