Magnesium Gluconate
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C12H22MgO14·xH2O (anhydrous) 414.60

d-Gluconic acid, magnesium salt (2:1), hydrate.
Magnesium d-gluconate (1:2) hydrate.
Magnesium d-gluconate (1:2) dihydrate 450.64 [59625-89-7].

Anhydrous [3632-91-5].
» Magnesium Gluconate contains not less than 98.0 percent and not more than 102.0 percent of C12H22MgO14, calculated on the anhydrous basis.
Packaging and storage— Preserve in well-closed containers.
A: A solution (1 in 10) responds to the tests for Magnesium 191.
B: It responds to Identification test B under Calcium Gluconate.
pH 791: between 6.0 and 7.8, in a solution (1 in 20).
Water, Method Ib 921: between 3.0% and 12.0%, 30 minutes being allowed for solubilization of the specimen and for the reaction to reach completion, and a blank determination being performed with the same volume of Reagent but without the specimen. Calculate the water content of the specimen, in mg, taken by the formula:
F(X b X)R,
in which Xb is the volume, in mL, of standardized Water-Methanol Solution required to neutralize the unconsumed Reagent in the blank determination; and the other terms are as defined therein.
Chloride 221 A 1.0-g portion shows no more chloride than corresponds to 0.70 mL of 0.020 N hydrochloric acid (0.05%).
Sulfate 221 A 2.0-g portion shows no more sulfate than corresponds to 1.0 mL of 0.020 N sulfuric acid (0.05%).
Heavy metals 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 1.0%.
Assay— Weigh accurately about 800 mg of Magnesium Gluconate, dissolve in 20 mL of water, add 5 mL of ammonia-ammonium chloride buffer TS and 0.1 mL of eriochrome black TS, and titrate with 0.05 M edetate disodium VS to a blue endpoint. Each mL of 0.05 M edetate disodium is equivalent to 20.73 mg of C12H22MgO14.
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Topic/Question Contact Expert Committee
Monograph Curtis Phinney

(DSN05) Dietary Supplements - Non-Botanicals
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 2833
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.