Aluminum Chloride
AlCl3·6H2O 241.43

Aluminum chloride,hexahydrate.
Aluminum chloride hexahydrate [7784-13-6].

Anhydrous 133.34 [7446-70-0].
»Aluminum Chloride contains not less than 95.0percent and not more than 102.0percent of AlCl3,calculated on the anhydrous basis.
Packaging and storage— Preserve in tight containers.
Identification— Asolution (1in 10)responds to the tests for Aluminum á191ñand for Chloride á191ñ.
Water,Method Iá921ñ: between 42.0%and 48.0%.
Sulfate— The addition of 0.2mLof barium chloride TSto 10mLof a solution (1in 100)produces no turbidity within 1minute.
Limit of alkalies and alkaline earths— To a boiling solution of 1.0g in 150mLof water add a few drops of methyl red TS,then add 6Nammonium hydroxide until the color of the solution just changes to a distinct yellow.Add hot water to restore the volume to 150mL,and filter while hot.Evaporate 75mLof the filtrate to dryness,and ignite to constant weight:the weight of the residue does not exceed 2.5mg (0.5%).
Heavy metals,Method Iá231ñ— Dissolve 1g in 1mLof 1Nacetic acid and sufficient water to make 25mL:the limit is 0.002%.
Iron á241ñ— Dissolve 1.0g in 45mLof water,and add 2mLof hydrochloric acid:the limit is 0.001%.
Assay—
Edetate disodium titrant— Prepare and standardize as directed in the Assayunder Ammonium Alum.
Procedure— Transfer to a 250-mLvolumetric flask about 5g of Aluminum Chloride,accurately weighed,dissolve in and dilute with water to volume,and mix.Transfer 10.0mLof the solution to a 250-mLbeaker,and add,in the order named and with continuous stirring,25.0mLof Edetate disodium titrant,and 20mLof acetic acid-ammonium acetate buffer TS,and boil gently for 5minutes.Cool,and add 50mLof alcohol and 2mLof dithizone TS.Titrate with 0.05Mzinc sulfate VSto a bright rose-pink color.Perform a blank determination,substituting 10mLof water for the assay preparation,and make any necessary correction.Each mLof 0.05MEdetate disodium titrantis equivalent to 6.667mg of AlCl3.
Auxiliary Information— Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist
Expert Committee:(PA6)Pharmaceutical Analysis 6
USP28–NF23Page 87
Phone Number:1-301-816-8389