i. Thin-layer chromatography (TLC) :
If components are colourless but have the property of fluorescence then they can be visualized under UV light, or the plate can be kept in a chamber containing a few iodine crystals. The iodine vapours are adsorbed by the components and the spots appear brown. Also, spraying agent like ninhydrin can also be used (for amino acids).
ii. Paper Chromatography :
The spots of the separated colourless components may be observed either under ultra-violet light or by the use of an appropriate spraying agent.
