Aspartic Acid, chemical structure, molecular formula, Reference Standards

Aspartic Acid

C4H7NO4 133.10
L-Aspartic acid.
L-Aspartic acid [56-84-8].

»Aspartic Acid contains not less than 98.5percent and not more than 101.5percent of C4H7NO4,calculated on the dried basis.

Packaging and storage— Preserve in well-closed containers,protected from light.

USP Reference standards á11ñ— USP Aspartic Acid RS.

Identification, Infrared Absorption á197Kñ.

Specific rotation á781Sñ: between +24.0

and +26.0

,at 20

Test solution: 80mg per mL,in 6Nhydrochloric acid.

Loss on drying á731ñ— Dry it at 105

for 3hours:it loses not more than 0.5%of its weight.

Residue on ignition á281ñ: not more than 0.1%.

Chloride á221ñ— Dissolve 0.7g in 3mLof diluted nitric acid,and dilute with water to make 15mL:the solution shows no more chloride than corresponds to 0.20mLof 0.020Nhydrochloric acid (0.02%).

Sulfate á221ñ— Dissolve 0.8g in 4mLof hydrochloric acid,and dilute with water to make 15mL:the solution shows no more sulfate than corresponds to 0.25mLof 0.020Nsulfuric acid (0.03%).

Iron á241ñ: 0.001%.

Heavy metals,Method IIá231ñ: 0.001%.

Chromatographic purity—

Adsorbent: 0.25-mm layer of chromatographic silica gel mixture.

System suitability solution— Dissolve 10mg each of USP Aspartic Acid RSand glutamic acid,each accurately weighed,in 2mLof ammonia TS,dilute with water to 25.0mL,and mix.

Test solution— Transfer 0.1g of Aspartic Acid to a 10-mLvolumetric flask,dissolve in 2mLof 17%ammonia solution (prepared by diluting ammonium hydroxide,6in 10),dilute with water to volume,and mix.

Standard solution— Transfer 5mg of USP Aspartic Acid RSto a 100-mLvolumetric flask,dissolve in 2mLof 17%ammonia solution (prepared by diluting ammonium hydroxide,6in 10),ammonium hydroxide,dilute with water to volume,and mix.

Application volume: 5µL.

Developing solvent system: a mixture of butyl alcohol,glacial acetic acid,and water (6:2:2).

Spray reagent— Dissolve 0.2g of ninhydrin in 100mLof a mixture of butyl alcohol and 2Nacetic acid (95:5).

Procedure— Proceed as directed for Thin-Layer Chromatographyunder Chromatography á621ñ,except to dry the plate at 80

for 30minutes,spray with Spray reagent,and heat at 80

for 30minutes.Examine the plate under white light.The chromatogram obtained from the System suitability solutionexhibits two clearly separated spots,and no secondary spot in the chromatogram of the Test solutionis larger or more intense than the principal spot in the chromatogram of 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.

Organic volatile impurities,Method IVá467ñ: meets the requirements.

Standard solution— Prepare a solution in organic-free water containing,in each mL,2.4µg of methylene chloride,1.5µg of 1,4-dioxane,0.32µg of trichloroethylene,and 0.24µg of chloroform.Prepare fresh daily.

Test solution— Dissolve an accurately weighed portion of the material in organic-free water with the aid of a water bath at about 45

if necessary,to obtain a final solution having a known concentration of about 4mg per mL.

Assay— Transfer about 0.1g of Aspartic Acid,accurately weighed,to a 125-mLflask,and dissolve in 50mLof carbon dioxide-free water,heating slightly if necessary.Cool,add 0.1mLof bromothymol blue TS,and titrate with 0.1Nsodium hydroxide VSuntil the color changes from yellow to blue.Perform a blank determination,and make any necessary correction (see Titrimetry á541ñ).Each mLof 0.1Nsodium hydroxide is equivalent to 13.31mg of C4H7NO4.

Auxiliary Information— Staff Liaison:Lawrence Evans,III,Ph.D.,Scientist

Expert Committee:(DSN)Dietary Supplements:Non-Botanicals

USP28–NF23Page 179

Pharmacopeial Forum:Volume No.30(4)Page 1163

Phone Number:1-301-816-8389