Inks, paints and foods often contain mixtures of coloured compounds. Chromatography can be used to find out which colourings are in those substances.
Some coloured compounds dissolve better in a solvent than others. They have different solubilities. This difference is used to separate different components of mixtures in chromatography.
In paper chromatography, samples are placed near the bottom of a sheet of special paper. Solvent then soaks up the paper. The different components of a mixture are carried by the solvent at different speeds so they are separated.…