Specification Product Name PONCEAU S Synonyms 3-Hydroxy-4-[2-sulfo-4-(4-sulfophenylazo)phenylazo]-2,7- naphthalenedisulfonic acid, tetrasodium salt CAS NO. 6226-79-5 C. I. No. 27195 Molecular Formula C22H12N4Na4O13S Formula Weight 760.56 Appearance Brownish Red Powder Structure     Tests    Limits Solubility 0.1% (dist. Water) - Clear Red Solution Absorptivity 1%/1cm, at λ max.520.0nm - >460 Dye Content (Spectrophotometry) - >75% Loss on Drying at 110°C (1hr) - <10%         REVISED: 1-1-2012