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However, a serving of coffee contains roughly twice the caffeine of tea. Much of the flavor of coffee and tea comes from tannins and other flavoring agents. Caffeine has a slightly bitter flavor. ... Rinse the residue in the flask with two successive 1-mL portions of acetone to extract the crude caffeine.
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fido.pcc.edu/reserves.archived/Moffett,Gabriella/Fall02...
fido.pcc.edu/reserves.archived/Moffett,Gabriella/Fall02/CH241LABS/ExtractionofCaffeinefromTeaLeaves.pdf
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crude caffeine contains approximately 85% caffeine and remaining water soluble components gives greenish appearance. ... more
http://www.experts123.com/questions/filter/caffeine
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Evaporate it down (carefully and slowly --EtOH is fairly flammable too) and you have crude caffeine extract. Don't use this stuff! Dissolve it up in a minimum of boiling vodka, (40-50% EtOH in water) reduce it to ~80% volume, and then let it cool.
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www.hoboes.com/pub/Prohibition/Legal%20Drugs/Caffeine/C...
www.hoboes.com/pub/Prohibition/Legal%20Drugs/Caffeine/Caffeine%20FUQ
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The residue will be crude caffeine (usually slight green in color) (determine its weight-the yield will be 0.5 g approx for 25 g of tea leaves). Purify the crude caffeine either by sublimation or by recrystallization using methanol.
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www.pharmainfo.net/reviews/extraction-caffeine-tea-leav...
www.pharmainfo.net/reviews/extraction-caffeine-tea-leaves
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You can find the structure of caffeine on p. 27 of the McMurry textbook. The structure of cellulose is on p. 970 of the McMurry textbook. ... When the solvent has evaporated, the solid caffeine will coat the bottom of the flask. Weigh the flask to get the mass of your crude caffeine. ... Why is the crude caffeine slightly green?
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web.centre.edu/muzyka/organic/lab/caffeine.htm
web.centre.edu/muzyka/organic/lab/caffeine.htm
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Oct. 20, 22 Caffeine ... Organic acids and bases can be separated from each other and from neutral compounds by extraction using aqueous solutions of different pH. Most organic acids (e.g., carboxylic acids) are insoluble or slightly soluble in water, but these compounds are highly soluble in dilute aqueous sodium...
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web.centre.edu/che/nmr_workshop/24_lab_manual.htm
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Compare with Amazing Grass, which is cheaper, but has fewer ingredients, Greens First, which is a slightly more robust formula for a slightly higher price, Greens Pak, also a slightly more robust formula, and ultimately Green Vibrance, ... I might suggest some green tea powder (for those who don’t mind a little caffeine),
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www.greendrinkreviews.com/wp/category/greendrinks/
www.greendrinkreviews.com/wp/category/greendrinks/
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For years, you’ve bagged up old T-shirts, slightly chipped dinnerware, and more bridesmaids dresses than you care to admit, then hauled them to Goodwill, where castoff possessions become someone else’s great find. ... As if these two great benefits from reusable mugs aren’t enough, you can even save a little green.
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greenpieceindy.com/blog/
greenpieceindy.com/blog/
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The solid residue in the round bottom flask is your crude caffeine. Allow the flask to cool to room temperature. (If the product is green, add some hexane and shake well. The caffeine is insoluble but the impurities dissolve in the hexane and can be removed with a clean dry pipette.);
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firstyear.chem.usyd.edu.au/LabManual/E25.pdf
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