4,4'-Bis((p-hydroxyphenyl)azo)-2,2'-stilbenedisulfonic acid, potassium sodium salt (1:1:1) 75673-23-3 91-34-9 Benzenesulfonic acid, 2,2'-(1,2-ethenediyl)bis(5-((4-hydroxyphenyl)azo)-, monopotassium monosodium salt