Fluorescent brightening agent 1 (C.I. 40630)

disodium 4,4'-bis[(4,6-diamino-1,3,5-triazin-2-yl)amino]stilbene-2,2'-disulphonate

2,2'-(1,2-Ethenediyl)bis[5-[(4,6-diamino-1,3,5-triazin-2-yl)amino]benzenesulfonic acid]disodium salt