C6H11NaO7 218.14

d-Gluconic acid, monosodium salt.
Monosodium d-gluconate [527-07-1].

Packaging and storage— Preserve in well-closed containers.

USP Reference standards 11—
USP Potassium Gluconate RS.

Identification—

Chloride 221— A 1.0-g portion shows no more chloride than corresponds to 1 mL of 0.020 N hydrochloric acid (0.07%).

Sulfate 221— A 2.0-g portion dissolved in boiling water shows no more sulfate than corresponds to 1 mL of 0.020 N sulfuric acid (0.05%).

Lead 251— Dissolve 1.0 g in 25 mL of water: the limit is 0.001%.

Heavy metals, Method I 231— Dissolve 1.0 g in 10 mL of water, add 6 mL of 3 N hydrochloric acid, and dilute with water to 25 mL: the limit is 0.002%.

Reducing substances— Transfer 1.0 g to a 250-mL conical flask, dissolve in 10 mL of water, and add 25 mL of alkaline cupric citrate TS. Cover the flask, boil gently for 5 minutes, accurately timed, and cool rapidly to room temperature. Add 25 mL of 0.6 N acetic acid, 10.0 mL of 0.1 N iodine VS, and 10 mL of 3 N hydrochloric acid, and titrate with 0.1 N sodium thiosulfate VS, adding 3 mL of starch TS as the endpoint is approached. Perform a blank determination, omitting the specimen, and note the difference in volumes required. Each mL of the difference in volume of 0.1 N sodium thiosulfate consumed is equivalent to 2.7 mg of reducing substances (as dextrose): the limit is 0.5%.

Assay— Transfer about 150 mg of Sodium Gluconate, accurately weighed, to a suitable conical flask, and dissolve in 75 mL of glacial acetic acid, warming if necessary to effect complete solution. Cool, add quinaldine red TS, and titrate with 0.1 N perchloric acid VS to a colorless endpoint. Each mL of 0.1 N perchloric acid is equivalent to 21.81 mg of C6H11NaO7.

Topic/Question	Contact	Expert Committee
Monograph	Elena Gonikberg, Ph.D. Senior Scientist 1-301-816-8251	(MDGRE05) Monograph Development-Gastrointestinal Renal and Endocrine
Reference Standards	Lili Wang, Technical Services Scientist 1-301-816-8129 RSTech@usp.org

USP32–NF27 Page 3576