Trioxovanadate

Ammonium metavanadate, NH4VO3, a yellow crystalline solid[1] which dissolves in water, is the most common laboratory vanadate reagent, along with potassium metavanadate, KVO3.

Potassium citrate is a potassium salt of citric acid with the molecular formula C6H5K3O7. It is a white, slightly hygroscopic crystalline powder. It is odorless with a saline taste.

Sodium metavanadate is a yellow solid which is soluble in water. Its use is limited due to its hygroscopic property. Its natural forms include mineral metamunirite (anhydrous) and a dihydrate, munirite.