Ammonium Carbonate

Carbonic acid,monoammonium salt,mixt.with ammonium carbamate.
Monoammonium carbonate mixture with ammonium carbamate [8000-73-5].
»Ammonium Carbonate consists of ammonium bicarbonate (NH4HCO3)and ammonium carbamate (NH2COONH4)in varying proportions.It yields not less than 30.0percent and not more than 34.0percent of NH3.
Packaging and storage— Preserve in tight,light-resistant containers,at a temperature not above 30.
Identification— When heated,it is volatilized without charring,and the vapor is alkaline to moistened litmus paper.Asolution (1in 20)effervesces with acids.
Residue on ignition á281ñ: not more than 0.1%.
Chloride á221ñ A2.0-g portion shows no more chloride than corresponds to 0.10mLof 0.020Nhydrochloric acid (0.0035%).
Sulfate á221ñ A2.0-g portion shows no more sulfate than corresponds to 0.10mLof 0.020Nsulfuric acid (0.005%).
Heavy metals,Method Iá231ñ Reduce to a coarse powder and volatilize 2g of it on a steam bath.Add to the residue 1mLof 3Nhydrochloric acid,and evaporate to dryness.Dissolve the residue in 2mLof 1Nacetic acid,and add water to make 25mL:the limit is 0.001%.
Assay— Place in a weighing bottle about 10mLof water,tare the bottle and its contents,add about 2g of Ammonium Carbonate,and weigh accurately.Transfer the contents of the bottle to a 250-mLflask,add 50.0mLof 1Nsulfuric acid VS,and,when solution has been effected,add methyl orange TS,and titrate the excess acid with 1Nsodium hydroxide VS.Perform a blank determination (see Residual Titrations underTitrimetry á541ñ).Each mLof 1Nsulfuric acid is equivalent to 17.03mg of NH3.
Auxiliary Information— Staff Liaison:Catherine Sheehan,B.Sc.,Scientist
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 2956
Phone Number:1-301-816-8262