Phenylmercuric Nitrate
(fen'' il mer kure' ik nye' trate).
Mercury, (nitrato-O)phenyl-.
Nitratophenylmercury
[55-68-5].» Phenylmercuric Nitrate is a mixture of phenylmercuric nitrate and phenylmercuric hydroxide containing not less than 87.0 percent and not more than 87.9 percent of phenylmercuric ion (C6H5Hg+), and not less than 62.75 percent and not more than 63.50 percent of mercury (Hg).
Packaging and storage—
Preserve in tight, light-resistant containers.
Identification—
A:
Add 3 mL of sulfuric acid to 0.1 g of it: the mixture becomes yellow, and the characteristic odor of nitrobenzene is evolved.
B:
To 5 mL of a saturated solution of it add 1 mL of 3 N hydrochloric acid: a white precipitate is formed.
C:
To 5 mL of a saturated solution of it add 5 mL of ammonium sulfide TS: there is no reaction in the cold, but upon heating in a boiling water bath for 10 minutes a black precipitate is formed.
Residue on ignition 
281
:
not more than 0.1%.
281:
not more than 0.1%.
Mercury ions—
To 5 mL of a saturated solution add 5 mL of 1 N sodium hydroxide: no yellow precipitate is formed (mercuric ions) and the solution does not darken (mercurous ions).
Assay for phenylmercuric ions—
Transfer about 200 mg, accurately weighed, to a conical flask, and dissolve in 90 mL of water and 10 mL of nitric acid. Add 2 mL of ferric ammonium sulfate TS, and titrate with 0.05 N ammonium thiocyanate VS. Each mL of 0.05 N ammonium thiocyanate is equivalent to 13.88 mg of phenylmercuric ion (C6H5Hg+).
Assay for mercury—
Transfer about 400 mg of Phenylmercuric Nitrate, accurately weighed, to a 100-mL flask, add 15 mL of water, 5 mL of formic acid, and 1 g of zinc dust, and reflux for 30 minutes. Cool, filter, and wash the filter paper and the amalgam with water until the washings are no longer acid to litmus. Dissolve the amalgam in 40 mL of 8 N nitric acid. Heat on a steam bath for 3 minutes, then add 0.5 g of urea and enough potassium permanganate TS to produce a permanent pink color. Cool, decolorize the solution with hydrogen peroxide TS, add 1 mL of ferric ammonium sulfate TS, and titrate with 0.1 N ammonium thiocyanate VS. Each mL of 0.1 N ammonium thiocyanate is equivalent to 10.03 mg of Hg.
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Robert H. Lafaver, M.S.
Scientific Liaison 1-301-816-8335 |
(EXC2010) Monographs - Excipients |
USP35–NF30 Page 1890