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Hello, one of the big ideas in chemistry today is chromatography, a way of separating mixed-up

substances to analyze them or extract something useful. In its basic form, it's familiar to generations of school children from when they put a spot of ink at the bottom of a strip of paper,

dip it into water and then watch the pigments spread upwards revealing their separate colours, sometimes if you're lucky, like feathers on a bird of paradise.

With progressive discoveries over 200 years,

some fine tuning and an occasion at a bell prize,

chemists can now sift out the different molecules in just about any substance.

It's a process that has an essential role in many parts of modern life, the cleaning of drinking

water, in forensic science and in medical tests and in making pharmaceuticals.

With me to discuss chromatography are Andrea Sulla, Professor of Chemistry at University College

London, April Stolker, Professor of Chemical Sciences at

Dublin City University and Leon Baron, Senior Lecture in Forensic Science at King's College

London.

Andrea Seller, we've mentioned Paper and Nick, what's going on there and can you, is this, can you give

us that example of chromatography?

Well, this is one of those wonderful little experiments or demonstrations if you will that

everyone should do with their children I mean you know if you've never done this

before then what you really have to do is to get either some kitchen paper or

some blotting paper. I must say that

and just to explain to this is Andrea has decided to turn this studio in a

mini laboratory so he's all over the table which is not very big anyway I'll

...