Chromatography
is a technique for separating coloured chemicals. The colour inks in each of
your felt tip pens is probably made of a mixture of different colours. Here is a
very simple experiment that you can do at home in your kitchen. Have a look at
the animation and then read the instructions underneath.
You will not have any special chromatography paper at
home, but you can use blotting paper of some kitchen towel. Cut a piece
about 10 to 15 cms long and 4 or 5 cms wide.
Put about 2
cms water in the bottom of a tall drinking glass. If your felt tip pens are
permanent you will have to use gin or vodka instead of water. If your fel tips
are washable then it will work with water.
Draw a thin pencil
line about 2 cms from the bottom of the piece of paper and mark some little
crosses on the line.
Make a little coloured dot on top of each
cross with a different coloured pen.
Hang the paper in the glass
so that it just dips into the water. Make sure that the water does not cover the
coloured dots.
After a bit a little while you should see the
water soaking up the paper. Watch what happens.
When the water
has reached the top, take it out. Mark the top of the water with a pencil line
and leave it to dry. The mark each coloured spot with a pencil ine at the
top.
Congratulations: you have made your first
chromatogram.
