Caffeine Extraction from Tea Leaves
Extraction of Caffeine from Tea Leaves
Marc Tugaoen, Kristine Vanzuela, Rafael Villanueva, Justeen Wong
Department of Chemistry, University of Santo Tomas, Manila, Philippines
Abstract
This experiment has been divided into 4 set-ups, first was the solid-liquid extraction, next was the liquid-liquid extraction, then the sublimation and last was the melting point determination. The solid-liquid and liquid-liquid extraction were both done during the first meeting, the DCM layer was filtered and dried in the evaporating dish and kept inside the locker. The dried was light green, somewhat powdery flakes and was rough, this was purified through sublimation. The %yield of the caffeine was 0.11%. The last part was determining the melting point of the pure caffeine collected, standard started to melt at 220º and melted completely at 228º while the caffeine started to melt at 228º and completely melted at 231º.
Introduction
The objectives of the experiment are to a. isolate, purify and characterize caffeine from tea leaves and to b. calculate the percentage yield of caffeine.
The active ingredient in the tea and coffee is the caffeine, which is an alkaloid. Alkaloids contain nitrogen and have properties of an organic amine base. Caffeine has a mild stimulating effect on the central nervous system. Caffeine belongs to the family of xanthine, which is known as stimulants. Caffeine is the most powerful xanthine because of its ability to increase alertness, put off sleep and increase ones capacity for thinking. It also relaxes blood vessels and increases urination. Other than tea leaves, caffeine can also be found in coffee, cocoa beans and kola nuts. Tea leaves consist mostly of cellulose, caffeine, and a small amount of chlorophyll. The solubility of caffeine in water is 22 mg/ml at 25·C, 180 mg/ml at 80·C, and 670 mg/ml at 100·C. [1]
There have been several concerns about the health risks of caffeine, although scientists have already said that normal consumption
Marc Tugaoen, Kristine Vanzuela, Rafael Villanueva, Justeen Wong
Department of Chemistry, University of Santo Tomas, Manila, Philippines
Abstract
This experiment has been divided into 4 set-ups, first was the solid-liquid extraction, next was the liquid-liquid extraction, then the sublimation and last was the melting point determination. The solid-liquid and liquid-liquid extraction were both done during the first meeting, the DCM layer was filtered and dried in the evaporating dish and kept inside the locker. The dried was light green, somewhat powdery flakes and was rough, this was purified through sublimation. The %yield of the caffeine was 0.11%. The last part was determining the melting point of the pure caffeine collected, standard started to melt at 220º and melted completely at 228º while the caffeine started to melt at 228º and completely melted at 231º.
Introduction
The objectives of the experiment are to a. isolate, purify and characterize caffeine from tea leaves and to b. calculate the percentage yield of caffeine.
The active ingredient in the tea and coffee is the caffeine, which is an alkaloid. Alkaloids contain nitrogen and have properties of an organic amine base. Caffeine has a mild stimulating effect on the central nervous system. Caffeine belongs to the family of xanthine, which is known as stimulants. Caffeine is the most powerful xanthine because of its ability to increase alertness, put off sleep and increase ones capacity for thinking. It also relaxes blood vessels and increases urination. Other than tea leaves, caffeine can also be found in coffee, cocoa beans and kola nuts. Tea leaves consist mostly of cellulose, caffeine, and a small amount of chlorophyll. The solubility of caffeine in water is 22 mg/ml at 25·C, 180 mg/ml at 80·C, and 670 mg/ml at 100·C. [1]
There have been several concerns about the health risks of caffeine, although scientists have already said that normal consumption
References: [1] http://www.angelfire.com/blog/caffeinechem/ [2] http://www.spot.pcc.edu/~chandy/241/CaffeineExtractionCH2CCl2.pdf [3] http://www.scribd.com/doc/35716872/Extraction-of-Caffeine-from-Tea-Leaves [4 ]http://answers.yahoo.com/question/index?qid=20090721101813AALFlRu [5] Garcia, G. (2005). Laboratory Experiments in Organic Chemistry. University of Santo Tomas, Manila.