Extracting pure caffeine from tea (idea)

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

Materials

30g tea leaves (about 25 tea bags)
300 mL Water
15g Calcium Carbonate (CaC0₃ - http://www.jtbaker.com/cgi-bin/msds-s.pl?searchdata=1288)
100 mL Dichloromethane (CH₂Cl₂ - http://www.jtbaker.com/cgi-bin/msds-s.pl?searchdata=9324) TOXIC
5-10g Celite (http://www.jtbaker.com/cgi-bin/msds-s.pl?searchdata=3371) TOXIC
Mixed Hexanes - (http://www.jtbaker.com/cgi-bin/msds-s.pl?searchdata=9309) TOXIC
Acetone - ((CH₃)₂CO) - http://www.jtbaker.com/cgi-bin/msds-s.pl?searchdata=9006) TOXIC

Equipment needed

500 mL Erlenmeyer Flask
Büchner Funnel (plus vacuum source)
Separatory funnel for Extractions
Small Beaker
Distillation Assembly
Filter Paper

Procedure

• In a 500-mL Erlenmeyer Flask, combine
  • 30 g ordinary dry tea
  • 300 mL water
  • 15 g powdered Calcium Carbonate.
• 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.

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 ;)