Essay Example on Thin layer chromatography TLC is a quick and Inexpensive

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Thin layer chromatography TLC is a quick and inexpensive analytical technique that indicates how many components are in a mixture The chromatography works according to the principle that different compounds have different solubility and adsorption Thin Layer Chromatography TLC is a solid liquid technique in which the two phases are a solid stationary phase and a liquid mobile phase In the TLC technique usually using a plastic sheet or glass which is coated with tin layer of a solid absorbent substance usually it is silica TLC plate is a stationary phase The paper is dipped into solvent which is a mobile phase The solvent dissolves the samples and carries them up the paper The substance unknown can be identified by comparing the horizontal spots Ninhydrin is using for detection of amino acids amines amino sugars Since amino acids are colourless compounds ninhydrin is used for detecting them To identify this after development the TLC plate is sprayed with ninhydrin reagent and dried in an oven Ninhydrin reacts with α amino acids that results in purple coloured spots


TLC is a quick microscale technique that can be used to determine the number of components in a mixture verify a substance's identity monitor the progress of a reaction determine appropriate conditions for column chromatography analyze the fractions obtained from column chromatography In practice veterinary chemistry and toxicology studies using thin layer chromatography used to identify many pesticides alkaloids mycotoxins organic compounds heavy metals The method is simple using the technique does not require complex equipment has a high enough sensitivity and specificity In forensic science TLC is used for the identification and comparison of drugs explosives inks and dyes Method On the TLC plates used pencil draw a line across the plate about 1 5 cm from the bottom It be a baseline On the base line mark a spots there be dropped the samples Standard lysine marked letter L Standard glutamate marked letter G Standard phenylamine mark letter P Unknown amino acid mixture marked letter U Dropped the amino acids on the plates and leave to dry Then TLC plate is added to the fume cupboard and left for 40 minutes After 40 minutes the plate is removed from the fume cupboard Need kept laboratory rules because working with dangerous liquids TLC plate hold on the corner and dry with hairdryer 


When the results are seen on the plate Results Result of this experiment is to find an unknown amino acid and distance moved by solvent Measure from the starting point to the centre of the spot on the TLC plate when the distance from the starting point to the solvent front After a separation is complete individual compounds appear as spots separated vertically Each spot has a retention factor Rf which is equal to the distance migrated over the total distance covered by the solvent The Rf formula is Rf distance spot travel distance solvent travel In the table 1 you can see the result of the experiment The result of an experiment with Standard Glutamates failed Attached a photo in to fragile 1 showing how the result was received As well as illustrating the next result of the photo in to fragile 2 we can compare what should be the result Table 1 Results of experiment Sample Distance moved cm Solvent front Rf Standard lysine 6 3 cm 8 3 cm 1 32 Standard glutamate No result 8 3 cm No result Standard phenylamine 6 7 cm 8 3 cm 1 24 Unknown amino acid mixture 6 3 cm 8 3 cm 1 32 Fragile 1 Fragile 2 Discussion The experimental results show how amino acids react with the regents Spots are not visible until is done by spraying with a solution which reacts with solutes to make them visible The horizontal spots which are on the TLC plate is experiment results As well as during the experiment was made unsuccessful mistake with glutamate or the result was not seen to some reason In the experiment a plate is dipped into solvent The solvent dissolves the samples and carries them up the paper The substance unknown can be identified by comparing the horizontal spots So we discovered that the unknown sample was a lysine The reasons why they may not be spots on the plates The development method needs to be changed Due to the failure of the experiment there is no sample in the compound The solvent system level is too high If the level of the solvent system in the chamber is greater than the place where the plate is inserted the compound from the point is soluble in a solvent rather than migrating the plate Sample concentration amount is too low You can overcome this problem by seeing the sample several times on the slide allowing the solvent to dry between applications The sample has to be fresh


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