disodium 3-[[3-methoxy-4-[[[2-methoxy-5-methyl-4-[(3-sulphonatophenyl)azo]anilino]carbamoyl]amino]phenyl]azo]benzenesulphonate;3-[[3-Methoxy-4-[[[[2-methoxy-5-methyl-4-[(3-sulfophenyl)azo]phenyl]amino]carbonyl]amino]phenyl]azo]benzenesulfonic acid disodium salt