1) A drop that contains a mixture of four amino acids was applied to a thin layer chromatography plate. The plate was placed in solvent G and the following chromatogram was obtained.

The Rf values for each of the amino acids in solvent G are provided in Table 1 below.

Name the amino acid that corresponds to spot 1.

Solution

2) The plate was dried, rotated through 90° in an anticlockwise direction and then placed in solvent F. The Rf values for
each of the amino acids in solvent F are provided in Table 2 below.

The following chromatogram was obtained.

a) Circle the spot on chromatogram II that represents alanine.

Solution

b) Explain, in terms of the data provided, why only three spots are present in chromatogram I while four spots are
present in chromatogram II.

Solution