Pharmaceutical Analysis

Thin layer chromatography is a technique used to separate non-volatile mixtures.It is performed on a sheet of glass, plastic, or aluminium foil, which is coated with a thin layer of adsorbent material, usually silica gel, aluminium oxide (alumina), or cellulose.

Transmittance is the amount of light transmitted by a sample and is mathematically related to absorbance.  

It is the ratio of intensity of transmitted radiation to intensity of incident radiation.

a channel used to convey a liquid in descending paper chromatography.

In this a square or rectangular paper is used.the sample is applied to one of the corners.the second development is performed at right angle to the direction of the first run..This type of chromatography can be carried out with identical solvent systems in both the directions or by two solvent systems.