**7. Chromatography techniques**

Chromatography is a technique where the molecules are separated based on their shape, size, and charge. In any extract, there are hundreds of unknown components and many of them are in very low amount. During chromatography, analyte in

#### *Pharmacognosy - Medicinal Plants*

 solvent and move through solid phase that acts as a sieving material. As molecule proceeds further through molecular sieve, it gets separated. Moreover, there usually exists variability within the same herbal materials. Hence, it is very important to obtain reliable chromatographic fingerprints that represent pharmacologically active and chemically characteristic components of the herbal medicine. Thin layer chromatography is a chromatographic technique that readily provides qualitative information and through which it becomes possible to obtain quantitative data [17].
