Chemistry Project Report on Extraction and Determination of Caffeine in Tea Samples Contains in Caffeine

Submitted by:
Student of XII-Science (Chemistry)

Submitted to :
Lecturer in Chemistry
Sr. Sec. School

Project Report on "Extraction and Determination of Caffeine Contents in Various Tea Samples"

This project report is on "Extraction and Determination of Caffeine Contents in Various Tea Samples". Caffeine in Tea Samples - Extraction and Determination - Chemistry Experiment, Extraction of Caffeine from Tannic Acid Free Filtrate

Central Board of Secondary Education (CBSE)

Biology project report

Project Report Name : "Extraction and Determination of Caffeine Contents in Various Tea Samples"

Type : Experimental Project Report

"Extraction and Determination of Caffeine Contents in Various Tea Samples"

Introduction to the topic
Theory
Procedure
Calculations
Observations and Expected Errors
Results

Caffeine in Tea Samples - Extraction and Determination - Chemistry Experiment

Most popular drinks in India are “Tea and Coffee” As is the popularity of these drinks so is the contribution of India in their production. India has been the leading producer of tea.
Tea grows indeed, fertile & well drained soil. It require warm and moist climate throughout the year. Frequent showers, well distributed over the year ensures continuous growth of tender leaves. In India it grows mainly in low hills of Assam, Hills of Darjeeling and Jalpaiguri, Northern West Bengal and the hill of Nilgiri etc.
Tea also causes many harmful disease such as Diabetes, problems in nervous system, decrease in ADN secretion which causes increase in wine secretion and it has Nicotine which is a Stimulant.

Theory and Chemistry Experiment

Use difference in the solubility of caffeine and tannic acid in water and chloroform to separate them them from tea leaves.
Caffeine is much more soluble in chloroform than in water. But tannic acid is extensively soluble in water as well as chloroform.

Extraction of Water Soluble Components from Tea Sample - Step-I

Take about 100ml of distilled water in 250ml conical flask.
Add 5gm of tea and boil it for 4 to 5 minute. Then cool it and filter.
Repeat this process again with 100ml of distilled water and residual tea leave.
The filtrate in each case should be collected.
Now the wet tea samples may be dried in an over and weighted.

Removal of Tannic Acid from Filtrate - Step-II

The filtrate obtained in the first step is now boiled with 2-3 grm. calcium carbonate to get tannic acid, present in tea extract, frecipitated. On leaving it for ten minutes ppt. is obtained.
Filter the solution without disturbing the ppt carefully. The ppt should be transferred to filter paper only after all the filtrate is removed.
Tannic acid has been extracted in the form of calcium ternate which on treatment with hydrochloric acid give tannic acid.
The filtrate is now free from tannic acid and can be used to extract caffeine.

Extraction of Caffeine from Tannic Acid Free Filtrate - Step-III

Take tannic acid filtrate obtained in step 2(ii) and add 100 ml of chloroform in it in a separating funnel and allow it to stand for 10 minutes.
Again the same procedure as done in (i)
Mix if with the previous one.
From this chloroform extract, chloroform may be distilled or evaporated.

The pale green residue obtained is crude caffeine. Repeat this experiment with other brands of tea and record your observation in a tabular form.

Weight of tea used = W₁ grm.
Weight of Caffeine = W₂ grm.

Calculation :
Percentage of solute caffeine = W₁/W₂x 100

Calculations of Double Diamond

W₁ = 6 gm
W₂ = 0.7 gm

Percentage of caffeine = 0.7 / 6 x 100 = 11.6%

Calculations of Lipton Tiger

W₁ = 6 gm
W₂ = 0.8 gm

Percentage of caffeine = 13.3%

Calculations of Taj Mahal

W₁ = 6 gm
W₂ = 0.7 gm

Percentage of caffeine = 11.6%

Calculations of Red Label

W₁ = 6 gm
W₂ = 0.72 gm

Percentage of caffeine = 12%

Observation Table

Sr.No.	Name of Brand	W₁	W₂	%age of caffeine
1.	Double Diamond	6gm	0.7 gm	11.6
2.	Lipton Tiger	6gm	0.8 gm	13.3
3.	Taj Mahal	6gm	0.7 gm	11.6
4.	Red Label	6gm	0.72 gm	12.0

Experiment Results :

The tea sample of Double Diamond contain highest amount of caffeine and hence :-

Gives better taste than others.
Is more harmful for our health.

Precautions and Expected Errors :

Chloroform should not be smelt directly for a long time as it itself is toxic.
The measurement of weight of tea leaves and all extract should be precise.
The measurement of weight of tea sample and all extract should be precise.
The water used should be distilled.
Apparatus should be clean and dry.
No water should be added to any extract in between the experiment as it may get errors in calculation.
No prolonged heating should be done as water may evaporate in large quantity along with same volatile solutes.

Bibliography

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