Organic Chemistry Caffeine Extraction Lab ( Tea Bags ) essays

Organic Chemistry Caffeine Extraction Lab ( Tea Bags ) essays To demonstrate the isolation of a natural product from a biological source (tea bags) using extraction techniques, and to demonstrate purification by sublimation. In a 400ml beaker, 15 tea bags were submerged in approximately 125ml of water. This was brought to a boil over a bunsen burner and allowed to boil for about 15 minutes. The tea bags were removed from the tea infused water and discarded. 15 grams of Na2CO3 was dissolved in the tea water by stirring, and allowed to cool. It was then transferred into a reparatory funnel. 20ml of Methylene chloride was added and this mixture was shaken gently. The two distinct layers were separated using the water drop technique and the aqueous layer was mixed and extracted with another 20ml of Methylene chloride. The organic extracts were combined in a conical flask and dried with about 1gram of anhydrous MgSO4. The solution was allowed to stand for about 10 minutes, and swirled occasionally to complete the drying. The Methylene chloride solution was gravity filtered into a small, pre-weighed beaker. The solvent was carefully evaporated to dryness and the beaker containing the crude caffeine was re-weighed to calculate the yield. Many useful organic compounds are present in, and can be extracted from, naturally occurring sources. One of the most widely used drugs in the United States is caffeine, an alkaloid, which is present in coffee, tea, soda, chocolate, and many non-prescription drugs. An alkaloid is defined as a basic nitrogen containing organic compound. Caffeine is soluble in water because it has several polar and basic functional groups. This property also makes it insoluble in aqueous base. By adding a weak base to an aqueous solution of tea extract, one can decrease its solubility in water and increase its solubility in a less polar organic solvent, into which the caffeine can be easily extracted, using a separatory funnel. After evaporation of the organi ...