2,7-Naphthalenedisulfonic acid, 3-hydroxy-4-((2-methyl-4-((2-methylphenyl)azo)phenyl)azo)-, disodium salt 6226-80-8 8005-61-6 Disodium 3-hydroxy-4-((2-methyl-4-((o-tolyl)azo)phenyl)azo)naphthalene-2,7-disulphonate EINECS 228-320-8