Chromatography

Chromatography

In chemistry, chromatography is a process for separating different components from a mixture. This is achieved by passing a sample mixture - the scientific word for this being analyte - in a stream of solvent through some form of material that will provide resistance when chemical interactions are made.  I read some where that this is an interreaction not a reaction.   Anyway, this happens between the components of the sample and the material.

Paper chromatography

Get a strip of kitchen roll. At one end put a blob of colour using a felt tip about 1cm away from the end.  Let a bit of the strip of kitchen roll touch the water so it gradually creeps up the paper.

As the water rises through the paper it then meets with the ink.  It will then start to travel up the paper with the water.  Different compounds in the ink travel different distances according to how strongly they interact with the paper. If done properly paper chromatography takes some time and the experiment is usually left to complete for some hours.  If you use felt tip pens I find that the results happen quite quickly.  My favourite colour to try is black but try different colours and see how they vary.

These are a few photos from our last experiment with chromatography!