caffine contents in tea samples

8/11/2019 caffine contents in tea samples

1/16

1

Know How much caffeine you aretaking in with each cup of tea!

Project Prepared By:

Ankit BahugunaXII-ARoll Number:Lovely Public Sr. Sec. School (P.D. Vihar)

iC S

E co

m


2/16

2

First of all I would like to thank my cousin brotherMr. Neeraj Naithani Research Scholar Departmentof Chemistry, IIT Roorkee for his contribution in thisstudy. I would also like to thank my ChemistryTeacher Ms. Rampal in providing a helping hand inmaking my project titled Determination OfCaffeine In Tea Samples .

Disclaimers: The errors idiocies and inconsistenciesremain my own.

Ankit Bahuguna(Name and signature of the student)

iC S

E co

m


3/16

3

It is hereby certify that, theoriginal and genuine research

work is carried out to investigate

abut the subject matter and therelated data collection and hasbeen completed solely and

satisfactorily by this studentregarding the Project titled

Determination Of Caffeine In TeaSamples .

Signature(Subject Teacher)

iC S

E co

m


4/16

4

CONTENTS1. Introduction2. Theory3. Uses of Caffeine4. Effects of Caffeine

5. Procedure6. Observations7. Result

iC S

E co

m


5/16

5

INTRODUCTION

Tea is the most commonly and widely usedsoft beverage in the household. It acts as astimulant for central nervous system andskeletal muscles. That is why tea removesfatigue, tiredness and headache. It alsoincreases the capacity of thinking. It is also

used for lowering body temperature. Theprincipal constituent of tea, which isresponsible for all these properties, is thealkaloid-caffeine. The amount of caffeine intea leavers varies from sample to sample.

Originally it was thought that caffeine isresponsible for the taste and flavour of tea.But pure caffeine has been found to be atasteless while substance . Therefore, thetaste and flavour of tea is due to some other

substance present in it. There is a littledoubt that the popularity of the xanthenesbeverages depends on their stimulantaction, although most people are unaware

iC S

E co

m


6/16

6

of any stimulation. The degree to which anindividual is stimulated by given amount of

caffeine varies from individual toindividual.

For example, some people boast theirability to drink several cups of coffee inevening and yet sleep like a long, on the

other hand there are people who are sosensitive to caffeine that even a single cupof coffee will cause a response boarding onthe toxic.

The xanthene beverages also create amedical problem. They are dietary of astimulant of the CNS. Often the physiciansface the question whether to deny caffeine-containing beverages to patients or not. Infact children are more susceptible than

adults to excitation by xanthenes.

For this reason, tea and coffee should beexcluded from their diet. Even cocoa is of

iC S

E co

m


7/16

7

doubtful value. It has a high tannin contentmay be as high as 50 mg per cup.

After all our main stress is on the presenceof caffeine in xanthene beverages and so inthis project we will study and observe thequantity of caffeine varying in differentsamples of tea leaves.

iC S

E co

m


8/16

8

Theory

The most important methylated alkaloidthat occurs naturally is caffeine. Itsmolecular formula is C8H 10N4O 2. Its IUPACname is 1, 3, 7-trimethylxanthene andcommon name is 1-methylatedthiobromine .

iC S

E co

m


9/16

9

Purely it is white, crystalline solid in theform of needles. Its melting point is 123 0c. It

is the main active principle component oftea leaves. It is present in tea leaves up to3% and can be extracted by first boiling thetea leaves with water which dissolves manyglycoside compounds in addition tocaffeine. The clear solution is then treated

with lead acetate to precipitate theglycoside compounds in the form of leadcomplex. The clear filtrate is then extractedwith extracts caffeine because it is moresoluble in it then water.

iC S

E co

m


10/16

10

Uses of Caffeine :

1. In medicine, it is used to stimulate,central nervous system and to increaseflow of urine.

2. Because of its stimulating effects,caffeine has been used to relieve fatigue.

But it is dangerous and one maycollapse if not consumes it under certainlimit.

3. Caffeine is also used in analgesictablets, as it is believed to be a painreliever. It is also beneficial in

migraines.

iC S

E co

m


11/16

11

Effects of Caffeine

1. It is psycho - stimulant.

2. It improves physical and mental ability.

3. Its effect in learning is doubtful but

intellectual performance may improvewhere it has been used to reduce fatigueor boredom.

4. When administered internally, itstimulates heart and nervous system

and also acts as diuretic. On thecontrary their excessive use is harmfulto digestion and their long use leads tomental retardation.iC

S

E co

m


12/16

12

Procedure First of all, 50 grams of tea leaves

were taken as sample and 150 ml ofwater was added to it in a beaker.

Then the beaker was heated up toextreme boiling.

The solution was filtered and leadacetate was added to the filtrater,leading to the formation of a curdybrown coloured precipitate.

We kept on adding lead acetate till nomore precipitate has been formed.

Again solution was filtered. Now the filtrate so obtained was

heated until it had become 50 ml. Then the solution left was allowed to

cool.

After that, 20 ml. of chloroform wasadded to it. Soon after, two layers appeared in the

separating funnel.

iC S

E co

m


13/16

13

We separated the lower layer. The solution then exposed to

atmosphere in order to allowchloroform to get evaporated. The residue left behind was caffeine . Then we weighed it and recorded the

observations.

Similar procedure was performed withdifferent samples of tealeaves and quantityof caffeine was observed in them

iC S

E co

m


14/16

14

1.Red Label Tea (Brooke Bond)

Weight of china dish 46.60gmsWeight of china dishwith precipitate

47.20gms.

Amount of caffeine 0.60gms

222. ..YYYeeel lllllooowww LLLaaabbbeeel ll TTTeeeaaa ( ((LLLiiippptttooonnn)))

Weight of china dish 46.60gmsWeight of china dishwith precipitate

47.15gms.

Amount of caffeine 0.55gmsiC S

E co

m


15/16

15

333. ..GGGr rreeeeeennn LLLaaabbbeeel ll TTTeeeaaa ( ((LLLiiipppt ttooonnn)))

Weight of china dish 46.60gms.Weight of china dishwith precipitate

47.05gms.

Amount of caffeine 0.45gms.

1. Quantity of caffeine in Red label teais 60mg. /sample of 50 gm.

2. Quantity of caffeine in yellow labeltea is 55mg./sample of 50 gm.

3. Quantity of caffeine in green label teais 45mg./sample of 50 gm.

iC S

E co

m


16/16

16

Graphically plotting various tea samples inaccordance with the amount of caffeine

present in them we present a stunning find:

0

0.1

0.2

0.3

0.4

0.5

0.6

60 mg 55 mg 45 mg

RED LABEL YELLOW LABEL GREEN LABEL

Order of quantities of caffeine indifferent samples of tealeavesiC

S

E co

m

Documents

caffine contents in tea samples