When the solvent has reached the top of the plate, the plate is removed from the developing chamber, dried, and the separated components of the mixture are visualized. In principle, the components will differ in solubility and in the strength of their adsorption to the adsorbent and some components will be carried farther up the plate than others. This liquid, or the eluent, is the mobile phase, and it slowly rises up the TLC plate by capillary action.Īs the solvent moves past the spot that was applied, an equilibrium is established for each component of the mixture between the molecules of that component which are adsorbed on the solid and the molecules which are in solution.

The TLC plate is then placed in a shallow pool of a solvent in a developing chamber so that only the very bottom of the plate is in the liquid.

A small amount of the mixture to be analyzed is spotted near the bottom of this plate. TLC is also used to support the identity of a compound in a mixture when the R f of a compound is compared with the R f of a known compound (preferably both run on the same TLC plate).Ī TLC plate is a sheet of glass, metal, or plastic which is coated with a thin layer of a solid adsorbent (usually silica or alumina).

TLC is a simple, quick, and inexpensive procedure that gives the chemist a quick answer as to how many components are in a mixture.

Origin thin setup