2. What is Chromatography?
Derived from the Greek word Chroma
meaning colour, chromatography provides a
way to identify unknown compounds and
separate mixtures
5. Your mission should you choose
to accept is to……..
Analyse coloured markers
Test whether they contain E133 (blue), E122
(pink), E124 (red) or E110 (yellow)
6. Thin Layer Chromatography
Sample – marker
Standard – food dyes
Stationary phase – chromatography paper
Mobile phase - water
7. Structures of E numbers…..
E110 yellow
E122 pink
E124 red E133 blue
8. So what will happen?
Each dye will travel up the paper at different
speeds
The speed depends on the solubility of the dye in
water and its interaction with the paper
The dyes are all different molecules with different
characteristics
10. Calculation of results
Analysis
You must now calculate an Rf value for each spot.
Rf = Distance from the start to the middle of a spot
Distance from start to finish point of the water
11. Conclusions – writing up
One of the key elements of all scientific
experiments is to write up your results
At the end of this experiment we would like each
person to conclude from the Rf values as to which
E numbers are contained in the markers
