RP07 - Chromatography of photosynthetic pigments

Question 1

What is the purpose of chromatography

Answer 1

To separate different components in a sample

Question 2

State the factors affecting the rate of migration of different pigments

Answer 2

• Solubility
• Mass
• Affinity to paper

Question 3

Formula for Rf value

Answer 3

Distance moved by pigment/distance moved by solvent

Question 4

What is the purpose of finding the RF value of pigment

Answer 4

• Can be compared to standard database value to identify the pigment

Question 5

Outline the procedure of using chromatography to separate photosynthetic pigments

Answer 5

1. Draw a horizontal pencil line 1cm above the filter paper
2. Add acetone and grind leaf sample to release the pigment
3. Use the capillary tube to transfer the pigment onto the pencil line
4. Suspend the paper line and leave paper until solvent line has ran to NEAR the top
5. Remove the paper from the solvent and draw a pencil line marking where the solvent moved up to
6. Calculate the Rf value for each spot