Paper chromatography.

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Biology Lab report

Title : Paper chromatography

Aim : to separate and identify of the pigments in leaves by paper chromatography

Principle of design:

In this experiment, a strip of filter paper containing a small spot of concentrated chlorophyll pigment is dipped in a mixture of developing solvent, the pigments was carried up the strip as the solvents move up. Since the solvents moved at different rates and pigments had different solubilities in them, the pigments gradually become separated. When the solvent was near the top of the paper, the paper was removed. After that, Rf (Relative front) for that substance were calculated. In this experiment, Rf values were used to identify the different substances present in the leaf extract mixture.

Instructions:

1. 3 leaves of spinach were ground in pestle and mortar by 2 cm3 of extraction solvent

2. the developing solvent was added into the boiling tube and it just touched the lower edge of the paper strip.

3. The tube was kept stopper to allow it to saturate with the solvent vapour

4. Both sides of paper strip were trimmed to make sure that the sides of