Science@CSCB
Introduction to Chromatography
What is Chromatography?
Derived from the Greek word Chroma
meaning colour, chromatography provides a
way to identify unknown compounds and
separate mixtures
Applications of Chromatography
Forensics
Research
Pharmaceutical industry
Types of Chromatography…
Thin layer
Paper
HPLC
Gas
Column
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)
Thin Layer Chromatography
 Sample – marker
 Standard – food dyes
 Stationary phase – chromatography paper
 Mobile phase - water
Structures of E numbers…..
E122 pink
E110 yellow
E124 red
E133 blue
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
Calculation of results
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
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