Chromatography Research Paper

The next diagram doesn't show details of how the paper is suspended because there are too many possible ways of doing it and it clutters the diagram.

Sometimes the paper is just coiled into a loose cylinder and fastened with paper clips top and bottom.

The distance travelled relative to the solvent is a constant for a particular compound as long as you keep everything else constant - the type of paper and the exact composition of the solvent, for example.

The distance travelled relative to the solvent is called the R values because you are making a direct comparison just by looking at the chromatogram.

In paper chromatography, the stationary phase is a very uniform absorbent paper.

The mobile phase is a suitable liquid solvent or mixture of solvents.The left-hand diagram shows the paper after the solvent front has almost reached the top. The second diagram shows what it might look like after spraying with ninhydrin.There is no need to measure the R values because you can easily compare the spots in the mixture with those of the known amino acids - both from their positions and their colors.Some of the ink from the message is dissolved in the minimum possible amount of a suitable solvent, and that is also spotted onto the same line.In the diagram, the pens are labeled 1, 2 and 3, and the message ink as M.You probably used paper chromatography as one of the first things you ever did in chemistry to separate out mixtures of colored dyes - for example, the dyes which make up a particular ink.That's an easy example to take, so let's start from there.They all have a stationary phase (a solid, or a liquid supported on a solid) and a mobile phase (a liquid or a gas).The mobile phase flows through the stationary phase and carries the components of the mixture with it. We'll look at the reasons for this further down the page.Chromatography is used to separate mixtures of substances into their components.All forms of chromatography work on the same principle.