sodium quinizarin-2-sulphonate, 9,10-Dihydro-1,4-dihydroxy-9,10-dioxo-2-anthracenesulfonic acid sodium salt, sodium 9,10-dihydro-1,4-dihydroxy-9,10-dioxoanthracene-2-sulphonate, 1,4-Dihydroxy-9,10-dioxoanthracene-2-sulfonic acid sodium salt, sodium 1,4-dihydroxy-9,10-anthraquinone-2-sulphonate,