1H-Pyrazole-3-carboxylic acid, 4,5-dihydro-5-oxo-4-((3-phosphonophenyl)azo)-1-(4-sulfophenyl)-, monosodium salt 4,5-Dihydro-5-oxo-4-((3-phosphonophenyl)azo)-1-(4-sulfophenyl)-1H-pyrazole-3-carboxylic acid, monosodium salt 68133-29-9 EINECS 268-673-5 Sodium trihydrogen 4,5-dihydro-5-oxo-4-((3-phosphonatophenyl)azo)-1-(4-sulphonatophenyl)-1H-pyrazole-3-carboxylate