Chromatography – lets get some separation

When substances are mixed together it is often very difficult to separate them out and see what is included in the mixture. Chromatography is one method in which you can separate mixtures and can help  solve crimes or mystery’s. It is a method often used in forensic science!

For example if someone left you a secret note and you suspected three people and they all had different pen, you could test the pens to see what colour dyes were included and then test the note, and see which one matched.

So without further ado, I will show you how to do chromatography. it is really very simple.

You will need some

Felt tip pens – cheap ones are best and brush tips work well

Coffee filter paper

Ruler and pencil

straw

Paperclip

Clear glass beaker

Water

Fun Sparks Chromatography - lets get some separation Science Sparks

Method

1. Open out the filter paper and using the ruler cut a straight strip about 10cm long (or as tall as your glass) and 4cm wide (this must be less than the width of your glass as the paper cannot touch the sides!)

2. 2cm up from your strip draw a faint line across in pencil.

3. Mark on three dots evenly across the line in three different colours

Fun Sparks Chromatography - lets get some separation Science Sparks

4. Fold the top of the strip over the straw and fasten with a paper clip

5. Test out the size in the glass – the straw should rest on the top and the sides should not touch the glass and the bottom of the filter paper should not be touching the bottom of the glass. Addjust how much paper is folded over if it is too long.

Fun Sparks Chromatography - lets get some separation Science Sparks

6. Fill the bottom of the glass with water, just enough to touch the bottom edge of the paper.

7. The water should absorb and seep up the paper.

Fun Sparks Chromatography - lets get some separation Science Sparks

We did it twice. Once with red, blue and green and once with yellow, pink and purple

This is the results of red blue and green.

Fun Sparks Chromatography - lets get some separation Science Sparks

You can see clearly that the green was made up of a turquoise blue and yellow, the dark blue was made of a turquoise blue and darker blue and the red was all one shade.

Her are the results for pink, purple and yellow!

Fun Sparks Chromatography - lets get some separation Science Sparks

The yellow is all one shade, the pink is made up of purple and red and the purple contains blue!

So have a go and see if you can do some detective work on your pens.

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