❤️Food Science Universe (FSU)
Caffeine is the most widely consumed psychoactive drug and as you likely know it’s found in many food products in this video we’ll be extracting caffeine from green tea but almost any other type of tea could be used for this extraction i used 45 milliliters of dichloromethane water 60 bags and 6 grams of sodium carbonate 60 bags were added to a beaker then 90
Millilitres of water was added this was followed by 6 grams of sodium carbonate once the sodium carbonate is mixed thoroughly the solution is brought to a boil by boiling the tea we are separating out the water soluble components which is mostly caffeine and tannins the tannins are acidic and react with the sodium carbonate in solution to form salts we are going
To separate the caffeine from the water layer using an organic solvent and salting the tannins should keep them in the aqueous layer boil the solution for about 10 minutes it is recommended to place something on top of the beaker to limit water loss if the heat is high it might bubble a lot and to prevent it from overflowing remove the lid and let the bubbles
Settle after 10 minutes the concentrated tea extract was transferred to an erlenmeyer flask the teabags were pressed in order to release as much water as possible which was then also decanted into the erlenmeyer flask now 60 milliliters of water is added and the process was repeated the tea extract was combined with the previous tea extract and again the teabags
Were squished to release as much water as possible the solution was then allowed to stand and cool down to room temperature this step is optional and probably not required but i decided to filter the tea extract prior to the separation process if you choose not to do this you can transfer it directly to a separatory funnel i washed the filter with 15 milliliters
Of dcm but if you didn’t filter it you can add the dcm directly to the separatory funnel so after adding the dcm you should have 2 layers the central front was capped and shaken very gently in to prevent the formation of an emulsion afterwards the layers were allowed to settle and the bottom dcm layer was drained this extraction process was carried out a total
Of three times using 15 milliliters of dcm each time the organic layer was dried using calcium chloride and then filtered into a round bottom flask the filter is washed with a small amount of dcm i set up a distillation to remove and recover the dichloromethane at the bottom of the round bottom flask we are left with some dry crude caffeine this was removed and
Transferred to a test tube a small amount of dcm was used to wash the round bottom flask which was transferred to the test tube using a hot plate the small amount of dcm was evaporated off the crude caffeine was then recursively is using 95% ethanol the crystals were vacuumed filtered and the test tube was washed using ice-cold 95 percent ethanol the crystals were
Dried under vacuum and we were left with nice white nearly pure caffeine crystals unfortunately yield was quite low and it was only around 30 milligrams an nmr of the product shows that the caffeine is quite pure you
Transcribed from video
How to extract Caffeine from Tea (Classic DCM Method) By WBS-World Best Services