2-((2-Hydroxy-1-naphthalenyl)azo)-1,5-naphthalenedisulfonic acid, magnesium salt (1:1) 67939-69-9 EINECS 267-848-3 Hydrogen (2-((2-hydroxy-1-naphthyl)azo)naphthalene-1,5-disulphonato(3-))magnesate(1-) Magnesate(1-), (2-((2-(hydroxy-kappaO)-1-naphthalenyl)azo-kappaN1)-1,5-naphthalenedisulfonato(3-)-kappaO)-, hydrogen