Verification of aldehydes with Schiff's reagent

Chemicals needed

distilled water

Fuchsin sulphuric acid(Schiff's reagent)  GSGESUND.gif (476 Byte) Xi    R 36/37/38    S 26-36

propanal GSLEICHT.gif (932 Byte) F GSGESUND.gif (476 Byte) Xi   R 11-36/37/38     S (2)-9-16-29

One can also use other aliphatic and aromatic aldehydes, these often do not dissolve in water, simply emulsify through shaking. In order to convince onself of the specificity of the reagent one could also test in parallel a ketone such as acetone.

Equipment needed

Test procedure


The diluted solution can be discharged into the drainage. If one uses environmentally dangerous or toxic aldehydes, then properly dispose of as hazardous waste.


Schiff's reagent forms with aldehydes a colored bisulfite adduct. This verification is very specific and very sensitive.


DSCN0199.JPG (193216 Byte)

Propanal solution after the addition of Schiff's reagent


Of own device, similiar to that of many organic lab exercises.