# Lab Report - Photosynthesis

LAB REPORT – CHROMATOGRAPHY                                                                       Chamodi Basnayake
PROCEDURE:
1. Cut out a piece of chromatography paper and draw a parallel line about 2 cm from the bottom of the paper using a pencil.
2. Use a coin to extract the pigments form the spinach leaf by, placing the leaf on the line drawn previously and using the edge of the coin to squeeze out the juice onto the paper leaving a band of about 3mm wide.
3. Use a 50ml beaker; pour acetone into the beaker, until it reaches about 1 cm from the bottom of the beaker.
4. Place the chromatography paper in the beaker making sure the line drawn does not touch the solvent.
5. Let the liquid move up the paper by osmosis, carrying the cell pigment upward with it.
6. Let it be there for 20 minutes or so and put an end to the experiment when acetone doesn’t seem to move any further along the paper.
7. Mark the maximum distance acetone travelled and the other pigment bands that had different colors.

Band Number | Distance Travelled(cm) | Band Color | Identity |
1 | 2.2 | Orange | Carotenoid |
2 | 2.3 | Dark Green | Chlorophyll A |
3 | 2.4 | Light Yellow | Xanthophyll |
4 | 2.6 | Light Green | Chlorophyll B |
Maximum Distance the Solvent (Acetone) moved = 2.8 cm |

PROCESSING THE DATA

Calculating the Rf Values
Rf= Distance traveled by PigmentDistance traveled by Solvent

MOLECULE | Rf |
1. Carotenoid | 0.79 |
2. Chlorophyll A | 0.82 |
3. Xanthophyll | 0.86 |
4. Chlorophyll B | 0.93 |
Example Calculations:
Rf=yx   ; y = Distance pigment travelled;       x = Distance Solvent travelled
Chlorophyll B:
Y = 2.6; x = 2.8
Rf=2.62.8
* 0.93

Chlorophyll A:
Y = 2.3; x = 2.8
Rf=2.32.8
* 0.82

Xanthophyll:
Y = 2.4; x = 2.8
Rf=2.42.8
* 0.86

Carotenoid:
Y = 2.2; x = 2.8
Rf=2.22.8
* 0.79

CONCLUSION:
Paper chromatography is a technique used to separate substances in a...