Paper Chromatography EZ Method
Materials:
Scissors
cm Ruler
Filter paper strips
Tape
Fern fronds
Pencil
Graduated Cylinder
Isopropyl Alcohol
Notes:
Paper chromatography is a process that uses filter paper to separate
different substances in a mixture. Some of the substances applied to the
paper may dissolve in the alcohol and be pulled up the paper as the
alcohol travels up. Heavier substances move up the paper more slowly.
Lighter substances move up the paper more quickly. This causes heavy
and light substances to get separated from one another on the paper.
Procedures:
1. Use a filter paper strip that has been cut for you. Try to avoid
handling the strip since the oils from your skin can interfere with
your results.
2. About 2 cm from the bottom, draw a straight line in pencil using a
cm ruler. Place two fern leaflets horizontally across the strip just
barely above the pencil line.
3. Roll a coin with its edge firmly pressed down straight across the
fern leaflets. It is important to press firmly
4. Remove the fern leaflets. You should see a dark green band above
the pencil line. (If not, repeat step 3.)
5. Tape the top end of the strip to the middle of a pencil so that the
paper strip hangs down into the cylinder nearly touching the
bottom. (You may need to roll the strip around the pencil to adjust
the length.) Put the pencil with the strip aside.
6. Add 5 ml of alcohol to the cylinder.
7. Place the strip into the cylinder without immersing the green band.
Do not move the cylinder once the strip is inside.
8. After 15 minutes, when the alcohol nears the top of the strip,
remove the strip and examine carefully for pigment bands.
LS-21