Pigment Chromatography Lab
Sahar Rudgar
Mr. Wright
SBI4U- Per. 4
Tuesday Mar. 22nd, 2005
Purpose: Separation of plant cell pigments by paper chromatography.
Materials:
- Chromatography paper
- Scissors
- Test tube
- Chromatography tube and solvent
- Pencil
- Fresh leaf
Procedure:
- A test tube was obtained containing developing fluid (9 volumes of petroleum ether / 1 vol. acetone) and a stopper with a hook.
- A 15 centimeter strip of Whatman chromatography strip was cut.
- One end to a point was trimmed with scissors. A pencil line was drawn just above the point.
- The strip on a hard clean flat surface was laid. A fresh leaf was put over the paper and the tissue was crushed onto the pencil line by rolling the edge of a test tube along the leaf surface. The leaf was moved and this was repeated several times. The line of pigment which has been crushed onto the paper was kept as thin as possible.
- The paper was immediately hooked onto the hook of the tube stopper so that the tip of the paper was immersed in the developing fluid. The paper was hanging vertically and not touching the sides of the tube.
- The tube stood for about 10 minutes. The movement of the solvent front was observed. When the solvent front was within one centimeter of the hook the paper was removed and a pencil line was drawn at the edge of the front (This was done quickly before it evaporated!).
- The distance that each pigment band traveled was measured from the bottom pencil line to the middle of the pigment band. The distance that the solvent front moved was measured. The migration rate (Rf value) was calculated for each pigment.
