title: Preparative separation of 1,3,6-pyrenetrisulfonic acid trisodium salt from the color additive D&C Green No. 8 (pyranine) by pH-zone-refining counter-current chromatography.
abstract: In developing analytical methods for batch certification of the color additive D&C Green No. 8 (G8), the U.S. Food and Drug Administration needed the trisodium salt of 1,3,6-pyrenetrisulfonic acid (P3S) for use as a reference material. Since P3S was not commercially available, preparative quantities of it were separated from portions of a sample of G8 that contained ∼3.5% P3S. The separations were performed by pH-zone-refining counter-current chromatography using dodecylamine (DA) as the hydrophobic counterion. The added DA enabled partitioning of the polysulfonated components into the organic stationary phase of the two-phase solvent system used, 1-butanol-water (1:1). Thus, a typical separation that involved 20.3g of G8, using sulfuric acid as the retainer acid and 20% DA in the stationary phase and 0.1M sodium hydroxide as the mobile phase, resulted in ∼0.58 g of P3S of greater than 99% purity. The identification and characterization of the separated P3S were performed by elemental analyses, proton nuclear magnetic resonance, high-resolution mass spectrometry, ultra-violet spectra, and high-performance liquid chromatography.
authors: Office of Cosmetics and Colors, Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration, HFS-106, 5100 Paint Branch Parkway, College Park, MD 20740, USA. adrian.weisz@fda.hhs.gov
authors: Adrian
authors: A
authors: Weisz
authors: Eugene P
authors: EP
authors: Mazzola
authors: Yoichiro
authors: Y
authors: Ito
mesh_terms: D000588:Amines / Q000737:chemistry; D001190:Arylsulfonates / Q000737:chemistry* / Q000592:standards; D002851:Chromatography, High Pressure Liquid; D003377:Countercurrent Distribution / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry; D019906:Nuclear Magnetic Resonance, Biomolecular; D011721:Pyrenes / Q000737:chemistry / Q000302:isolation & purification*; D012015:Reference Standards; D013056:Spectrophotometry, Ultraviolet; D013451:Sulfonic Acids / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: C569134:1,3,6-pyrenetrisulfonic acid trisodium salt; D000588:Amines; D001190:Arylsulfonates; D011721:Pyrenes; D013451:Sulfonic Acids; C005047:pyranine; C003935:dodecylamine