Specification Product Name BIEBRICH SCARLET (W.S.) Synonyms Acid Red 66; Croceine scarlet; Ponceau BS C.I. NO. 26905 CAS NO. 4196-99-0 Molecular Formula C22H14N4Na2O7S2 Formula Weight 556.49 Appearance Red to dark brown powder Structure     Tests    Limits Assay - 98% minimum Solubility (0.1% dist. H2O) - Clear red solution Absorption Max.(in water) at max. - 506 nm - 510 nm Absorptivity (A1%,1cm, in water, At max.) on dried substance 530 - 740 Loss On Drying(1100C) 1 hr 15% Max         REVISED: 1-1-2012