Isolation of Caffeine from Tea
Name: Date of Experiment: November 20, 2012
Group mates: Date of Submission: November 28, 2012 Experiment No. 1
ISOLATION OF CAFFEINE FROM TEA
I. Introduction Caffeine is a very common substance and is found in coffee, tea, soft drinks, chocolate, and "stay-awake" pills such as Vivarin. It can be synthesized or isolated from natural sources. Caffeine constitutes approximately 4% of tea and coffee leaves, and is also found in cola nuts and cacao beans. Caffeine is a member of the class of compounds organic chemists call alkaloids. Alkaloids are nitrogen containing basic compounds that are found in plants. They usually taste bitter and often are physiologically active in humans. Caffeine belongs to the family of heterocyclic compounds known as purines. It has the systematic name 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6-dione; it is also known as 1,3,7-trimethylxanthine, and 1,3,7-trimethyl-2,6-dioxopurine. Caffeine can be classified as an alkaloid , a term used for substances produced as end products of nitrogen metabolism in some plants. The chemical formula is C 8 H 10 N 4 O 2 . Caffeine has a molar mass of 194.19 grams (6.85 ounces). It is soluble in water and in many organic solvents, and it appears in pure form as white crystals. Caffeine can be prepared by extraction from natural sources or by synthesis from uric acid. The objectives involved in this experiment is to gain experience in using extraction as a method of separation, to assemble and use a simple distillation setup in the separation volatile substances from non-volatile materials, to determine the boiling pint of a liquid sample and to isolate caffeine from tea and gain experience in chemical laboratory manipulation of plant materials.
II Materials and Methods
The materials used in this experiment are the following: * * 10 pieces of tea bags(20 g) * 175 distilled water * 30 mL Chloroform (2 sets of 30 mL) * 12.5g Sodium Carbonate * Sodium
Group mates: Date of Submission: November 28, 2012 Experiment No. 1
ISOLATION OF CAFFEINE FROM TEA
I. Introduction Caffeine is a very common substance and is found in coffee, tea, soft drinks, chocolate, and "stay-awake" pills such as Vivarin. It can be synthesized or isolated from natural sources. Caffeine constitutes approximately 4% of tea and coffee leaves, and is also found in cola nuts and cacao beans. Caffeine is a member of the class of compounds organic chemists call alkaloids. Alkaloids are nitrogen containing basic compounds that are found in plants. They usually taste bitter and often are physiologically active in humans. Caffeine belongs to the family of heterocyclic compounds known as purines. It has the systematic name 3,7-dihydro-1,3,7-trimethyl-1H-purine-2,6-dione; it is also known as 1,3,7-trimethylxanthine, and 1,3,7-trimethyl-2,6-dioxopurine. Caffeine can be classified as an alkaloid , a term used for substances produced as end products of nitrogen metabolism in some plants. The chemical formula is C 8 H 10 N 4 O 2 . Caffeine has a molar mass of 194.19 grams (6.85 ounces). It is soluble in water and in many organic solvents, and it appears in pure form as white crystals. Caffeine can be prepared by extraction from natural sources or by synthesis from uric acid. The objectives involved in this experiment is to gain experience in using extraction as a method of separation, to assemble and use a simple distillation setup in the separation volatile substances from non-volatile materials, to determine the boiling pint of a liquid sample and to isolate caffeine from tea and gain experience in chemical laboratory manipulation of plant materials.
II Materials and Methods
The materials used in this experiment are the following: * * 10 pieces of tea bags(20 g) * 175 distilled water * 30 mL Chloroform (2 sets of 30 mL) * 12.5g Sodium Carbonate * Sodium
References: “Experiment #6 – Isolation of Caffeine from Tea Leaves”Retrieved November 27, 2012. http://employees.oneonta.edu/knauerbr/chem226/226expts/226_expt06_pro.pdf “Extraction Of Caffeine From Tea Leaves”Retrieved November 24, 2012. http://www.pharmainfo.net/reviews/extraction-caffeine-tea-leaves “Isolation of Caffeine from Tea and Purification by Sublimation”Retrieved November 24, 2012. http://www.scribd.com/doc/47708149/112A-Lab-2-Write-Up Microsoft® Encarta® 2009.