Extraction of Caffeine Many undergraduate organic chemistry laboratory manuals describe procedures for extracting caffeinefrom coffee or tea. While the experiment interests most students and sdequately teaches the principles of extraction i t tends to bog down during the filtering process, especially in laboratories which use micro apparatus. To produce enough caffeine far beginning students to manipulate well requires large qusntities of tea and coffee whichare difficultly filtered. Also the average student almost always encounters tight emulsionswhich me difficult to break up. We have discovered that far better results can he obtained by extracting caffeine from No-Doe Tablets. The problems stated above are avoided without ssorificing the principles and technique of extraction or the "fun" involved in working with a known substance. Unlike experiments using coffee or tea, this experiment can be completed by most students in 2 hr.
Experimental Procedure Into a beaker, place three weighed No-Doa tshlets, a. boiling chip, and 150 ml of water. Boil the mixture for !O min to ensure solutlon of the caffeine, then filter the hot solution through a Biichner funnel containing a. very thlu Celitemter pad. The binder in No-Doa tablets will remain in suspension. Cool the mixture, and add i t along with 25 ml of chloroform to s separatory funnel. Gently swid thelayers together for five minutes. Allow the layers t o separate and remove the chloroform (bottom) layer. (Mix the solutions thoroughly during each extraction, but do not shake the phases vigorously, for a very tight emulsion may form.) Cmry out theextraotion process three times. Pour the combined chloroform extracts into s n Erlenmever flask and add 0.5 a of sodium sulfate. Decant the rhloroforln holmion f r m the soditin? sulfate intu a fla.k. .Mi a trokerr w orl .iplin; or a huilirng chip to the s,lutiun to ~ , r c v e nvident ~ h u p i n y nud evap
