Strong Ammonia Solution
NH3 17.03

Ammonia.
Ammonia [7664-41-7].
»Strong Ammonia Solution is a solution of NH3,containing not less than 27.0percent and not more than 31.0percent (w/w)of NH3.On exposure to air it loses ammonia rapidly.
Caution—Use care in handling Strong Ammonia Solution because of the caustic nature of the Solution and the irritating properties of its vapor.Cool the container well before opening,and cover the closure with a cloth or similar material while opening.Do not taste Strong Ammonia Solution,and avoid inhalation of its vapor.
Packaging and storage— Preserve in tight containers,at a temperature not above 25.
Identification— Hold a glass rod moistened with hydrochloric acid near the surface of the Solution:dense,white fumes are produced.
Heavy metals,Method Iá231ñ— Evaporate 1.7mLon a steam bath to dryness,add to the residue 1mLof 3Nhydrochloric acid,and evaporate to dryness.Dissolve the residue in 2mLof 1Nacetic acid,and dilute with water to 25mL:the limit is 0.0013%.
Limit of nonvolatile residue— Evaporate a 10-mLportion in a tared platinum or porcelain dish to dryness,and dry at 105for 1hour:not more than 5mg of residue remains (0.05%).
Readily oxidizable substances— To a mixture of 4.0mLof Solution and 6mLof water add a slight excess of 2Nsulfuric acid and 0.10mLof 0.1Npotassium permanganate:the pink color does not completely disappear within 10minutes.
Assay— Transfer quickly a portion of Solution to a stoppered,thick-walled container (a pressure bottle is suitable)to obtain a column height of about 20cm,insert the stopper,and cool the container and contents to 10or lower.Weigh accurately a glass-stoppered,125-mLconical flask containing 35.0mLof 1Nsulfuric acid VS.Insert a graduated 10-mLmeasuring pipet into the cooled Solution,allow the liquid to rise in the pipet without vacuum,remove the pipet,wipe off adhering liquid,and discard the first mLof the Solution permitted to run from the pipet.Hold the pipet just above the surface of the 1Nsulfuric acid VSin the conical flask,and transfer about 2mLof the Solution into the flask.Insert the stopper,mix,and again weigh to obtain the weight of the specimen.Titrate the excess acid with 1Nsodium hydroxide VS,using methyl red TSas the indicator.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 2955
Phone Number:1-301-816-8262