- Synonyms: 4,5-Dihydroxy-2,7-naphthalenedisulfonic acid disodium salt dihydrater- C10H6Na2O8S2·2H2Or- M = 400,30 g/molr- CAS [5808-22-0]r- EINECS-No.: 204-972-9r- Solub. in water: (20 ºC): 170 g/lr- Tariff number: 2908 99 00 90r- Applications: analytical chemistry, manufacture of dyes, for determination of: silver, mercury, chlorates, nitrates, nitrites, chromium and titanium.rrSPECIFICATIONSrclarity of solution: passes testrsuitability for determination of formaldehyde: passes testrsuitability for determination of nitrates: passes testr