Caffeine Extraction Lab Report

Acid-Base Extraction and The Extraction of Caffeine from Tea Bags and Purification by Sublimation.

Summary:

The isolation of organic compounds in a solution can be performed due to the difference in solubility in different liquids. The extraction of the benzoic acid ,3-nitroaniline and 9-flourene mixtures by adding different amounts of solvents and extracting the acidic, basic and the organic solvents the purity of the samples were then determined by comparing them to the literature value of the melting point. The percent recovery for the benzoic acid was 81.1%, the 3-nitroaniline was 52.9% and the organic extract was 158.8% this was cause by a large number of impurities that had occurred whilst conducting the experiment. The benzoic acid was found in the acidic extract while the 3-nitroaniline was found in the basic extract and the organic extracted contained the 9-flourene, this was determined by the comparison of the melting point range to the actual value. After the extraction of caffeine from the tea bags

Once cool to touch the squeeze out all the tea bags carefully without tearing them apart. Using a separatory funnel extract three times with 15.0ml of dichloromethane gently rocking bath and forth the funnel venting the funnel often each time. Carefully decant into a pre-weighed 125ml flask and add the drying agent-calcium chloride pellets- and the organic layer was evaporated off in a warm water bath. Using aluminum foil as support around the mouth of the flask place test tube in the flask and heat the flask on a hot plate whilst adding water into the tube without letting it boil. Once the caffeine forms crystals around the test tube scrape off all the sublimed product and weigh the dried product 0.1grams of caffeine and had a melting point range of 175-230