PhenylalanineEP8征求意见稿.doc

Reference: PA/PH/Exp. 10D/T (12) 6 ANP1 NOTE ON THE MONOGRAPH2 Ninhydrin-positive substances: TLC replaced by chromatography using an amino acids analyser which also allows quantification of ammonium.3 Assay: end-point determination by colour indicator replaced by potentiometric end-point determination.4 XXXX:07825 Phenylalanine6 Phenylalaninum7 8 C9H11NO29 Mr 165.210 [63-91-2]11 DEFINITION12 (2S)-2-Amino-3-phenylpropanoic acid.13 Fermentation product.14 Content: 98.5 per cent to 101.0 per cent (dried substance).15 CHARACTERS16 Appearance: white or almost white, crystalline powder, or shiny, white flakes.17 Solubility: sparingly soluble in water, very slightly soluble in ethanol (96 per cent). It dissolves in dilute mineral acids and in dilute solutions of alkali hydroxides.18 IDENTIFICATION19 First identification: A, B.20 Second identification: A, C, D.21 A. Specific optical rotation (see Tests).22 B. Infrared absorption spectrophotometry (2.2.24).23 Preparation: discs.24 Comparison: phenylalanine CRS. 25 C. Thin-layer chromatography (2.2.27).26 Test solution. Dissolve 10 mg of the substance to be examined in a mixture of equal volumes of glacial acetic acid R and water R and dilute to 50 mL with the same mixture of solvents.27 Reference solution. Dissolve 10 mg of phenylananine CRS in a mixture of equal volumes of glacial acetic acid R and water R and dilute to 50 mL with the same mixture of solvents.28 Plate: TLC silica gel plate R.29 Mobile phase: glacial acetic acid R, water R, butanol R (20:20:60 V/V/V).30 Application: 5 μL.31 Development: over 2/3 of the plate a path of 15 cm.32 Drying: at 105 °C until the ammonium disappears in air.33 Detection: spray with ninhydrin solution R and heat at 100-105 °C for 15 min.34 Results: the principal spot in the chromatogram obtained with the test solution is similar in position, colour and size to the principal spot in the chromatogram obtained with the reference solution.35 D. To about 10 mg add 0.5 g of potassium nitrat