Toughened Silver Nitrate
» Toughened Silver Nitrate contains not less than 94.5 percent of AgNO3, the remainder consisting of silver chloride (AgCl).
Packaging and storage— Preserve in tight, light-resistant containers.
Identification—
A: A solution (1 in 50) responds to the tests for Silver 191.
B: Mix a solution (1 in 10) in a test tube with 1 drop of diphenylamine TS, then carefully superimpose it upon sulfuric acid: a deep blue color appears at the zone of contact.
Copper— A solution (1 in 10) shows no trace of blue coloration when treated with an excess of 6 N ammonium hydroxide.
Assay— Add about 700 mg of Toughened Silver Nitrate, accurately weighed, to 50 mL of water, and when the silver nitrate has dissolved, filter the solution. Thoroughly wash the filter and sediment with water, add 2 mL of nitric acid and 2 mL of ferric ammonium sulfate TS to the combined filtrate and washings, and titrate with 0.1 N ammonium thiocyanate VS. Each mL of 0.1 N ammonium thiocyanate is equivalent to 16.99 mg of AgNO3.
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
1-301-816-8394
(MDAA05) Monograph Development-Antivirals and Antimicrobials
USP32–NF27 Page 3554