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.
Identification—
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).
Chloride 221—
A 280-mg portion shows no more chloride than corresponds to 1.0 mL of 0.020 N hydrochloric acid (0.25%).
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—
Staff Liaison :
Catherine Sheehan, B.Sc., Scientist
Expert Committee : (EM105) Excipient Monographs 1
USP29–NF24 Page 3377
Pharmacopeial Forum : Volume No. 28(3) Page 826
Phone Number : 1-301-816-8262
