Extraction of Caffeine from Tea Bags
Extraction of caffeine from tea bags
ABSTRACT
Caffeine extraction from the commercial tea leaves (Lipton Yellow Label Tea) that was done is multiple extraction. 4 tea bags were used in the experiment; tea leaves were weighed having 8.5333 grams. The leaves were boiled in a beaker with 150ml of water; the aqueous tea extract was transferred in a seperatory funnel mixed with DCM (20ml), done thrice. The DCM layer was washed with 20ml 6M NaOH in the seperatory funnel; the organic layer was dried with anhydrous Na2SO4. The dried organic layer turned into crude caffeine was purified in a sublimation set-up. A capillary tube was used to insert the pure caffeine to determine its melting point, having 228°C - 229°C. The purified caffeine from the sublimation set-up was weighed having 0.0007g; using the wt. of the sample and the wt. of the pure caffeine, the %yield was determined, 8.20 x 10 -3 %.
It was noticed during the steps of the experiment involving the electronic scale that the number displayed never seemed to reach equilibrium. Even when the furniture containing the scale was closed and no one was moving nearby, the number on the display continued to fluctuate within a range of approximately 0.01 g. Thus, even though the Caffeine was massed at 0.109 g, it could actually have been anywhere between 0.099 g and 0.119 g.
It is also possible that some Caffeine was lost during the use of the separatory funnel. To insure a pure result, the separatory funnel was not emptied completely of the organic layer. Almost 1 cm of organic layer was left in the funnel after each release. Every time the solution was transferred from one beaker to another, some Caffeine could have been left behind coating the container. Finally, some Caffeine might have been lost or destroyed during the evaporation process.
This experiment has been described by one source as "a popular second-year organic experiment." Since the experimenter is currently working with a high school level of
ABSTRACT
Caffeine extraction from the commercial tea leaves (Lipton Yellow Label Tea) that was done is multiple extraction. 4 tea bags were used in the experiment; tea leaves were weighed having 8.5333 grams. The leaves were boiled in a beaker with 150ml of water; the aqueous tea extract was transferred in a seperatory funnel mixed with DCM (20ml), done thrice. The DCM layer was washed with 20ml 6M NaOH in the seperatory funnel; the organic layer was dried with anhydrous Na2SO4. The dried organic layer turned into crude caffeine was purified in a sublimation set-up. A capillary tube was used to insert the pure caffeine to determine its melting point, having 228°C - 229°C. The purified caffeine from the sublimation set-up was weighed having 0.0007g; using the wt. of the sample and the wt. of the pure caffeine, the %yield was determined, 8.20 x 10 -3 %.
It was noticed during the steps of the experiment involving the electronic scale that the number displayed never seemed to reach equilibrium. Even when the furniture containing the scale was closed and no one was moving nearby, the number on the display continued to fluctuate within a range of approximately 0.01 g. Thus, even though the Caffeine was massed at 0.109 g, it could actually have been anywhere between 0.099 g and 0.119 g.
It is also possible that some Caffeine was lost during the use of the separatory funnel. To insure a pure result, the separatory funnel was not emptied completely of the organic layer. Almost 1 cm of organic layer was left in the funnel after each release. Every time the solution was transferred from one beaker to another, some Caffeine could have been left behind coating the container. Finally, some Caffeine might have been lost or destroyed during the evaporation process.
This experiment has been described by one source as "a popular second-year organic experiment." Since the experimenter is currently working with a high school level of
References: http://www.oxford.net/~mavarod/portal/school/caffeine.html http://www.google.com.ph/#sclient=psy-ab&hl=tl&site=&source=hp&q=extraction+of+caffeine