THIN LAYER CHROMATOGRAPHY (TLC)
Thin-layer chromatography (TLC) is an altogether new, versatile and specialized laboratory technique that was evolved in early Fifties, and since then has become an indispensable means of separation for analysts and researchers round the globe. It can be employed conveniently both for organic and inorganic substances, either derived from natural sources or synthesized in the laboratories, on quantities ranging from the nanogram to microgram levels.
Kirchner in 1950 was the first who used adsorption chromatography on impregnated glass-plate coated with silicic acid or alumina. It may be emphasized, however, that Egon Stahl’s fundamental work stands as a landmark in the world-wide acceptance of this new technique in the laboratory. Later on, Stahl in 1958, introduced a standard equipment for preparing uniform thin-layers of known thickness, which eventually led to the ultimate acceptance of this new technique as an additional modern tool for analytical chemistry.
This is invariably referred to in various literature as : ‘open-column chromatography’; ‘drop chromatography’ ; ‘strip-chromatography’ ; ‘spread-layer chromatography’ ; ‘surface chromatography’.
TLC in addition to combining the meritorious plus points of column and paper chromatography, also considered to be extraordinarily superior to either of the two in certain aspects.