l-Glutamic Acid, Hydrochloride
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C5H9NO4·HCl 183.59
l-2-Aminoglutaric acid, hydrochloride;    
2-Aminopentanedioic acid, hydrochloride     [138-15-8].
DEFINITION
l-Glutamic Acid, Hydrochloride, contains NLT 98.5% and NMT 101.5% of C5H9NO4·HCl, calculated on the dried basis.
IDENTIFICATION
ASSAY
•  Procedure
Sample:  100 mg of l-Glutamic Acid, Hydrochloride, previously dried
Analysis:  Dissolve the Sample in 0.5 mL of water, add 15.0 mL of 0.1 N perchloric acid VS, and heat on a water bath for 30 min. After cooling, add 45 mL of glacial acetic acid, and titrate the excess perchloric acid with 0.1 N sodium acetate, determining the endpoint potentiometrically. Perform a blank determination (see Titrimetry 541). Each mL of 0.1 N perchloric acid is equivalent to 18.36 mg of C5H9NO4·HCl.
Acceptance criteria:  98.5%–101.5% on the dried basis
IMPURITIES
Inorganic Impurities 
•  Residue on Ignition 281: NMT 0.25%
•  Heavy Metals, Method I 231: NMT 5 ppm
SPECIFIC TESTS
•  Optical Rotation, Specific Rotation 781S: +25.2 to +25.8, determined at 20
Sample solution:  100 mg/mL, in 2 N hydrochloric acid
•  Loss on Drying 731: Dry a sample at 80 for 4 h: it loses NMT 0.5% of its weight.
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Store in well-closed, light-resistant containers.
•  USP Reference Standards 11
USP l-Glutamic Acid, Hydrochloride RS
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USP35–NF30 Page 1810
Pharmacopeial Forum: Volume No. 35(5) Page 1203