NaI 149.89

Sodium iodide.
Sodium iodide [7681-82-5].

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.

Water, Method I 921: not more than 2.0%.

Iodate— It meets the requirements of the test for Iodate under Potassium Iodide, 100 mg of Sodium Iodide being used in the control.

Thiosulfate and barium— It meets the requirements of the test for Thiosulfate and barium under Potassium Iodide.

Potassium— A solution of 1.0 g in 2 mL of water yields no precipitate with 1.0 mL of sodium bitartrate TS.

Heavy metals 231— Dissolve 2.0 g in 25 mL of water: the limit is 0.001%.

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.

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.

Topic/Question	Contact	Expert Committee
Monograph	Daniel K. Bempong, Ph.D. Senior Scientist 1-301-816-8143	(MDPS05) Monograph Development-Pulmonary and Steroids

USP32–NF27 Page 3577

SODIUM IODIDE

Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.