Identification—
A:
Transfer a portion of the contents of Capsules, equivalent to about 2 g of ipodate sodium, to a 250-mL separator, add 100 mL of water and 50 mL of solvent hexane, and shake. Transfer the aqueous layer to a beaker, add 5 mL of 3 N hydrochloric acid, and mix. Filter (retain the filtrate), and wash the precipitate with several portions of water. Dry the precipitate in vacuum at 60
for 4 hours. A 1 in 100,000 solution of the residue so obtained, in a 1 in 100 mixture of 2 N hydrochloric acid in methanol, exhibits an UV absorbance maximum at 242 ± 2 nm.
C:
The filtrate obtained in
Identification test
A responds to the flame test for
Sodium 
191
.
Assay—
Place a number of Capsules, equivalent to about 5 g of ipodate sodium, in a 400-mL beaker, add 200 mL of 1 N sodium hydroxide and 50 mL of solvent hexane, and stir by mechanical means until the capsules have completely disintegrated. Transfer the mixture to a 500-mL separator, wash the beaker with a total of 25 mL of 1 N sodium hydroxide in divided portions, and add the washings to the separator. Allow the layers to separate, and transfer the aqueous layer to a 500-mL volumetric flask. Wash the solvent hexane layer with two 50-mL portions of 1 N sodium hydroxide, add the washings to the volumetric flask, dilute with 1 N sodium hydroxide to volume, and mix. Pipet 25 mL of the solution, which may be milky in appearance, into a 250-mL conical flask, add 500 mg of powdered zinc, and proceed as directed in the
Assay under
Ipodate Sodium, beginning with “and reflux the mixture for 60 minutes.”
