M. S. Ntamila and A. Hassanali University of Dares Salaam P.O. BOX 35061 Tanzania
kolation of Oil of Clove and Separation of Eugenol and Acetyl Eugenol . An instructive experiment for beginning chemistry undergraduates chloride, and hydroxamic ester tests, and the preparation of the henzovl derivative of eupenol. Finally, ir spectra of the two components are examined, and the information ohtained comoared with that from chemical tests. Practical Detalls Crush about 30-35 g of cloves with pestle and mortar and place in the distillation flask (500 ml) containing about 100 ml water; steam-distil for 1% hr heating both the boiler and the distillation flask. The receiver contains oil of clove, some separated and some dispersed in water. Extract the mixture with 3 portions of 25 ml chloroform. Examine the chloroform extract using the tlc plates (Silica Gel coated plates and running with chloroformlligroin: Y4). Develop the plate by exposing to iodine vapor or preferably spraying with concentrated sulfuric acid in ethanol and then heating a t 120°C. Retain a small sample (0.5 ml) of the chloroform solution. For the separation of the two major components, extract the chloroform solution with 3 portions of 25 ml 5% sodium hydroxide solution. The chloroform layer which now contains mainly acetyl eugenol is dried over anhydrous sodium sulfate, filtered, and the chloroform removed by distillation. Yield of acetyl eugenol: 0.2-0.3 The combined alkali extracts are made acid to litmus by the addition of hydrochloric acid and extracted with chloroform. The chloroform extract is similarly dried over anhydrous sodium sulfate, filtered, and evaporated to dryness. Yield of eugenol: 2-3 g. Examine solutions of eugenol and scetyl eugenol against that of the original extract by thin-layer chromatography. The original oil of clove will be seen to have been clearly separated into its two major components. ' T h e isolation of caffeine from tea is one of the oldest experiments...
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