E 1731 (OTTO) Europium nitrate, hexahydrate, 99.99% Cas 10031-53-5 - used in the preparation of pharmaceuticals, agrochemicals and other chemical products. E 1731 (OTTO) Europium nitrate, hexahydrate, 99.99% Cas 10031-53-5 - used as a catalyst and a component of specialized steels. It is also used in the synthesis of light emitting nanomaterials.