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Lab 1 extraction of Organic compound.docx

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Lab1Extraction and Purification of Natural Products CHM2123 TADue date September 23 20131 Theory and MechanismsThe objective of this lab is to review the major techniques that are done in isolating and purifying products once a chemical reaction is done These major techniques include Extraction Recrystallization and Thin Layer Chromatography and each of them has specific methods and purpose in investigating and analyzing any desired products Moreover these desired products are analyzed in 2 parts of the Lab each gotten through either of the three separation techniques In part A the desired product is caffeine which an organic compound found in Green and Black Tea where concentration of it in green tea is less than Black tea and it is a form of Alkoilds For the propose of this lab Black Tea would have to undergo boiling to extract various compounds that are composed of the tea which are polyphenol caffeine and Theranie then extraction which is a technique used to separate mixtures through the principle ofpolarity and affinitysoluble among soluble compounds Moreover the main reaction occurs when NaCOdissociate 23 and acts as a nucleophile deprotonating the OH groups on any of the 2 forms of the Polyphenol therefore increases itpolyphenols polarity and solubility in the aqueous phase Drying with the help of a drying Agent like Ionic crystal compounds recrystallization which involves dissolving the impure compound in hot solvent filtering out insoluble impurities and Suction filtration to gain desired product Caffeine in this part of the labMechanism 12NaCO2Na CO23saq3aq On the other hand part two which is the extraction of carotenoids and chlorophylls from spinach leaves doesnt require any form of those separation techniques listed above except the Liquidliquid extraction The purpose of the step is to separate and identify different pigments found in the sample alongside compare the solubility with respect to their relative chemical structures and functional groupsMeanwhile the separation technique that is common among the two parts of the lab is called Thin Layer Chromatography which serves different purpose to the steps In step1 TLC would be used to compare the relative purity of the Crystals caffeine with the crude one and the authentic one While the purpose of TLC in part 2 is to separate and analyze the difference in polarity between the carotenoids and the Chlorophylls through changes in the polarity of the mobile phaseFinally the melting point of the crystal caffeine is determined by using the Gallenkamp melting apparatus instrument This is done by placing the sample tube containing the crystal in the hold onto of the instrument and then the melting point range is given when the temperature starts and stops2Table of ReagentsPart 1 Extraction and Purification of Caffeine from Black Tea
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