Phosphonazo III Item No.: P3 C.A.S. No.: 16017-11-1 Chemical Formula: C22H18N4O14P2S2 Chemical Name: Phosphonazo III; 4,5-Dihydroxy-3,6-bis[(o-phosphonophenyl)azo]-2,7-naphthalenedisulfonic acid Chemical Structure: Formula Weight: 688.5 Specifications: Physical Properties: dark purple liquid Storage: Store product container tightly sealed at room temperature.