Ponceau colorants

Description

Scarlet red synthetic dyes first made in 1878 by a secret process developed by Brooke, Simpson, and Spiller. Ponceau colorants were used to dye wool and silk without a mordant. These water-soluble azo dyes were formerly used for coloring maraschino cherries prior to being removed from the FDA approved list for food in 1976.

• Ponceau 2R: Acid Red 26; CI 16150; Xylidine ponceau; Ponceau G; a red azo dye used in histology for staining; water soluble; usually a disodium salt
• Ponceau 3R: discontinued
• Ponceau 4R: Acid Red 18; CI 16255; Pigment Red 274; a crimson azo dye often used as a food coloring (not allowed in US, Canada, or Japan; Stable to light heat and acid
• Ponceau 6R: Acid Red 44; CI 16250; Crystal Ponceau 6R; a red azo dye used for food coloring and histology staining; soluble in water; usually a disodium salt
• Ponceau S: Acid Red 112; CI 27195; a sodium salt of a disazo dye used for histological staining of proteins
• Ponceau SX: Scarlet GN; once used as a food dye (E number E125)

Synonyms and Related Terms

ponceaux; Ponceau 2R; Ponceau SX; Ponceau 4R; Ponceau 6R

Physical and Chemical Properties

• Soluble in water.
• Slightly soluble in alcohols.
• Insoluble in oils.
• High heat resistance and good lightfastness.

Resources and Citations

• Wikipedia: Ponceau
• CHSOS: Spectra (Reflectance, XRF, Raman, FTIR) for PR 274 Ponceau 4R