C6H5K3O7·H2O 324.41

1,2,3-Propanetricarboxylic acid, 2-hydroxy-, tripotassium salt, monohydrate.
Tripotassium citrate monohydrate [6100-05-6].

Anhydrous 306.40 [866-84-2].

Packaging and storage— Preserve in tight containers.

Identification— A solution (1 in 10) responds to the tests for Potassium 191 and for Citrate 191.

Alkalinity— A solution of 1.0 g in 20 mL of water is alkaline to litmus, but after the addition of 0.20 mL of 0.10 N sulfuric acid, no pink color is produced by the addition of 1 drop of phenolphthalein TS.

Loss on drying 731— Dry it at 180 for 4 hours: it loses between 3.0% and 6.0% of its weight.

Tartrate— To a solution of 1 g in 1.5 mL of water in a test tube add 1 mL of 6 N acetic acid, and scratch the walls of the test tube with a glass rod: no crystalline precipitate is formed.

Heavy metals, Method I 231— Dissolve 2 g in 25 mL of water, and proceed as directed for Test Preparation, except to use glacial acetic acid to adjust the pH: the limit is 0.001%.

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

Residual solvents 467: meets the requirements.

Assay— Dissolve about 200 mg of Potassium Citrate, accurately weighed, in 25 mL of glacial acetic acid. Add 2 drops of crystal violet TS, and titrate with 0.1 N perchloric acid VS to a green endpoint. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 10.21 mg of C6H5K3O7.

Expert Committee : (DSN05) Dietary Supplements - Non-Botanicals

USP29–NF24 Page 1766

Phone Number : 1-301-816-8389