Synonyms: Benzenesulfonicacid,2,2'-[(9,10-dihydro-4,8-dihydroxy-9,10-dioxo-1,5-anthracenediyl)diimino]bis[5-methyl-,disodium salt (9CI); m-Toluenesulfonic acid,6,6'-[(4,8-dihydroxy-1,5-anthraquinonylene)diimino]di-, disodium salt(7CI,8CI); C.I. 63340; Toluidine blue; Toluidine blue (anthraquinone dye)