Benzenesulfonic acid, 4-[4-[[2,5-dimethoxy-4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]-, sodium salt

4-[4-[[2,5-dimethoxy-4-[[2-(sulphooxy)ethyl]sulphonyl]phenyl]azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazol-1-yl]benzenesulphonic acid, sodium salt

4-[[4-[[2,5-Dimethoxy-4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]azo]-4,5-dihydro-3-methyl-5-oxo-1H-pyrazole]-1-yl]benzenesulfonic acid/sodium,(1:x) salt