**7.1 Thin layer chromatography (TLC)**

 Stahl gave the first practical application of thin layer chromatography. TLC is a most versatile technique and it shows its separation with good speed. Advantage of TLC is its sensitivity. TLC works on the principle of an adsorption chromatography in which samples were separated. Separation is based on the interaction between a thin layer of adsorbent attached on the plate and solvent system. The technique is mostly used for the separation of low molecular weight compounds. Many different adsorbents are used in TLC like silica gel, aluminum, cellulose powder, starch, etc. and can be used to separate various compounds like amino acids, alkaloids, phenols, steroids, vitamins, etc.

It is being implemented extensively due to the following reasons:

