Science Practical 19

Extracting Chlorophyll

Apparatus:

2 beakers (one 50 ml and one 250ml)

Variegated leaf (placed in sunlight for 3-4 hours)

Methylated Spirit (Alcohol)

Iodine solution

White tile

Forceps/ Tongs

Bunsen burner

Tripod stand

Wire Gauze

*Ensure that there is no heat source that could ignite the methylated spirits as it is alcohol*

Procedure:

1. Boil 150ml of water in the 250ml beaker.

2. Place a soft leaf in the boiling water for 1 to 2 minutes to break the cell structure in the leaf.

3. Turn off and remove the heat source.

4. Place the boiled leaf in 20ml of methylated spirits in the 50ml beaker. Place the 50ml beaker into the 250ml beaker which has hot water inside.

5. Jiggle or agitate the leaf using tongs/forceps till the methylated spirits is deep green and the leaf is white. (The chlorophyll is now in solution in the methylated spirits)

6. Remove the leaf and transfer it to the beaker of hot water for a while.

7. Gently place the softened leaf on a piece of white tile. Add a few drops of iodine solution to cover the leaf.

Conclusion:

The chlorophyll was successfully extracted from the leaf as there was no starch on the leaf. (The iodine did not turn blue-black)