title: Preparative separation of components of the color additive D&C Red No. 28 (phloxine B) by pH-zone-refining counter-current chromatography.
abstract: A pH-zone-refining counter-current chromatographic method was developed for the preparative (multigram) separation and purification of components of the commercial color additive D&C Red No. 28 (phloxine B). The chromatography of 3 and 6 g of color additive yielded 1.07 and 4.06 g, respectively, of pure 2',4',5',7'-tetrabromo-4,5,6,7-tetrachlorofluorescein, the principal component of D&C Red No. 28. The importance of the quantity of retainer acid (trifluoroacetic acid) relative to the amount of salt in the color additive is discussed.
authors.affiliation: Office of Cosmetics and Colors, US Food and Drug Administration, Washington, DC 20204.
authors.forename: A
authors.initials: A
authors.lastname: Weisz
authors.forename: D
authors.initials: D
authors.lastname: Andrzejewski
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods*; D010697:Eosine I Bluish / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry
chemical_list: D010697:Eosine I Bluish