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Hello friends welcome to the channel solution in this video we will show you the procedure to isolate caffeine from tea leaves for this we have taken photograph tulips in a beaker of capacity 500 ml and then added 6 gram of anhydrous sodium carbonate then add about 300 ml of distilled water to this tea leafs in a beaker and then mix the leafs distilled water and
Sodium carbonate with the help of glass rod now place the beaker in the heating mantle and boil it the content of the beaker for about 10 to 15 minutes here we have added sodium carbonate sodium carbonate which is basic in nature and this sodium carbonate combines means react with the tannin which is present in the tea and this tenon is acidic enough to combine
Means react with the base that is sodium carbonate and formed tannin salt and due to this means the formation of tannin solve the solubility of tannin increases in the water phase and later when we add organic phase to the aqueous extract for the isolation of caffeine the tannin will not get dissolve into the organic phase myth means tannin will remain in the
Upper space so that we can easily isolate the caffeine means we can easily isolate without any difficulty after boiling the tea leaves then first filter it means filter the content of the beaker with the normal tea filter and after filtration keep the filtrate aside and the residue of the tea leaves again add sufficient quantity of water in a beaker and then
Again boil filter and after filtration collect the filtrate and then combine both the filtrate in one beaker after combining both the filtrate again filtered this extract with the normal filter paper to remove the small particles this process will take time miss normal filtration with the normal filter paper will take more time to filter so you can use vacuum
Filter for the filtration if you are having vacuum filter then prefer vacuum filter for the rapid filtration after filtration collect the filtrate and then transfer the filtrate into separating funnel and then add ten ml of dichloromethane or you can use chloroform if you are not having dichloromethane the solubility of caffeine is more in dichloromethane means
In dichloromethane caffeine is more soluble as compared to water so the caffeine which is present in the aqueous phase on adding dichloromethane the caffeine leaved the aqueous phase and comes to the organic phase that is dichloromethane layer at the lower face of the separating from them here you can see that the dichloromethane layer and the aqueous layer
Gets separated means both immiscible layer get separated and mix both the layer by agitating the separating funnel very gently after stopper the separating funnel agitate the separating funnel in upward and downward direction as you can see in the video do not shake the separating funnel vigorously because if we shake the separating funnel vigorously then both
The layer get mixed and form emulsion so we have to shake the separating funnel gently to make smooth the layer in between agitation open the knob of the separating funnel to release the vapor pressure of the solvent build up inside the separating funnel and then again close the knob tightly after releasing the vapor pressure and again start the agitation after
Agitation clamp the separating funnel to the stand and after few minutes means when the two immiscible layer gets separated now we have to collect the lower layer of dichloromethane because in this dichloromethane layer caffeine is present for this open the knob and collect the lower layer in the empty clean beaker lower layer means dichloromethane layer and
Open the north such that the liquid will flow drop by drop only after collecting the dichloromethane layer into the beaker close the norm and again repeat the same process means again we have to add 10 ml of dichloromethane to the separating funnel and again agitate the layer gently to mix the liquid layer and then again allowed to separate the layer and then
Collect the lower layer man means dichloromethane layer this repeat this process for about three to four times after repeating this process three to four times and collect the and come all the fractions of lower layer means dichloromethane layer in a beaker and transfer all the clear dichloromethane liquid layer containing caffeine into the tradition covered
The petri dish with the perforated aluminum foil now for the evaporation of the solvent completely keep this petri dish aside for about few hours and allow the solvent to evaporate at room temperature after the evaporation of the solvent means dichloromethane and removed the aluminum foil from the petri dish and then observe the needle shaped crystal inside the
Petri dish and this needle shaped crystal is the crystal of caffeine now you can collect this caffeine from the petri dish and then recrystallize to get pure caffeine thank you very much for watching this video if you like this video then please subscribe our channel solution thank you
Transcribed from video
Extraction and Isolation of Caffeine from Tea Leaves (English) By Solution Pharmacy By Solution- Pharmacy
