Topics - Thin Layer Chromatography (TLC)

Thin Layer Chromatography (TLC) Conventional chromatography is carried out in a tubular distribution system (usually called the chromatographic column) where the stationary phase is held on a support packed inside the column, or adheres to the walls of a tube. The mobile phase flows through the packing, or past the film of stationary on the column walls to develop the separation. Thin layer chromatography (TLC) is also a separation process, but is carried out on a lamina distribution system, the stationary phase being spread over, and adhering to a lamina surface called the TLC ‘plate’. The mobile phase flows over the surface, usually driven by surface tension forces, and the solutes are eluted across the surface and are separated. After development, the plate is dried and the surface subjected to one of a number of different techniques that render the solutes visible as ‘spots’ on the plate. Thus the separation appears as a number of (more or less) circular colored spots on the plate spreading from the point of injection to the position of the solvent front. The relative position of the spot is a characteristic of the specific substance and the diameter and intensity of the spot is related to the amount of material present in the spot.