Chromotography

- Can be used to seperate complex organic molecules such as plant pigments or amino acids

1). Handle the paper using gloves

2). Draw a line of orgin, and for amino acids, in pencil 

3). Spot the amino acids using a fine needle and concentrate by repeated application

4). Add solvent to tank, approx 1cm, and allow atmosphere to become saturated with the solvent vapour

5). Add chromatography paper ensuring its edges don't touch the sides

6). Allow the solvent to run apporx. 1cm from the top

7). Remove the chromatogram from the tank and mark the solvent front in pencil

8). Dry the chromatogram and spray with ninhydrin

9). Dry the ninhydrin and heat in an oven to develop the stain

10). Measure the distance of the solvent front and mark the midpoint of each spot

11). Rf value for each spot is calculated and identification of amino acids can be made 

Chromatography of plant pigments

When plant leaves are crushed in a mortar, the pigments in the cholroplasts are released. These proteins can be dissolved in a suitable orgainc solvent and then seperated using chromatography. The results should reveal the presence of several pigments in order to faciitate the absorption of light over a range of wavelenghts.