Wednesday, February 27, 2013

Extraction of Caffeine from Tea

Experiment 1: Extraction of Caffeine from Tea
The primary intent of the experiment is to separate the caffeine from tea leaf leaves. The mixture of tea and the calcium carbonate is separated from tea leaves by clean filtration. The sol handout used in extraction of caffeine is methylene chloride. anhydrous magnesium sulfate is added to the methylene chloride solution to dehydrate the mixture. The dichloromethane is then separated from the mixture in the rotary evaporator.

realise 1: The structure of caffeine is very similar to those of purine bases (adenine and guanine) in DNA, therefore caffeine is a good substance to pattern on for dealing with nucleic acids.

Procedure
Approximately 10g of tealeaves, CaCO3 (4.8g, 0.048 mol) and deionised H2O (100mL) is added into a beaker and stewed for 15 minutes. The mixture is then cooled to 20?C and is tensed utilise a Buchner funnel (vacuum filtration). The extraction process is when a solvent, dichloromethane (15mL) is added to the filtrate in a separatory funnel; the mixture is thinly swirled together 3 times, and stopcock is released in between to vent the funnel. Dichloromethane (including the emulsion) is then drained from the bottom into a 50mL Erlenmeyer flask.

Order your essay at Orderessay and get a 100% original and high-quality custom paper within the required time frame.

aforesaid(prenominal) extraction process is repeated on the same filtrate and the dichloromethane is, once again, let out to the same 50mL Erlenmeyer flask as before. The combined dichloromethane solution and water (20mL) is poured into a rinsed separatory funnel. Mixture is gently swirled and drained out into an Erlenmeyer flask. Anhydrous magnesium sulfate is added to dehydrate the washed mixture.
The solution is then filter into a weighed, dry, 100mL Erlenmeyer flask. Dichloromethane in the mixture is vaporized with a rotary evaporator. The Caffeine, white powder residue, (0.0486g) should be obtained.

Results
Caffeine: C8H10N4O2
commentary: a white tasteless substance
The amount of caffeine obtained from 10g of tealeaves: 0.0486g/ 48.6mg

Discussion...If you motivation to get a full essay, order it on our website: Orderessay



If you want to get a full essay, wisit our page: write my essay .

No comments:

Post a Comment