Chemical Name P Amino Benzene Sulfonic Acid CAS No. 121 57 3 Molecular Weight 173.2 Molecular Formula C6H7NO3S Physical Appearance Grey Powder Form Fine (Dry) Powder Assay 98% min. Insolubles 0.30% max. Aniline By HPLC 5000 ppm Ash Content 0.5% max. Chromatography On 100% Basis