Phosphomolybdic acid (PMA) hydrate is primarily used in spectrophotometric determination of phosphate ions. PMA is a component in the 3-color histology stain called Masson’s trichrome; employed in the differentiation step, Phosphomolybdic acid is one of the solutions fixed tissues are immersed in prior to subsequent staining. Phosphomolybdic acid is also used as reagent for simple and rapid colorimetric determination of phenothiazine derivatives. PMA oxidizes the phenothiazine derivative to a cationic free radical, forming a coloured salt. A preliminary extraction is necessary if certain reductants (sulphite or ascorbic acid) are present as stabilizers, as they will reduce the reagent to phosphomolybdenum blue.A reagent used for spectrophotometric determination of phosphate ions.用于制备有机-无机杂化电活性材料，可用作电池中的阳离子插入电极。磷钼酸水合物可用于合成二硫化钼（MoS2）还原的石墨烯氧化物（RGO）复合材料，其可用作钠离子电池的电极。以过氧化氢作为氧化剂时，它也可以用作催化剂前体，用于催化柴油燃料中的二苯并噻吩氧化。有机-无机杂化材料分子电池的前体，用作阳离子插入电极。
