Ammoniated Mercury
Hg(NH2)Cl
252.07
Mercury amide chloride.
Mercury amide chloride [10124-48-8].
»Ammoniated Mercury contains not less than 98.0percent and not more than 100.5percent of Hg(NH2)Cl.
Packaging and storage—
Preserve in well-closed,light-resistant containers.
Identification—
A:
A0.1-g portion is soluble,with the evolution of ammonia,in a cold solution of 1g of sodium thiosulfate in 2mLof water.When this solution is heated gently,a rust-colored mixture is formed,from which a red precipitate is obtained on centrifugation.If the solution is strongly heated,a black mixture forms.
B:
When heated with 1Nsodium hydroxide,it becomes yellow,and ammonia is evolved.
C:
Asolution in warm acetic acid yields with potassium iodide TSa red precipitate,which is soluble in an excess of the reagent.The solution yields a white precipitate with silver nitrate TS.
Residue on ignition á281ñ:
not more than 0.2%.
Mercurous compounds—
Dissolve 2.5g in 25mLof warm hydrochloric acid,filter through a tared filtering crucible,wash with water,and dry at 60
to constant weight:the weight of the residue does not exceed 5mg (0.2%).
to constant weight:the weight of the residue does not exceed 5mg (0.2%).
Assay—
Mix about 0.25g of Ammoniated Mercury,accurately weighed,with about 10mLof water.Add 3g of potassium iodide,mix occasionally until dissolved,and add about 40mLof water.Add methyl red TS,and titrate with 0.1Nhydrochloric acid VS.Perform a blank determination,and make any necessary correction.Each mLof 0.1Nhydrochloric acid is equivalent to 12.60mg of Hg(NH2)Cl.
Auxiliary Information—
Staff Liaison:Behnam Davani,Ph.D.,MBA,Senior Scientist
Expert Committee:(PA7)Pharmaceutical Analysis 7
USP28–NF23Page 1217
Phone Number:1-301-816-8394