Simplest Chromatography Experiment

Smarties are colored using different dyes, which can be separated by chromatography. Find out which colors are made up of the most dyes and then eat the smarties!

Material:

• Tube of Smarties
• Blotting or filter paper

Method

1. Place a smartie in the center of a circle of blotting paper
2. Slowly drip water onto the smartie until a 5 cm wet patch surrounds it
3. Leave until all the components of the dye have separated
4. Eat the now white and soggy smartie

Why does this work?

In lots of cases, a dye is made up of several different colors all mixed together. Chromatography is a really clever method used to separate the components of a sometimes complex mixture. In this experiment we used paper chromatography. You will have noticed that the wet area on the paper spread and got bigger throughout the experiment - this is due to capillary action pulling the water through the pores in the filter paper. The dye molecules are divided between the solid phase (the paper) and the liquid phase (the water). Depending on their size and solubility they will travel with the water faster or slower through the paper and will therefore travel different distances during the experiment. You can try the same experiment with ink and could even try other colored substances although I'm not promising that this will work as well as the smarties!