K2CO3 (anhydrous) 138.21

Carbonic acid, dipotassium salt.
Dipotassium carbonate [584-08-7].

Sesquihydrate 165.23

Packaging and storage— Preserve in well-closed containers.

Identification— It responds to the tests for Potassium 191 and for Carbonate 191.

Loss on drying 731— Dry it at 180 for 4 hours: it loses not more than 0.5% of its weight.

Insoluble substances— Dissolve 1 g in 20 mL of water: the solution is complete, clear, and colorless.

Heavy metals 231— Dissolve 4.0 g in 10 mL of water, add 15 mL of 3 N hydrochloric acid, and heat to boiling. Add 1 drop of phenolphthalein TS, and neutralize with 1 N sodium hydroxide until the solution is faintly pink in color. Cool, and dilute with water to 25 mL: the limit is 0.0005%.

Organic volatile impurities, Method I 467: meets the requirements.

Residual solvents 467: meets the requirements.

Assay— Transfer the dried potassium carbonate obtained in the test for Loss on drying to a flask with the aid of 150 mL of water, add 4 drops of methyl orange TS, and titrate with 1 N hydrochloric acid VS. Each mL of 1 N hydrochloric acid is equivalent to 69.11 mg of K2CO3.

Expert Committee : (MDCV05) Monograph Development-Cardiovascular

USP29–NF24 Page 1759

Phone Number : 1-301-816-8305