Alanine
;)
L-Alanine.
L-Alanine [56-41-7].
»Alanine contains not less than 98.5percent and not more than 101.5percent of C3H7NO2,as L-alanine,calculated on the dried basis.
Packaging and storage—
Preserve in tight containers,and store at controlled room temperature.
Identification,Infrared Absorption á197Kñ.
Specific rotation á781Sñ:
between +13.7
and +15.1.
and +15.1.
Test solution:
100mg per mL,in 6Nhydrochloric acid.
pHá791ñ:
between 5.5and 7.0in a solution (1in 20).
Loss on drying á731ñ—
Dry it at 105for 3hours:it loses not more than 0.2%of its weight.
for 3hours:it loses not more than 0.2%of its weight.
Residue on ignition á281ñ:
not more than 0.15%.
Chloride á221ñ—
A1.0-g portion shows no more chloride than corresponds to 0.70mLof 0.020Nhydrochloric acid (0.05%).
Sulfate á221ñ—
A1.0-g portion shows no more sulfate than corresponds to 0.30mLof 0.020Nsulfuric acid (0.03%).
Iron á241ñ:
0.003%.
Heavy metals,Method Iá231ñ:
0.0015%.
Chromatographic purity—
Adsorbent:
0.25-mm layer of chromatographic silica gel mixture.
Test solution—
Dissolve an accurately weighed quantity of Alanine in water to obtain a solution having a concentration of 10mg per mL.Apply 5µL.
Standard solution—
Dissolve an accurately weighed quantity of USPL-Alanine RSin water to obtain a solution having a known concentration of about 0.05mg per mL.Apply 5µL.[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 0.4mg each of USPL-Alanine RSand USP Glycine RSper mL.Apply 5µL.
Spray reagent—
Dissolve 0.2g of ninhydrin in 100mLof a mixture of butyl alcohol and 2Nacetic acid (95:5).
Developing solvent system—
Prepare a mixture of butyl alcohol,glacial acetic acid,and water (60:20:20).
Procedure—
Proceed as directed forThin-Layer Chromatography underChromatography á621ñ.After air-drying the plate,repeat the development process.After air-drying a second time,spray withSpray reagent,and heat between 100and 105for about 15minutes.Examine the plate under white light.The chromatogram obtained from theSystem suitability solution exhibits two clearly separated spots.Any secondary spot in the chromatogram obtained from theTest solution is not larger or more intense than the principal spot in the chromatogram obtained from theStandard solution:not more than 0.5%of any individual impurity is found,and not more than 2.0%of total impurities is found.
and 105for about 15minutes.Examine the plate under white light.The chromatogram obtained from theSystem suitability solution exhibits two clearly separated spots.Any secondary spot in the chromatogram obtained from theTest solution is not larger or more intense than the principal spot in the chromatogram obtained from theStandard solution:not more than 0.5%of any individual impurity is found,and not more than 2.0%of total impurities is found.
Organic volatile impurities,Method Iá467ñ:
meets the requirements.
Assay—
Transfer about 80mg of Alanine,accurately weighed,to a 125-mLflask,dissolve in a mixture of 3mLof formic acid and 50mLof glacial acetic acid,and titrate with 0.1Nperchloric acid VS,determining the endpoint potentiometrically.Perform a blank determination,and make any necessary correction.Each mLof 0.1Nperchloric acid is equivalent to 8.909mg of C3H7NO2.
Auxiliary Information—
Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist
Expert Committee:(DSN)Dietary Supplements:Non-Botanicals
USP28–NF23Page 54
Pharmacopeial Forum:Volume No.27(5)Page 2973
Phone Number:1-301-816-8389