Column Chromatography

E- Numbers
S3 Chemistry Mini-Assignment
What are E- Numbers
• E numbers are codes for chemicals which can be used as food
additives for use within the European Union (the "E" prefix
stands for "Europe").
• They are commonly found on food labels throughout the
European Union.
• Having a list for food additives was first agreed upon in 1962
with colours.
• In 1964 the directives for preservatives was added, 1970 for
antioxidants and 1974 for the emulsifiers, stabilisers,
thickeners and gelling agents.
In this assignment we will investigate the E –Numbers
relating to colouring agents to foods.
• E- Numbers from E 100- E199 are related to colour.
• Some sweets and other food stuffs gain certain colours
by mixing E- Numbers.
• Think, how many E-Numbers must one packet of m&
m’s contain.
• Different E- Numbers are used to gain different colours
e.g. E129 – allura red
• It is essential people are made aware of the E- Numbers
contained in their foods for many reasons.
Reasons to Avoid E-Numbers
• If you already suffer from asthma or any other
form of breathing problem there are some E
numbers that could make your condition worse.
• Some people may be allergic to certain Enumbers.
• Some E -numbers may cause stomach upset.
• Some of the E -numbers that the UK government
have suggested children should avoid, particularly
if they’ve shown any signs of suffering from
hyperactivity, are as follows.
Due to this….
• It is essential chemists can separate coloured
substances into their different E- Numbers.
• Once separated chemists can identify certain
E- numbers and research the health effects
these E- Numbers may cause.
When doing your own research, you
must research the following ENumbers
Allura Red (E 129)
Brilliant Blue (E 133)
Quinoline Yellow (E 104)
Sunset Yellow (E 110)
Green S (E 142)
Carmine (E120)
Chromatography is a technique used to separate a mixture
There are two phases in Chromatography:
1. Mobile phase
2. Stationary phase
The mobile phase flows through the stationary phase and
carries the components of the mixture with it.
The different components travel at different speeds.
Think of Chromatography as a race .......
Waiting at the starting
line, you have a mixture of
chemicals. Just like the
runners waiting to start.
When the race starts, the
runners spread out because
they have different abilities.
In exactly the same way the chemicals in the liquid mixture
spread out because they travel at different speeds over
the stationary solid.
Smaller, more soluble molecules will travel through the
stationary phase faster and will be identified first.
Bigger, less soluble molecules will travel through the
stationary phase slower than smaller molecules and will be
identified last.
Packing the Column
5. Insert the plunger and press to
force the water through.
4. Add 2-3cm3 of distilled water.
3. Insert another plug of mineral
wool. Insert the plunger, press
down firmly and remove.
2. Add talc to roughly 8cm3 line.
Insert the plunger to ensure the
talc is fully compressed.
1. Insert a loose plug of mineral wool
into the syringe.
Extracting the Dye
1. Add 5 ml of distilled water to a
2. Put two sweets (of the same
colour) into the water.
3. Once the dye has dissolved,
remove the sweets from the
4. Put the mixture aside, this will be
used later.
Running the Column
1. Add 0.5cm3 of the extracted dye using
a pasteur pipette.
2. Put a layer (a few mm) of fine sand on
top of the dye.
3. Fill the syringe to 10cm3 with
distilled water.
4. Insert the plunger and apply pressure.
Collecting the Dyes
1. To start with, let the liquid drip into a
beaker. Watch very carefully for the
first signs of colour.
2. When you see the first hint of colour,
start collecting in the first test tube.
3. When you see the colour changing,
start collecting in a second test
4. Each colour should be collected in a
different test tube.
5. If the syringe runs dry add more
distilled water and continue.