Bi5O(OH)9(NO3)4 1461.99

Bismuth hydroxide nitrate oxide Bi5O(OH)9(NO3)4.
Bismuth hydroxide nitrate oxide Bi5O(OH)9(NO3)4 [1304-85-4].

Packaging and storage— Preserve in well-closed containers.

Identification— It responds to the tests for Bismuth á191ñand for Nitrate á191ñ.

Loss on drying á731ñ— Dry it at 105for 2hours:it loses not more than 3.0%of its weight.

Carbonate— Add 3g to 3mLof warm nitric acid:no effervescence occurs.Pour the solution into 100mLof water:a white precipitate forms.Filter,evaporate the filtrate on a steam bath to 30mL,again filter the liquid,divide the latter filtrate into portions of 5mLeach,and use these several portions in the tests for Chloride,Sulfate,Copper,Lead,and Silver.

Chloride á221ñ— A10-mLportion of the test liquid retained in the test for Carbonateshows no more chloride than corresponds to 0.50mLof 0.020Nhydrochloric acid (0.035%).

Sulfate á221ñ— To a 5-mLportion of the test liquid retained in the test for Carbonateadd 5drops of barium nitrate TS:no turbidity is produced immediately.

Limit of ammonium salts— Boil about 100mg with 5mLof 1Nsodium hydroxide:the vapor does not turn moistened red litmus paper blue.

Arsenic,Method Iá211ñ— Mix 375mg with 5mLof water,cautiously add 2mLof sulfuric acid,and heat the mixture until fumes of sulfur trioxide are copiously evolved.Cool,cautiously add 10mLof water,and again evaporate to strong fuming,repeating,if necessary,to remove any trace of nitric acid.The limit is 8ppm.

Copper— To a 5-mLportion of the test liquid retained in the test for Carbonateadd a slight excess of 6Nammonium hydroxide:the liquid does not exhibit a bluish color.

Lead— Mix a 5-mLportion of the test liquid retained in the test for Carbonatewith an equal volume of 2Nsulfuric acid:the liquid does not become cloudy.

Silver— To a 5-mLportion of the test liquid retained in the test for Carbonateadd hydrochloric acid,dropwise:no precipitate is formed that is insoluble in a slight excess of hydrochloric acid,but that is soluble in 6Nammonium hydroxide.

Limit of alkalies and alkaline earths— Boil 1.0g with 20mLof a mixture of equal volumes of 6Nacetic acid and water,cool,and filter.Add 2mLof 3Nhydrochloric acid,precipitate the bismuth by the addition of hydrogen sulfide,boil the mixture,and filter it.Add 5drops of sulfuric acid to the filtrate,evaporate to dryness,and ignite to constant weight:the weight of the residue does not exceed 5mg (0.5%).

Assay— Transfer about 400mg of Bismuth Subnitrate,accurately weighed,to a 250-mLbeaker.Add 5mLof water,then add 2mLof nitric acid,and warm,if necessary,to effect solution.Dilute with water to 100mL,add 0.3mLof xylenol orange TS,and titrate with 0.05Medetate disodium VSto a yellow endpoint.Each mLof 0.05Medetate disodium is equivalent to 11.65mg of Bi2O3.

Expert Committee:(PA4)Pharmaceutical Analysis 4

USP28–NF23Page 266

Phone Number:1-301-816-8251