2-[[5-[3-[3-[[bis(carboxymethyl)amino]methyl]-4-hydroxy-5-methylphenyl]-1,1-dioxo-2,1λ⁶-benzoxathiol-3-yl]-2-hydroxy-3-methylphenyl]methyl-(carboxymethyl)amino]acetic acid, Xylenol Orange, 3,3'-Bis[N,N-bis(carboxymethyl)aminomethyl]-o-cresolsulfonphthalein Disodium Salt,