Thin Layer Chromatography

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Abstract This report describes the methods of chromatography. Thin-layer chromatography was used to identify compounds in a mixture by separating them and purifying substances. It was found that the unknown BC headache power contained caffeine, salicylamide, and acetyl-salicylic acid. Paper chromatography was used for separating small amount of materials (in this case food dyes) into their components. It was found that the dyes moved different distances and that some of the dyes were made of different dyes mixed together. Gas-liquid chromatography was used for separating and analyzing the components fractional distilled from a hexane-toluene mixture. Introduction Thin-layer chromatography is used to identify compounds in a mixture by separating them, and to purify substances. The components of a mixture are separated though the use of capillary action. In this case a TLC plate is used that is coated with silica gel (4). The molecules bind to the porous surface of the TLC plate based on different types of intermolecular interactions. The filter paper keeps the air in the beaker saturated with solvent so that the solvent does not evaporate from the TLC plate. The watch glass closes the system so that evaporation does not occur (1). Under the UV light, the distance the compounds traveled were easily spotted because the TLC plates were fluorescent everywhere except the spots of the compounds. Thin-layer chromatography was used for this experiment because the commercial pain killers contain a mixture of compounds and TLC allows one to visualize the number of ingredients in a mixture (4).Reference picture one. Paper chromatography is a form of partition chromatography that is used for separating small amount of materials into their components. The cellulose of the filter paper contains absorbed water so the partial coefficients between the absorbed water and the
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