The reagent is prepared by decolorizing an aqueous p–rosaniline hydrochloride dye solution by the addition of sodium sulfite or by passing sulfur dioxide gas.
This dye is used to detect the presence of the aldehyde functional group in any compound.
Schiff's Test
In Schiff's test, the aldehyde containing group is exposed to some drops of the Schiff's reagent, and magenta or purple color development indicates the presence of the aldehyde functional group.
