Ammonium monovanadate

Ammonium metavanadate is the inorganic compound with the formula NH₄VO₃. It is a white solid, although samples are often yellow owing to impurities of V₂O₅. It is an important intermediate in the purification of vanadium.

Vanadium is often purified from aqueous extracts of slags and ore by selective precipitation of ammonium metavanadate. The material is then roasted to give vanadium pentoxide:

2 NH₄VO₃ → V₂O₅ + 2 NH₃ + H₂O

Other

Vanadates can behave as structural mimics of phosphates, and in this way they exhibit biological activity.

Ammonium metavanadate is used to prepare Mandelin reagent, a qualitative test for alkaloids.