title: Isolation, characterization and determination of trace organic impurities in FD&C red no. 40.
abstract: The unsulfonated aromatic amine 4-nitro-p-cresidine (2-methoxy-5-methyl-4-nitrobenzenamine) was identified as an impurity in the regulated color additive FD&C Red. No. 40. The compound was isolated from the water-soluble color by extraction with chloroform, followed by transfer of the free amines to acid solution and subsequent separation by reversed-phase high-performance liquid chromatography. The 4-nitro-p-cresidine was collected and then identified by gas chromatography-mass spectrometry. The levels of 4-nitro-p-cresidine as well as p-cresidine and aniline were determined in commercial batches of FD&C Red. No. 40.
authors.affiliation: Division of Colors and Cosmetics, Food and Drug Administration, Washington, DC 20204.
authors.forename: N
authors.initials: N
authors.lastname: Richfield-Fratz
authors.forename: W M
authors.initials: WM
authors.lastname: Baczynskyj
authors.forename: G C
authors.initials: GC
authors.lastname: Miller
authors.forename: J E
authors.initials: JE
authors.lastname: Bailey
mesh_terms: D000814:Aniline Compounds / Q000032:analysis*; D001391:Azo Compounds / Q000032:analysis*; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D004340:Drug Contamination / Q000032:analysis; D005505:Food Coloring Agents / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D009574:Nitro Compounds / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000814:Aniline Compounds; D001391:Azo Compounds; D005505:Food Coloring Agents; D009574:Nitro Compounds; C005915:Allura Red AC Dye; C060569:2-methoxy-5-methyl-4-nitroaniline