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C5H10N2O3 146.14

2-Aminoglutaramic acid [56-85-9].
» Glutamine contains not less than 98.5 percent and not more than 101.5 percent of C5H10N2O3, calculated on the dried basis.
Packaging and storage— Preserve in well-closed containers, and store at controlled room temperature.
Specific rotation 781S: between +6.3 and +7.3, determined at 20.
Test solution— In a suitable flask, accurately prepare a solution of about 40 mg per mL in water at about 40. Cool and dilute with water to volume before use.
Loss on drying 731 Dry it at 105 for 3 hours: it loses not more than 0.3% of its weight.
Residue on ignition 281: not more than 0.3%.
Chloride 221 A 0.7-g portion shows no more chloride than corresponds to 0.50 mL of 0.020 N hydrochloric acid: not more than 0.05% is found.
Sulfate 221 A 0.8-g portion shows no more sulfate than corresponds to 0.25 mL of 0.020 N sulfuric acid: not more than 0.03% is found.
Iron 241: 0.003%.
Chromatographic purity—
Adsorbent: 0.25-mm layer of chromatographic silica gel mixture.
Test solution: 10 mg per mL, in water.
Standard solution— Prepare a solution of USP Glutamine RS in water having a known concentration of about 0.05 mg per mL.
Application volume: 5 µL.
Developing solvent system: a mixture of butyl alcohol, water, and glacial acetic acid (3:1:1).
Spray reagent— Dissolve 0.2 g of ninhydrin in 100 mL of a mixture of butyl alcohol and 2 N acetic acid (95:5).
Procedure— Proceed as directed for Thin-layer chromatography under Chromatography 621, then dry the plate at 80 for 30 minutes. Spray the plate with the Spray reagent, heat at 80 for 10 minutes, and examine under white light: no secondary spot in the chromatogram obtained from the Test solution is larger or more intense than the principal spot in the chromatogram obtained from the Standard solution (0.5%).
Assay— Transfer about 150 mg of Glutamine, accurately weighed, to a 125-mL flask, dissolve in 3 mL of formic acid and 50 mL of glacial acetic acid, and titrate with 0.1 N perchloric acid VS, determining the endpoint potentiometrically. Perform a blank determination, and make any necessary correction (see Titrimetry 541). Each mL of 0.1 N perchloric acid is equivalent to 14.615 mg of C5H10N2O3.
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Topic/Question Contact Expert Committee
Monograph Curtis Phinney

(DSN05) Dietary Supplements - Non-Botanicals
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 2508