Chromatogram analysis exercise

In this experiment, we use paper chromatography to separate and identify a mixture of three amino acids. Care needs to be taken as it is easy to contaminate the paper with amino acids from the sweat on the skin. We run the chromatogram with the mixture and with six known, individual amino acids. These are given their three letter codes at the top of the chromatography paper. As the amino acids are colourless, we have to develop the chromatogram so that it is possible to see the various spots once they have moved. We use ninhydrin for this purpose. On heating, this stains the amino acids various shades of blue and purple.

Look at the photograph of the developed chromatogram. Try to decide from the positions and colours of the various spots which three amino acids were present in the mixture. Make a calculation of the various R_f values to confirm your suspicions. Check your answer by clicking on this link.