4-[[5-[[4-Chloro-6-[(4-sulfophenyl)amino]-1,3,5-triazin-2-yl]amino]-2-sulfophenyl]azo]-4,5-dihydro-5-oxo-1-(4-sulfophenyl)-1H-pyrazole-3-carboxylic acid tetrasodium salt

tetrasodium 4-[[5-[[4-chloro-6-[(4-sulphonatophenyl)amino]-1,3,5-triazin-2-yl]amino]-2-sulphonatophenyl]azo]-4,5-dihydro-5-oxo-1-(4-sulphonatophenyl)-1H-pyrazole-3-carboxylate