Extraction of Caffeine from Tea
-- Experimental Organic Chemistry, Charles F. Wilcox Jr., Mary F. Wilcox.
DISCLAIMER: SOME OF THE MATERIALS USED IN THIS EXPERIMENT ARE POISIONOUS TO INGEST!.
I will provide MSDS links to all materials used
30g tea leaves
(about 25 tea bags)
300 mL Water
15g Calcium Carbonate
100 mL Dichloromethane
- http://www.jtbaker.com/cgi-bin/msds-s.pl?searchdata=9324) TOXIC
s - (http://www.jtbaker.com/cgi-bin/msds-s.pl?searchdata=9309) TOXIC
CO) - http://www.jtbaker.com/cgi-bin/msds-s.pl?searchdata=9006) TOXIC
500 mL Erlenmeyer Flask
(plus vacuum source)
Separatory funnel for Extractions
Boil the mixture gently, occasionally swirling it.
After 20 minutes, add 5 g Celite.
Filter the hot mixture on a Büchner Funnel, and press the filter cake firmly with a large cork to obtain as much of the liquid as possible.
Cool the liquid obtained to 15-20°C, and transfer it to a separatory funnel.
Extract the caffeine with four successive 25-mL portions of dichloromethane. (Jeremy's note: look in an Organic Chemistry lab book for directions on how to do Extractions. Extractions are quite simple once learned, but it can still be a pain to know what material you want when you're doing the extractions -- in this case, you keep the stuff you extract, and throw away what's left in the Extraction Assembly)
Transfer the extracts to a simple-distillation assembly, and distill off all but 10 mL of the solvent on a steam bath. Save the recovered solvent.
Pour the warm concentrated solution of caffeine into a small beaker and rinse the flask with 5 mL of the recovered solvent.
Evaporate the combined solutions to obtain a crude product (use a hot plate).
To purify, dissolve in about 5 mL of Acetone by warming the mixture on a steam bath; add dropwise just enough mixed hexanes to turn the warmed solution faintly cloudy; then allow the solution to cool and allow the product to crystallize.
Collect the green-tinged crystals on a small vacuum filter and wash them with a little mixed hexanes. The crystals may have a greenish tint, and can be removed by sublimation.
- In a 500-mL Erlenmeyer Flask, combine
Expected yield: 0.048g (48mg) Caffeine (C8H10N402)
Melting Point of Caffeine (to test for purity): 236°C
IF YOU PLAN TO INGEST ANY OF THIS CAFFEINE, TAKE IT TO A CHEMISTRY LAB TO HAVE IT TESTED FOR PURITY!(even then, it's still not a good idea to try any of this stuff ;)