disodium p-[4,5-dihydro-5-imino-4-[[2-methoxy-5-[[2-(sulphonatooxy)ethyl]sulphonyl]phenyl]azo]-3-methyl-1H-pyrazol-1-yl]benzenesulphonate

4-[[4,5-Dihydro-5-imino-4-[[2-methoxy-5-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]azo]-3-methyl-1H-pyrazol]-1-yl]benzenesulfonic acid disodium salt