Lysine Acetate
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C6H14N2O2·C2H4O2 206.24

l-Lysine monoacetate.
l-Lysine monoacetate [57282-49-2].
» Lysine Acetate contains not less than 98.0 percent and not more than 102.0 percent of C6H14N2O2·C2 H4O2, as l-lysine acetate, calculated on the dried basis.
Packaging and storage— Preserve in well-closed containers.
Identification, Infrared Absorption 197K.
Specific rotation 781S: between +8.4 and +9.9.
Test solution: 100 mg per mL, in water.
Loss on drying 731 Dry it at 80 for 3 hours: it loses not more than 0.2% of its weight.
Residue on ignition 281: not more than 0.4%.
Chloride 221 A 0.73-g portion shows no more chloride than corresponds to 0.50 mL of 0.020 N hydrochloric acid (0.05%).
Sulfate 221 A 0.33-g portion shows no more sulfate than corresponds to 0.10 mL of 0.020 N sulfuric acid (0.03%).
Iron 241: 0.003%.
Chromatographic purity—
Adsorbent: 0.25-mm layer of chromatographic silica gel mixture.
Test solution— Dissolve an accurately weighed quantity of Lysine Acetate in water to obtain a solution having a concentration of 10 mg per mL. Apply 5 µL.
Standard solution— Dissolve an accurately weighed quantity of USP l-Lysine Acetate RS in water to obtain a solution having a known concentration of about 0.05 mg per mL. Apply 5 µL. [note—This solution has a concentration equivalent to about 0.5% of that of the Test solution.]
System suitability solution— Prepare a solution in water containing 0.4 mg each of USP l-Lysine Acetate RS and USP Arginine Hydrochloride RS per mL. Apply 5 µL.
Spray reagent— Dissolve 0.2 g of ninhydrin in 100 mL of a mixture of butyl alcohol and 2 N acetic acid (95:5).
Developing solvent system— Prepare a mixture of isopropyl alcohol and ammonium hydroxide (70:30).
Procedure— Proceed as directed for Thin-Layer Chromatography under Chromatography 621. Dry the plate between 100 and 105 until the ammonia completely disappears. Spray with Spray reagent, and heat between 100 and 105 for about 15 minutes. Examine the plate under white light. The chromatogram obtained from the System suitability solution exhibits two clearly separated spots. Any secondary spot in the chromatogram obtained from the Test solution is not larger or more intense than the principal spot in the chromatogram obtained from the Standard solution: not more than 0.5% of any individual impurity is found; and not more than 2.0% of total impurities is found.
Assay— Transfer about 100 mg of Lysine Acetate, accurately weighed, to a 125-mL flask, dissolve in a mixture of 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. Each mL of 0.1 N perchloric acid is equivalent to 10.31 mg of C6H14N2O2·C2H4O2.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Curtis Phinney

(DSN05) Dietary Supplements - Non-Botanicals
Reference Standards Lili Wang, Technical Services Scientist
USP32–NF27 Page 2818
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.