Chromatography
Aim: To separate the different colours in food colouring using chromatography.
Apparatus:
 2 Beakers
 Long strips of highly absorbent paper
 Food colouring
 Methylated spirits
 Water
 Pen
Method:
1. Put a little bit of water in one beaker and a bit of methylated spirits into the other beaker.
2. Make a very small but intense dot low down on a strip of absorbent paper.
3. Place the absorbent paper so it just dangles in the liquid using a pen.
Results:
 The primary colours didn’t split but green was very successful and went a long way up
the paper and you could easily see blue and yellow.
Conclusion:
1. We tested green (very successful, green and blue), red (only one colour) and blue (also
only one colour).
2. The colours have different solubilities and therefore as the different pigments dissolved in
the water they broke of at different points because of their solubility.