Chromatography Method

1. A pencil is drawn on the chromatography paper near the bottom. Pencil is used as it will not dissolve in the solvent.

2. Small amounts of the substances being analysed are placed in spots on the pencil line.

3. The paper is hung in a beaker of the solvent. The pencil line and spots must be above the level of the solvent so that the spots do not dissolve into the solvent in the beaker.

4. Over the next few minutes, the solvent soaks up the paper.

5. When the solvent is near the top, the paper is taken out of the solvent and the level of solvent reached is marked. This is known as the solvent front.

6. The paper is left to dry.

1. 1.     The sample is dissolved in a solvent, then injected into one end of the column.

   2.     An unreactive gas - usually nitrogen - carries the sample through the column.

   3.     Different substances in the sample travel through the column at different speeds and so become separated from each other.

   4.     The separated substances leave the column one after the other. As they leave, they are detected by a detector.