Question: What is chromatography?

Deborah Prunty answered on 16 Jun 2016:

Chromatography is the science of separating things into all the separate bits that make them up.

The type of chromatography that I use the most is called gas chromatography. A tiny bit of a liquid sample is injected in to instrument where it gets heated up until it turns into a gas. Its then blown through a really long really thin tube coated with sticky stuff. Different things stick to the inside of the tube different amounts, and so all the different bits get separated out. They then go through the detector at the end where they are burned. I look at how long things took to come out, and how much of them were there and work out what was in the original sample.