EXTRATION OF CAFFEINE FROM TEA LEAVES

SYNONYM                           :Camellia thea

BIOLOGICAL SOURCE     : It consists of prepared leaves and leaf buds of ‘Thea sinensis belonging

                                              to family ‘Theaceae’.

CHEMICAL CONSTITUENTS:

*Tea leaves contains rich source of cfaffine (1-3%),Thea-1bromine and theophylline in major

   quantites.

*The colour of leaves is due to gallatanic acid.

*The aggreable colour is due to presence of yellow volatile oils.

*Tea leaves also contain enzymatic mixture ‘Thease’.

STRUCTURE:

CHEMICAL NAME:

          1,3,7 Trimethyl xanthine

USES:

          *Act as CNS Stimulant

          *Act as diuretic

IDENTIFICATION TESTS:

         

S.NO	EXPERIMENT	OBSERVATION	INFERENCE
1.	MUREXIDE TEST:To few mg of caffine,3-4 drops of potassium nitrate was added in a small porcelin dish.it was then evaporated to dryness.To the obtained residue,2 drops of Ammonium hydroxide.	Purple colour was observed.	Presence of caffine was confirmed.
2.	MAYER’S TEST: To few mg of caffeine mayer’s reagent was added.	No precipitate was observed.	Presence of caffeine was observed.
3.	To the test sample containing 0.2% of caffeine in chloroform was taken in procelein dish.It  was then evapourated to dryness to the residue,5 drops of 30% w/v hydrogen peroxide aqueoussolution and 5 drops of 1M hcl was added.Heated over dryness.To the residue 1 drop of ammonia solution was added.	No colour change from yellow-red to red violet.	Presence of caffeine was confirmed.

REQURIMENTS:

          *Beakers

          *PH PAPER

          *Glass rod

          *Tripod stand

          *Standard flask

          *Funnel

CHEMICALS:

          *Teadust

          *10% sulphuric acid

          *Chloroform or Dichloromethane

          *Activated charcoal

PROCEDURE:

          50gms of tea dust was taken and mixed with a pintch of sodium bicarbonate.

          To it 800ml of water was added and mixture was heated on water for 15 minutes.

          The solution was filtered and to the filtrate,lead acetate solution was added drop by drop till precipitate ceases and again the solution was filtered.

          To the filtrate dilute sulphuric acid was added till precipitation has occurred.

          To obtained filtrate 1gm of activated charcoal was added.

          The clear filtrate and then evaporated.To obtain filtrate crystalline needles of caffeine.

          To the product was air dried and percentage yield was calculated on dry weight basis.

REFERENCE:

          The approximate yield of silky needles of caffeine is 1gm and should be 1%.

REPORT:

          1.Caffiene was extracted from tea dust and yield was found to be 0.025 gms=25mg.

          2.Various chemical tests of caffeine were performed and reported.