Brenna FerrellPaper chromatographyis an old laboratory technique which is still used today. It is a way of separating pigments found in plants, cloth, dyes, inks etc. Paper chromatography has two 'phases'. These are actual physical things not time phases. The stationary phaseof the experiment is the paper itself; it doesn't move so it is stationary. The mobile phaseis the liquid that will move up the paper. It does not have to be moving to be the mobile phase. Different pigments require different mobile phases. For example if you wanted to separate the pigments from purple cabbage, you would have to use water as your mobile phase.The leaves change in the autumn because the dominant pigment found in leaves (chlorophyll) is breaking down, and the accessory pigments (carotenes, xanthophylls) can now be seen. Using paper chromatography these accessory pigments could have been separated out so they could be seen even though the chlorophyll was still present.