tetrasodium 3,3'-[azoxybis[[3-(2-hydroxyethoxy)-4,1-phenylene]azo]]bis[4-hydroxy-5-[[(p-tolyl)sulphonyl]amino]naphthalene-2,7-disulphonate]

3,3'-[ONN-Azoxybis[[3-(2-hydroxyethoxy)-4,1-phenylene]azo]]bis[4-hydroxy-5-[[(4-methylphenyl)sulfonyl]amino]-2,7-naphthalenedisulfonic acid disodium] salt