1-(Bis(4-(diethylamino)phenyl)methyl)naphthalene-2,7-disulphonic acid 1-(Bis(p-diethylaminophenyl)methyl)-2,7-naphthalenedisulfonic acid 2,7-Naphthalenedisulfonic acid, 1-(bis(4-(diethylamino)phenyl)methyl)- 68345-20-0 EINECS 269-848-9