Case Study On Chromatography

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CHROMATOGRAPHIC STUDY Among the various methods of separating plant constituents, the chromatographic procedure originated by Tswett is one of the most commonly used techniques of general application. Chromatography represents a group of methods for separating molecular mixtures that depend on the differential affinities of the solute between two immiscible phases. One of the phase is a fixed bed of large surface area which is called a stationary phase, while the other is a fluid or gas which moves through or over the surface, which is called the mobile phase. The stationary phase may be a porous or finely divided solid or liquid that has been coated as thin layer on an inert support material. The mobile phase may be a pure liquid or a mixture…show more content…
It is at present an important analytical tool for qualitative and quantitative analysis of a number of natural product. The adsorbent such as silica gel G or C is coated to a thickness of 0.3 mm on clean TLC plates using commercial spreader , the plates are activated at 1050C for 30 minutes and used. The selection of mobile phase depends upon type of constituents to be analysed after the development of chromatogram by ascending techniques, the resolved spots are revealed by spraying with suitable detecting agent.TLC has certain advantages over paper chromatography fraction can be effected more rapidly with smaller quantities of mixture, spots are usually more compact and drastic reagent , such as concentrated sulphuric acid can be used as spraying solution .The TLC technique is useful in analysis of alkaloids, glycosides, isoprenoids, lipid components,sugars and derivatives and practically all bioconstituents. The Rf values (distance travelled by component /solvent front) may vary depending upon purity of solvent, nature of substance to be resolved , composition of solvent , presence of impurities, adsorbent used, polarity of the solvent substances and adsorbent…show more content…
The coated plate was allowed to activate at 1000 for 10 min.The crude extract (250 mg) dissolved in ethanol (20 m),was spotted on silica plates and dried.In a beaker the mobile phase was prepared and allows the mobile phase chamber to activate.After activation of chamber the spotted plates were allowed to separate the plant constituents completely. After complete separation of compounds, the plates were dried and analyzed under visible light and the Rf value of each separated constituents was calculated by the formula. The Rf values was calculated as follow: Distance traveled by component Distance traveled by mobile phase 4.5.2. TLC of ethanol extract of M. annua TLC analysis of Martynia annua (L.) seeds extracts was carried out to determine the chemical constituents found in the seeds of Martynia annua L.- Toluene: ethyl acetate : mehtanol (10:10:2) v/v ) was used as the mobile phase and silica gel –G coated glass plates as stationary phase. Table 4.4: Different solvent system for TLC of Ethanolic extract of Martynia annua seeds . Sr. No. Solvent system Detection Spot observed 1 Chloroform: Benzene (10:8) Iodine Chamber 2 Iodine

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