2-Naphthalenesulfonic acid, 7,7'-(carbonyldiimino)bis(4-hydroxy-3-((6-sulfo-2-naphthalenyl)azo)-, compd. with 2,2'-(methylimino)bis(ethanol) (1:4) 7,7'-(Carbonyldimino)bis(4-hydroxy-3-((6-sulfo-2-naphthalenyl)azo)-2-naphthalenesulfonic acid) tetra(methyldiethanolamine) salt 72869-93-3