RP12- Thin-Layer Chromatography (TLC)

Question 1

After hydrolysing a protein into its constituent amino acids, the student analyses the resulting mixture by TLC.
When the solvent has risen up the TLC plate, the student removes the plate from the beaker and sprays it with a developing agent.
Name a suitable developing agent.
State why it is needed. (2)

Answer 1

Ninhydrin
∵ a.a. are colourless

Question 2

Explain why wearing plastic gloves when holding a TLC plate from analysing a mixture of amino acids is essential. (1)

Answer 2

prevent contamination from hand to plate

Question 3

Suggest a suitable reagent for the hydrolysis of a protein. (1)

Answer 3

conc. HCl

Question 4

Suggest why it was necessary to use two different solvents when separating amino acids in TLC. (1)

Answer 4

some a.a. x dissolve/ separate in first solvent