NH4Cl 53.49

Ammonium chloride.
Ammonium chloride [12125-02-9].

Packaging and storage— Preserve in tight containers.

Identification— Asolution (1in 10)responds to the tests for Ammonium á191ñand for Chloride á191ñ.

pHá791ñ: between 4.6and 6.0,in a solution (1in 20).

Loss on drying á731ñ— Dry it over silica gel for 4hours:it loses not more than 0.5%of its weight.

Residue on ignition á281ñ— Add 1mLof sulfuric acid to about 2g,accurately weighed,and heat the mixture gently until volatilization is complete:the residue is white,and when ignited,not more than 0.1%of nonvolatile substance remains.

Limit of thiocyanate— Acidify 10mLof a solution (1in 10)with hydrochloric acid,and add a few drops of ferric chloride TS:no orange-red color is produced.

Heavy metals,Method Iá231ñ: 0.001%.

Assay— Transfer about 100mg of Ammonium Chloride,accurately weighed,to a conical flask,add 10mLof water,and swirl to dissolve.Add 10mLof glacial acetic acid,75mLof methanol,and 0.5mLof eosin Y TS.Titrate,with shaking,with 0.1Nsilver nitrate VSto a pink endpoint.Each mLof 0.1Nsilver nitrate is equivalent to 5.349mg of NH4Cl.

Expert Committee:(PA4)Pharmaceutical Analysis 4

USP28–NF23Page 137

Phone Number:1-301-816-8251