CHROMOTRORE Chromotrope 2R, pure 2,7-Naphthalenedisulfonic acid, 4,5-dihydroxy-3-(phenylazo)-, disodium salt 2-(Phenylazo)chromotropic acid disodium salt, Acid Red29 C.I.Mordant Blue 80 Chromotrope N-2R Chromotrop 2 R, C.I. 16570, for complexometry Acid phloxin GR