Diluted Acetic Acid
»Diluted Acetic Acid is a solution containing,in each 100mL,not less than 5.7g and not more than 6.3g of acetic acid (C2H4O2).Prepare Diluted Acetic Acid as follows (see Pharmaceutical CompoundingNonsterile Preparations á795ñ):
Mix the ingredients.
Packaging and storage Preserve in tight containers.
Identification It meets the requirements of the tests for Acetate á191ñ.
Heavy metals,Method Iá231ñ Evaporate 5mLin a porcelain dish on a steam bath to dryness.Warm the residue with 2mLof 1Nacetic acid,and dilute with water to 50mL.Dilute 20mLof this solution with water to 25mL:not more than 0.001%is found.
Readily oxidizable substances To 20mLin a glass-stoppered flask add 0.30mLof 0.10Npotassium permanganate:the pink color is not changed to brown immediately,and the liquid does not become entirely brown or free from a pink tint in less than 30seconds.
Limit of nonvolatile residue Evaporate 20mLin a tared porcelain dish on a steam bath,and dry it at 105for 1hour:the weight of the residue does not exceed 1.0mg.Not more than 0.005%is found.
Limit of chloride Add 5drops of silver nitrate TSto 10mLof a solution (6in 10):no opalescence is found.
Limit of sulfate Add 5drops of barium chloride TSto 10mLof a solution (6in 10):no turbidity is produced.
Assay Transfer 25.0mLof Diluted Acetic Acid to a flask,and add 15mLof carbon dioxidefree water.Add phenolphthalein TS,and titrate with 1Nsodium hydroxide VS.Each mLof 1Nsodium hydroxide is equivalent to 60.05mg of C2H4O2.
Auxiliary Information Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist
Expert Committee:(PA6)Pharmaceutical Analysis 6
USP28NF23Page 2949Pharmacopeial Forum:Volume No.27(4)Page 2788