Chromatography can be used to seperate out dyes in a sample of ink.
- Spots of dye are dropped onto a baseline on a square of filter paper.
- The sheet is rolled up and placed in a beaker containing shallow solvent.
- The solvent seeps up the paper, taking the dyes with it.
- Each different dye in the ink samples will form a distinct spot on the paper.
- It is now possible to compare the unknown ink to known dyes.