Formula: C₅H₅N₅ CAS: 73-24-5 EC No.: 200-796-1 M (Molar Mass): 135.13 g/mol mp (Melting Point): >360°C (sublimes) Appearance: White to off-white crystalline powder

Assay (HPLC): ≥ 99.0%. Appearance: White to off-white crystalline powder. Identification (UV): λmax = 260 nm (in 0.1N HCl). Melting Point: >360°C (sublimes). Loss on Drying: ≤ 0.5% (at 105°C for 2 hours). Residue on Ignition: ≤ 0.1%. Heavy Metals (as Pb): ≤ 10 ppm. Related Substances (HPLC): Total impurities ≤ 0.5%. Hypoxanthine: ≤ 0.1%. Guanine: ≤ 0.1%. pH (saturated solution): 6.5-7.5. UV Ratio: A250/A260 = 0.78-0.83, A280/A260 = 0.38-0.42 (in 0.1N HCl).