sodium 3-[(8-amino-2-hydroxy-1-naphthyl)azo]-5-chloro-2-hydroxybenzenesulphonate;3-[2-(8-amino-2-oxonaphthalen-1-ylidene)hydrazinyl]-5-chloro-2-hydroxybenzenesulfonate;3-(8-Amino-2-hydroxy-1-naphthalenylazo)-5-chloro-2-hydroxybenzenesulfonic acid sodium salt