Glutamine
C5H10N2O3 146.14
l-Glutamine;
2-Aminoglutaramic acid
[56-85-9].
(gloo' ta meen).
+'&img=../../images/v35300/cas-56-85-9.gif&casNumber=56-85-9&usp=35&nf=30&chemicalStructureImage=true&ID='+parent.myID,600,500);)
C5H10N2O3 146.14
l-Glutamine;
2-Aminoglutaramic acid
[56-85-9].DEFINITION
Glutamine contains NLT 98.5% and NMT 101.5% of l-glutamine (C5H10N2O3), calculated on the dried basis.
IDENTIFICATION
ASSAY
• Procedure
Sample:
150 mg of Glutamine
Blank:
Mix 3 mL of formic acid and 50 mL of glacial acetic acid.
Titrimetric system
(See Titrimetry 
541
.)
541.)
Mode:
Direct titration
Titrant:
0.1 N perchloric acid VS
Endpoint detection:
Potentiometric
Analysis:
Dissolve the Sample in 3 mL of formic acid and 50 mL of glacial acetic acid, and titrate with the Titrant. Perform a Blank determination.
Calculate the percentage of glutamine (C5H10N2O3) in the Sample taken:
Result = {[(VS 
VB) × N × F]/W} × 100
VB) × N × F]/W} × 100| VS | = | = volume of Titrant consumed by the Sample (mL) |
| VB | = | = volume of Titrant consumed by the Blank (mL) |
| N | = | = actual normality of the Titrant (mEq/mL) |
| F | = | = equivalency factor, 146.1 mg/mEq |
| W | = | = Sample weight (mg) |
Acceptance criteria:
98.5%–101.5% on the dried basis
IMPURITIES
• Residue on Ignition 281:
NMT 0.3%
281:
NMT 0.3%
• Chloride and Sulfate, Chloride 221
221
Standard solution:
0.50 mL of 0.020 N hydrochloric acid
Sample:
0.7 g of Glutamine
Acceptance criteria:
NMT 0.05%
• Chloride and Sulfate, Sulfate 221
221
Standard solution:
0.25 mL of 0.020 N sulfuric acid
Sample:
0.8 g of Glutamine
Acceptance criteria:
NMT 0.03%
• Iron 241:
NMT 30 ppm
241:
NMT 30 ppm
• Heavy Metals, Method I 231:
NMT 15 ppm
231:
NMT 15 ppm
• Related Compounds
Standard solution:
0.05 mg/mL of USP Glutamine RS in water
Sample solution:
10 mg/mL of Glutamine in water
Chromatographic system
Mode:
TLC
Adsorbent:
0.25-mm layer of chromatographic silica gel mixture
Application volume:
5 µL
Developing solvent system:
Butyl alcohol, glacial acetic acid, and water (3:1:1)
Spray reagent:
2 mg/mL of ninhydrin in a mixture of butyl alcohol and 2 N acetic acid (95:5)
Analysis:
Dry the plate at 80
for 30 min. Spray the plate with Spray reagent, heat at 80 for 10 min, and examine under white light.
for 30 min. Spray the plate with Spray reagent, heat at 80 for 10 min, and examine under white light.
Acceptance criteria:
No secondary spot of the Sample solution is larger or more intense than the principal spot of the Standard solution (NMT 0.5%).
SPECIFIC TESTS
• Optical Rotation, Specific Rotation 781S
781S
Sample solution:
40 mg/mL in water. Warm at 40 to dissolve.
to dissolve.
Analysis:
Proceed as directed in the chapter, except measure at 20.
.
Acceptance criteria:
+6.3 to +7.3
to +7.3
• Loss on Drying 731:
Dry a sample at 105 for 3 h: it loses NMT 0.3% of its weight.
731:
Dry a sample at 105 for 3 h: it loses NMT 0.3% of its weight.
ADDITIONAL REQUIREMENTS
• Packaging and Storage:
Preserve in well-closed containers, and store at controlled room temperature.
• USP Reference Standards 11
11
USP Glutamine RS 
') + '&img=../../images/v35300/cas-56-85-9.gif',600,500);)
Auxiliary Information—
Please check for your question in the FAQs before contacting USP.
| Topic/Question | Contact | Expert Committee |
|---|---|---|
| Monograph | Huy T. Dinh, M.S.
Scientific Liaison 1-301-816-8594 |
(DS2010) Monographs - Dietary Supplements |
| Reference Standards | RS Technical Services 1-301-816-8129 rstech@usp.org |
USP35–NF30 Page 3346