5549-75-7 Benzenesulfonic acid, 5,5'-(4,5,6,7-tetraiodo-3-oxo-1(3H)-isobenzofuranylidene)bis(2-hydroxy-,disodium salt Iodosulfophthalein Iodosulphalein Iodosulphthalein Phenolphthalein, 4,5,6,7-tetraiodo-3',3''-disulfo-, disodium salt (7CI,8CI) Sulfoiodophthalein