Al2(SO4)3·xH2O (anhydrous) 342.15
Sulfuric acid, aluminum salt (3:2), hydrate.
Aluminum sulfate (2:3) hydrate [17927-65-0].
Anhydrous 342.16 [10043-01-3].
» Aluminum Sulfate contains not less than 54.0 percent and not more than 59.0 percent of Al2(SO4)3. It contains a varying amount of water of crystallization.
Packaging and storage Preserve in well-closed containers.
Identification A solution (1 in 10) responds to the tests for Aluminum and for Sulfate 191.
pH 791: not less than 2.9, in a solution (1 in 20).
Water, Method I 921: not less than 41.0% and not more than 46.0%.
Heavy metals 231 Dissolve 1.0 g in 2 mL of 1 N acetic acid, and dilute with water to 25 mL. The limit is 20 µg per g.
Limit of alkalies and alkaline earths To a boiling solution of 1.0 g in 150 mL of water add a few drops of methyl red TS and then add 6 N ammonium hydroxide just until the color of the solution changes to a distinct yellow. Add hot water to restore the volume to 150 mL, and filter while hot. Evaporate 75 mL of the filtrate to dryness, and ignite to constant weight: not more than 2 mg of residue remains (0.4%).
Limit of ammonium salts Heat 1 g with 10 mL of 1 N sodium hydroxide on a steam bath for 1 minute: the odor of ammonia is not perceptible.
Iron To 20 mL of a solution (1 in 150) add 0.3 mL of potassium ferrocyanide TS: no blue color is produced immediately.
Procedure Transfer about 7.5 g of Aluminum Sulfate, accurately weighed, to a 250-mL volumetric flask, and dissolve in water. Dilute with water to volume, mix, and pipet 10 mL of the solution into a 250-mL beaker. Proceed as directed in the Assay for aluminum oxide under Aluminum Acetate Topical Solution, beginning with add, in the order named. Each mL of 0.05 M Edetate disodium titrant is equivalent to 8.554 mg of Al2(SO4)3.
Auxiliary Information Please check for your question in the FAQs before contacting USP.Chromatographic Column
USP32NF27 Page 1488
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.