Synonyms: 2-Anthracenesulfonicacid, 9,10-dihydro-1,4-dihydroxy-9,10-dioxo-, monosodium salt (8CI,9CI);2-Anthraquinonesulfonic acid, 1,4-dihydroxy-, sodium salt (6CI);1,4-Dihydroxyanthraquinone-2-sulfonic acid sodium salt; C.I. Pigment Violet 5;Sodium quinizarin-2-sulfonate