RP12 - Separation of a species by Thin Layer Chromatography

Question 1

Chromatography separation of Amino Acids

Question 2

How to prepare capillary tubes?

Answer 2

Heat and pull quickly, then cut down to size using a heatproof mat

Question 3

Describe how we would carry out TLC to find amino acids?

Answer 3

1. Collect a piece of rectangular chromatography paper
2. lay the chromatography paper landscape on to a clean sheet of normal paper and draw a line in pencil 1.5 cm away from the bottom line.
3. fold the paper in half and then unfold. Mark in pencil five crossings on the baseline. Each mark is for each amino acid and mixture of amino acids
4. Use a capillary tube to apply a small amount of amino acid to the correct cross. dry and repeat this 5 times
5. Preparing the solvent: 4cm3 of butan-1-ol, 1cm3 of glacial ethanoic acid and 2cm3 of water. Cover the beaker to prevent solvent evaporation and to saturate the beaker with solvent vapour.
6. Place the folded chromatography paper into the beaker. Cover the beaker using a watch glass and leave flat on the table undisturbed for at least 30 minutes
7. Developing the chromatogram; remove chromatography paper from the solvent and using a pencil mark the solvent front. dry paper using a hair dryer.
8. In a fume cupboard detect the amino acids by spraying ninhydrin solution onto the chromatogram
9. remove paper from the cupboard and place on a hot plate for a couple minutes to develop - purple spots should appear indicating the presence of AA.

Question 4

Finished