L-Histidine . hydrochloride . monohydrateProduct SpecificationFormula: C6H9N3O2 . HCl . H2O MW: 155.2 . 36.5 . 18.0 CAS: 5934-29-2; 7048-02-4 RTECS: MS3119000 Purity: ≥99% Appearance: White solid. Solubility: Soluble in water. Long Term Storage: Ambient