Chromatography — practice question

E150a and E155 are both brown food colourings. Devise an investigation to determine whether the brown food colouring in a soft drink is E150a or E155. Both food colourings dissolve in water. You are given solutions of E150a, E155 and the brown food colouring from the soft drink. You also have access to the apparatus usually available in a chemistry laboratory. You should include a labelled diagram with your plan and add the key practical details.