1-Naphthalenesulfonic acid, 2-((2-hydroxy-3,6-disulfonic acid-1-naphthalenyl)azo), barium salt (3:2) 2,7-Naphthalenedisulfonic acid, 3-hydroxy-4-((1-sulfo-2-naphthalenyl)azo)-, barium salt (2:3) 70729-66-7