Silicotungstic acid

Silicotungstic acid (CAS 12027-38-2, EC 234-719-8), also referenced as JM 1493 and α-H4SiW12O40, is a heteropolyacid composed of a silicon-centred tungsten-oxygen cluster. It carries no assigned E-code and belongs to the inorganic acids category. The compound is commercially handled as a crystalline solid hydrate.

In pharmaceutical manufacturing, silicotungstic acid functions as a strong Brønsted acid catalyst, driving condensation and esterification reactions under mild conditions. It is also applied in alkaloid precipitation assays, where it forms insoluble complexes with nitrogen-containing compounds to confirm identity or quantify active substances. Its buffering capacity supports pH control in select synthesis steps.

The material is supplied for industrial and research-grade applications and falls under REACH registration requirements for EU procurement. Buyers should confirm lot-specific documentation including CoA and SDS prior to order. Packaging formats vary by supplier; consult your account contact for available quantities.