Extraction of Caffeine from Tea Leaves

Solubility, Caffeine, Liquid–liquid extraction

Abstract: Caffeine, (C8 H10 N4 O2) a white, crystalline alkaloid known as a nervous system stimulant found commonly in tea leaves and coffee, can be extracted using the method of sublimation with the use of Methylene Chloride (CH2Cl2) and Sodium Hydroxide; both can repeatedly rinse the green (unroasted) coffee beans from the caffeine. Keywords: Caffeine, Methylene Chloride, Sodium Hydroxide, Anhydrous Sodium Sulfate I.Introduction

Caffeine is an alkaloid of the methylxanthine family. Its chemical formula is C8H10N4O2 and its systematic name is 1,3,7-trimethylxanthine or 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6-dione (See Fig. 1). In terms of physical properties, pure caffeine occurs as odorless, white, fleecy masses, glistening needles or powder. Practically, caffeine is a central nervous system (CNS) stimulant, having the effect of temporarily warding off drowsiness and restoring alertness. Beverages containing caffeine, such as coffee, chocolate, soft drinks, and energy drinks, enjoy great popularity. Caffeine is the world's most widely consumed psychoactive substance, but, unlike many other psychoactive substances, it is legal and unregulated in nearly all jurisdictions. [1] Tea is another common source of caffeine. Although tea contains more caffeine than coffee (by dry weight), a typical serving contains much less, as tea is normally brewed much weaker. Besides strength of the brew, growing conditions, processing techniques- and other variables also affect caffeine content. Certain types of tea may contain somewhat more caffeine than other teas.


Firstly, the extraction must be considered. Three tea bags were opened and the combined weights of the tea leaves were taken. Recording the weight is necessary. The tea leaves were returned in the bags. The next step was boiling of the tea bags in 100 mL distilled water for 10 minutes in a beaker (See Fig. 2). Boiling it for more than ten minutes would be better. After that, the side of the...
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