2. Take a 500 ml beaker add 200 ml of 20°C distilled water to it. Now place 5 tea bags in this beaker.
3. Boil the content in a beaker, in a 40°C hot water bath for 5 minutes.
4. Pour the mixture into a new beaker.
5. Gently squeeze the tea bags (you can use a teaspoon to help when using high temperature of water) to make sure that all the water is in the beaker.
6. Cool the aqueous solution in an ice bath, use a thermometer to make sure that the temperature of the tea is 20° C (When using 20° C hot water bath there is no need to cool it down – skip step 6)
7. Extract the solution with a 30ml portion of dichloromethane (CH2Cl2). SAFETY CONCERN - Do not get dichloromethane …show more content…
Pour the tea solution into a separating funnel.
b. Add 20ml of dichloromethane is added to it. (observe separation of the mixture into two layers, bottom layer dichloromethane, top layer tea due to the fact that it has a lower density )
c. Remove the funnel from the stand and keep your fingers on the stopper and carefully shake the separating funnel.
d. Vent the separating funnel periodically (every 30 sec) to relieve vapour pressure created inside the funnel.
e. When the contents have been sufficiently shaken place the separating funnel back on the ring stand and let the two layers separate.
f. Drain the bottom layer into a conical flask because now the caffeine is extracted into the dichloromethane layer. Cover the mouth of the conical flask to avoid evaporation of the solution.
9 Dry the combined dichloromethane solutions using drying agent - anhydrous Sodium sulfite. Add 1 teaspoon to the solutions until it no longer clumps together at the bottom of the flask. Mix well and leave it for 10 minutes.
10 Pour the dichloromethane into a conical flask (100ml).
11 Let the solvent - dichloromethane evaporate in a hot water bath.
12 When all the solvent is removed there will be left yellowish green - white crystalline