Extraction of Caffeine from Tea

Q1)- Green about this experiment: According to GCP#3 i.e. Less hazardous chemical synthesis: extraction of crude caffeine pose little toxicity to human health and the environment.(1)

Q2) Things not green:

According to GCP# 5 i.e. Safer solvent and auxiliaries: In liquid-liquid extraction of caffeine, Dicholoromethane was used which is a hazardous chemical and have potential acute health effects(2). According to GCP#12 i.e. Inherent safer chemistry for accident prevention: The separatory funnels used in the experiment for liquid-liquid extraction was a dangerous procedure. Using Ch2Cl2 for liquid-liquid extraction produces gas within the funnels and if not taken care it can end in an accident.

Q3) How experiment be made greener?

Experiment could be made greener by implementing a method which can generate less amount of waste and give high yield of the desired sample.

Q4)

Percent yield= (the actual dry weight of caffeine obtained)/(weight of caffeine should have obtained) X100%

Mass of 100ml round flask (without caffeine)=67.05g
Mass of 100ml round flask (with caffeine)=67.08g
Therefore the mass of caffeine is=0.03g

Weight of 2 tea bags =6.63g
Mass of tea in those bags (excluding white bag each of 0.12g)= 6.63-(0.12*2)=6.39g

Percent yield = 0.03g/(6.39g ) X100%

Therefore the percent yield =0.47%

Q5)

K= SB/SA =0.42(given)
Weight of kryptonite=2.0g = 0.42/(0.42+2)= 0.1735 or 17.35% similarly, 2g/2.42=0.826 =82.6%

First Extraction, with 100ml fresh Solvent B:

17.35% of the 2.0g= 0.347 g of Kryptonite will transfer into solvent b layer.

82.6% of the 2.0g =1.652 g of kryptonite will be left in solvent A for the next extraction.

Second Extraction, with 100ml fresh solvent B

17.35% of 1.652 g = 0.287g goes into organic layer and is separated.

82.6% of 1.652g= 1.36g is used for the third extraction.

Q5b) K= SN/SM=12.7

Weight of Dubdeefordy = 4.7g

=(12.7/4.7+12.7)= 0.73=73% , similarly,=