2-Naphthalenesulfonic acid, 6-amino-3-((2-((ethylphenylamino)sulfonyl)phenyl)azo)-4-hydroxy-, monosodium salt 2-Naphthalenesulfonic acid, 6-amino-3-((2-((ethylphenylamino)sulfonyl)phenyl)azo)-4-hydroxy-, sodium salt 74398-74-6