l-Glutamic Acid, Hydrochloride

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

• Infrared Absorption

197K

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

USP l-Glutamic Acid, Hydrochloride RS

Auxiliary Information— Please check for your question in the FAQs before contacting USP.

Topic/Question	Contact	Expert Committee
Monograph	Robert H. Lafaver, M.S. Scientific Liaison 1-301-816-8335	(EXC2010) Monographs - Excipients
Reference Standards	RS Technical Services 1-301-816-8129 rstech@usp.org

USP35–NF30 Page 1810

Pharmacopeial Forum: Volume No. 35(5) Page 1203