[Unco]

I am attempting to make ninhydrin TLC stain, but the recipes online all disagree with each other of what the ingredients and their ratios are. Does anyone know what a reliable recipe for ninhydrin stain is?

[pgk]

For spray purpose: 0.25% w/w ninhydrin solution in n-butanol.
For test tube purpose: 0.25% w/w aqueous ninhydrin solution.

[Babcock_Hall]

0.3% ninhydrin in 95% ethanol has work OK for us.

[pgk]

The higher the alcoholic solvent boiling point, the higher the temperatures during TLC development, can be achieved  and therefore, the better the staining is supposed to be. But of course, this depends on the desired working conditions. Besides and for similar reasons, the ninhydrin content may vary within 0.2 - 0.3% w/w.