Aniline acetate test

The aniline acetate test is a chemical test for the presence of certain carbohydrates, in which they are converted to furfural with hydrochloric acid, which reacts with aniline acetate to produce a bright pink color.

A dry sample is dissolved in a small volume of hydrochloric acid and briefly heated.

A piece of paper, previously impregnated with aniline acetate, is exposed to the vapor from the sample solution.

Hydrochloric acid dehydrates pentoses (sugars containing five carbon atoms) to produce furfural.

Hexoses, which are sugars which contain six carbons, are not dehydrated to furfural, and so they do not produce a pink color.