Eli5: How does chromatography work?



* How does it separate a mixture ?
* Does it separate something to all of it’s core components?
* Can we use it to break down the core components to their core components?

In: Chemistry

Chromatography will seperate chemicals, not break the chemicals down into their individual molecules. It is not a chemical reaction. The concept is that as a solvent is passed along the substance in question, the solvent will “drag” the unknown with it some percentage of the distance or speed of the solvents total. The most basic way to see this is used is used in early chem labs. You can put drops of unknown solutions on a paper, gently roll the paper up and place it in a jar of a known solvent. The dots are not submerged in the solvent and as the solvent creeps up the paper it will drag with it the unknowns. If there are 2 unknowns in the same sample, and the solvent has ratios that differ to each of those unknowns they will move along the paper at different rates, thus seperating them and allowing further analysis.

So there are different types and techniques of chromatography, but they all work by the same priciple.
Separating a substance into its components by using their different properties.

A substance that’s composed of multiple components moves across a surface that has a certain property, let’s say a positive charge. If all components of the substance have a different charge (different in strength and + or-) they will be attracted to the surface to different degrees. A strongly negatively charged component would stick to the surface, whereas a positively charged component would travel further along with the substance it comes from.

I hope this helped, it’s very hard to explain this in a way a five year old would understand.