Packaging and storage—
Preserve in tight containers, preferably at a temperature not exceeding 35
.
Identification—
A:
Dilute 1 drop with 10 mL of water, and add 1 mL of starch TS: a deep blue color is produced.
B:
Evaporate a few mL on a steam bath to dryness, and ignite gently to volatilize any free iodine: the residue responds to the tests for
Potassium 
191
and for
Iodide 191.
Assay for iodine—
Transfer 10.0 mL of Solution into a glass-stoppered, 500-mL flask, add 10 mL of water, and titrate with 0.1 N sodium thiosulfate VS, adding 3 mL of
starch TS as the endpoint is approached. Each mL of 0.1 N sodium thiosulfate is equivalent to 12.69 mg of I.
Assay for potassium iodide—
Transfer 10.0 mL of Solution to a glass-stoppered, 500-mL flask, add 30 mL of water and 50 mL of hydrochloric acid, cool to room temperature, and titrate with 0.05
M potassium iodate VS until the dark brown solution that is produced becomes pale brown. Add 1 mL of amaranth TS, and continue the titration slowly until the red color just changes to yellow. The difference between the number of mL of 0.05
M potassium iodate used and half the number of mL of 0.1 N sodium thiosulfate used in the
Assay for iodine, multiplied by 16.60, represents the number of mg of KI in the volume of the Solution taken.
