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C5H5N3O 123.11

Pyrazinecarboxamide [98-96-4].
» Pyrazinamide contains not less than 99.0 percent and not more than 101.0 percent of C5H5N3O, calculated on the anhydrous basis.
Packaging and storage— Preserve in well-closed containers.
Solution: 10 µg per mL.
Medium: water.
Absorptivities at 268 nm, calculated on the dried basis, do not differ by more than 3.0%.
C: Boil 20 mg with 5 mL of 5 N sodium hydroxide: the odor of ammonia is perceptible.
Melting range 741: between 188 and 191.
Water, Method I 921: not more than 0.5%.
Residue on ignition 281: not more than 0.1%.
Assay— Place about 300 mg of Pyrazinamide, accurately weighed, in a 500-mL Kjeldahl flask, dissolve in 100 mL of water, and add 75 mL of 5 N sodium hydroxide. Connect the flask by means of a distillation trap to a well-cooled condenser, the delivery tube of which dips into 20 mL of boric acid solution (1 in 25) contained in a suitable receiver. Boil gently for 20 minutes, avoiding insofar as possible distilling any of the liquid, then boil vigorously to complete the distillation of the ammonia. Cool the liquid in the receiver if necessary, add methyl purple TS, and titrate with 0.1 N hydrochloric acid VS. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N hydrochloric acid is equivalent to 12.31 mg of C5H5N3O.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Behnam Davani, Ph.D., M.B.A.
Senior Scientist
(MDAA05) Monograph Development-Antivirals and Antimicrobials
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 3447
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.