Thin layer chromatography (TLC) (Principle, procedure steps, visualisation and applications)

This video describes the thin layer chromatography (TLC) technique. It explains the separation process, where the different components present in the mixture. The principle of this method is explained. How various components present in the mixture based on the difference in the affinity between the stationary phase and the mobile phase. Calculation of the retention factor(Rf). List out the advantages and disadvantages is discussed. Various applications of this method is explained. The mechanism of this method is explained. the different methods of visualising techniques is explained. Iodine method, ninhydrin, UV light etc. The calculation of Rf factor i.e retention factor is explained. How different components are separated based on the difference in the polarity is explained.
Thin layer chromatography (TLC)
You will be able to
elucidate the principle of thin layer chromatography.
explain the procedure to separate and identify the components of a mixture by thin layer chromatography.
discuss the various methods of visualizing the separated components.
list out the advantages, disadvantages and applications of this technique.
Principle of Thin layer chromatography
Thin layer chromatography (TLC) is a technique used to identify the components/compounds present in a mixture by separating them using a thin stationary phase (silica gel) supported on an inert substrate and a mobile phase (solvent).
Stationary phase – silica gel, alumina etc. over glass/metal plate, plastic sheet etc.
Silica gel – acidic – steroids, amino acids, hydrocarbons etc.
Alumina – basic – amines, bile, lipids etc.
Cellulose – neutral – carbohydrates, sugars etc.
Mobile phase – developing solvent/mixture of solvents (reasonably volatile)
Sample – sample containing mixture of compounds and/or individual compounds
Silica gel – acidic – separation follows adsorption mechanism.
Spotting – spot the samples/references using a capillary tube/micropipette on the line drawn 1cm above the bottom
Developing - developing solvent should be below the level of spotted samples.
mixtures of strongly polar compounds
polar compounds -10% methanol in DCM
strongly basic components -10% NH4OH in methanol in dichlormethane
Visualisation :
coloured samples – Just dry to vapourise the solvent
uncoloured samples
Iodine chamber – place iodine crystals in the chamber
Fluorescent substance added to stationary phase (silica gel), which will fluoresce/glow in UV light leaving the dark spots.
Advantages of Thin layer chromatography
Disadvantages of Thin layer chromatography
Applications of Thin layer chromatography

Видео Thin layer chromatography (TLC) (Principle, procedure steps, visualisation and applications) канала Revathi Purushothaman