Monosodium Glutamate
» Monosodium Glutamate contains not less than 99.0 percent and not more than 100.5 percent of C5H8NNaO4·H2O.
Packaging and storage— Preserve in tight containers.
Clarity and color of solution— Dissolve 1.0 g in 10 mL of water. The solution is colorless and has no more turbidity (see Visual Comparison under Spectrophotometry and Light-scattering 851) than a standard mixture prepared as follows. To 0.2 mL of a solution of sodium chloride containing 10 µg of chloride ion (Cl) per mL, add 20 mL of water, and mix, then add 1 mL of 5 N nitric acid, 0.2 mL of dextrin solution (1 in 50), and 1 mL of silver nitrate TS, and allow to stand for 15 minutes.
A: To 1 mL of a solution (1 in 30) add 1 mL of ninhydrin TS and 100 mg of sodium acetate, and heat in a boiling water bath for 10 minutes: an intense, violet blue color is formed.
B: To 10 mL of a solution (1 in 10) add 5.6 mL of 1 N hydrochloric acid: a white, crystalline precipitate of glutamic acid is formed on standing. Precipitation is promoted by agitation. When 6 mL of 1 N hydrochloric acid is added to the turbid solution, the glutamic acid dissolves on stirring.
C: It responds to the pyroantimonate precipitate test for Sodium 191.
Specific rotation 781S: between +24.8 and +25.3 (t = 20).
Test solution: 100 mg per mL, in 2 N hydrochloric acid.
pH 791: between 6.7 and 7.2, in a solution (1 in 20).
Loss on drying 731 Dry it at 100 for 5 hours: it loses not more than 0.5% of its weight.
Chloride 221 A 280-mg portion shows no more chloride than corresponds to 1.0 mL of 0.020 N hydrochloric acid (0.25%).
Lead 251: 10 ppm.
Assay— Dissolve about 250 mg of Monosodium Glutamate, accurately weighed, then wetted with a few drops of water, in 100 mL of glacial acetic acid. Titrate with 0.1 N perchloric acid VS, determining the endpoint potentiometrically. Each mL of 0.1 N perchloric acid is equivalent to 9.356 mg of C5H8NNaO4·H2O.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Robert H. Lafaver, B.A.
(EM105) Excipient Monographs 1
USP32–NF27 Page 1285
Pharmacopeial Forum: Volume No. 28(3) Page 826
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.