7-Benzothiazolesulfonic acid, 2-[4-[2-[1-[[(2-methoxy-5-sulfophenyl)amino]carbonyl]-2-oxopropyl]diazenyl]phenyl]-6-methyl-, compd. with α,α',α''-(nitrilotri-2,1-ethanediyl)tris[ω-hydroxypoly(oxy-1,2-ethanediyl)] (1:2)