Hydrochloric Acid
HCl 36.46

Hydrochloric acid.
Hydrochloric acid [7647-01-0].
»Hydrochloric Acid contains not less than 36.5percent and not more than 38.0percent,by weight,of HCl.
Packaging and storage— Preserve in tight containers.
Identification— It responds to the tests for Chloride á191ñ.
Residue on ignition á281ñ— To 20mLadd 2drops of sulfuric acid,evaporate to dryness,and ignite:not more than 2mg of residue remains (about 0.008%).
Bromide or iodide,Free bromine or chlorine,Sulfate,and Sulfite— Dilute it with 2volumes of water,to perform the following tests.
Bromide or iodide— Add 1mLof chloroform to 10mLof the dilution,and cautiously add,dropwise,with constant agitation,chlorine TSthat has been diluted with an equal volume of water:the chloroform remains free from even a transient yellow,orange,or violet color.
Free bromine or chlorine— Add 1mLof potassium iodide TSand 1mLof chloroform to 10mLof the dilution,and agitate the mixture:the chloroform remains free from any violet coloration for at least 1minute.
Sulfate— To a mixture of 3mLof the dilution and 5mLof water add 5drops of barium chloride TS:neither turbidity nor precipitate appears within 1hour.
Sulfite— On the completion of the test for Sulfate,the addition to the liquid of 2drops of 0.1Niodine produces neither turbidity nor decolorization of the iodine.
Heavy metals á231ñ— Evaporate 3.4mL(4g)on a steam bath to dryness,add 2mLof 1Nacetic acid to the residue,then dilute with water to 25mL:the limit is 5ppm.
Assay— Place about 3mLof Hydrochloric Acid in a glass-stoppered flask,previously tared while containing about 20mLof water,and weigh again to obtain the weight of the substance under assay.Dilute with about 25mLof water,add methyl red TS,and titrate with 1Nsodium hydroxide VS.Each mLof 1Nsodium hydroxide is equivalent to 36.46mg of HCl.
Auxiliary Information— Staff Liaison:Karen A Russo,Ph.D.,Scientist
Expert Committee:(EMC)Excipients:Monograph Content
USP28–NF23Page 3016
Phone Number:1-301-816-8379