72968-21-9 Chromium, 4-hydroxy-3-((2-hydroxy-1-naphthalenyl)azo)benzenesulfonamide N-(7-hydroxy-8-((2-hydroxy-5-nitrophenyl)azo)-1-naphthalenyl)acetamide 4-hydroxy-3-((5-hydroxynaphth(2,1-d)-1,3-oxathiol-4-yl)azo)benzenesulfonamide S,S-dioxide sodium complexes