A sample of orange juice is suspected to have been contaminated with a yellow dye. Which of the following methods can be used to detect the dye?

Chromatography separates the dyes and colouring matter in a mixture. A drop of the orange juice is placed on chromatography paper. A solvent then moves up the paper. Each dye travels at its own speed, because they differ in how well they dissolve and stick to the paper.

If a yellow dye is present, it shows as a separate coloured spot that can be compared with a known sample.

Decantation and filtration only separate solids from liquids. Distillation separates liquids by boiling point. None of them can pick out a small amount of dissolved dye.