NH4Cl 53.49

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

Packaging and storage— Preserve in tight containers.

Identification— A solution (1 in 10) responds to the tests for Ammonium 191 and for Chloride 191.

pH 791: between 4.6 and 6.0, in a solution (1 in 20).

Loss on drying 731— Dry it over silica gel for 4 hours: it loses not more than 0.5% of its weight.

Residue on ignition 281— Add 1 mL of sulfuric acid to about 2 g, 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 10 mL of a solution (1 in 10) with hydrochloric acid, and add a few drops of ferric chloride TS: no orange-red color is produced.

Heavy metals, Method I 231: 0.001%.

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

Topic/Question	Contact	Expert Committee
Monograph	Elena Gonikberg, Ph.D. Senior Scientist 1-301-816-8251	(MDGRE05) Monograph Development-Gastrointestinal Renal and Endocrine

USP32–NF27 Page 1533