Phenylmercuric Nitrate

Mercury,(nitrato-O)phenyl-.
Nitratophenylmercury [55-68-5].
»Phenylmercuric Nitrate is a mixture of phenylmercuric nitrate and phenylmercuric hydroxide containing not less than 87.0percent and not more than 87.9percent of phenylmercuric ion (C6H5Hg+),and not less than 62.75percent and not more than 63.50percent of mercury (Hg).
Packaging and storage— Preserve in tight,light-resistant containers.
Identification—
A: Add 3mLof sulfuric acid to 0.1g of it:the mixture becomes yellow,and the characteristic odor of nitrobenzene is evolved.
B: To 5mLof a saturated solution of it add 1mLof 3Nhydrochloric acid:a white precipitate is formed.
C: To 5mLof a saturated solution of it add 5mLof ammonium sulfide TS:there is no reaction in the cold,but upon heating in a boiling water bath for 10minutes a black precipitate is formed.
Residue on ignition á281ñ: not more than 0.1%.
Mercury ions— To 5mLof a saturated solution add 5mLof 1Nsodium hydroxide:no yellow precipitate is formed (mercuric ions)and the solution does not darken (mercurous ions).
Assay for phenylmercuric ions— Transfer about 200mg,accurately weighed,to a conical flask,and dissolve in 90mLof water and 10mLof nitric acid.Add 2mLof ferric ammonium sulfate TS,and titrate with 0.05Nammonium thiocyanate VS.Each mLof 0.05Nammonium thiocyanate is equivalent to 13.88mg of phenylmercuric ion (C6H5Hg+).
Assay for mercury— Transfer about 400mg of Phenylmercuric Nitrate,accurately weighed,to a 100-mLflask,add 15mLof water,5mLof formic acid,and 1g of zinc dust,and reflux for 30minutes.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 40mLof 8Nnitric acid.Heat on a steam bath for 3minutes,then add 0.5g of urea and enough potassium permanganate TSto produce a permanent pink color.Cool,decolorize the solution with hydrogen peroxide TS,add 1mLof ferric ammonium sulfate TS,and titrate with 0.1Nammonium thiocyanate VS.Each mLof 0.1Nammonium thiocyanate is equivalent to 10.03mg of Hg.
Auxiliary Information— Staff Liaison:Catherine Sheehan,B.Sc.,Scientist
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 3049
Phone Number:1-301-816-8262