Packaging and storage—
Preserve in tight containers.
Identification—
A solution (1 in 20) responds to the tests for
Sodium 
191
and for
Iodide 191.
Alkalinity—
Dissolve 1.0 g in 10 mL of water, and add 0.15 mL of 0.10 N sulfuric acid: no red color is produced by the addition of 1 drop of phenolphthalein TS.
Iodate—
It meets the requirements of the test for
Iodate under
Potassium Iodide, 100 mg of Sodium Iodide being used in the control.
Potassium—
A solution of 1.0 g in 2 mL of water yields no precipitate with 1.0 mL of
sodium bitartrate TS.
Limit of nitrate, nitrite, and ammonia—
Add 5 mL of 1 N sodium hydroxide and about 200 mg of aluminum wire to a solution of 1.0 g of Sodium Iodide in 5 mL of water, contained in a test tube of about 40-mL capacity. Insert a pledget of purified cotton in the upper portion of the test tube, and place a piece of moistened red litmus paper over the mouth of the tube. Heat in a steam bath for 15 minutes: no blue coloration of the paper is discernible.
Organic volatile impurities, Method I 467:
meets the requirements.
Assay—
Weigh accurately about 500 mg of Sodium Iodide, and dissolve in about 10 mL of water. Add 35 mL of hydrochloric acid, and titrate with 0.05 M potassium iodate VS until the dark brown solution which is produced becomes pale brown. Add 1 mL of amaranth TS, and continue the titration slowly until the red color just changes to yellow. Each mL of 0.05 M potassium iodate is equivalent to 14.99 mg of NaI.
