L-Phenylalanine CAS 63-91-2 (H-Phe-OH) Assay 98.5~101.5% Factory High Quality

L-Phenylalanine, when dried, contains not less than 98.5% of C9H11NO2.
Description L-Phenylalanine occurs as white crystals or crystalline powder. It is odorless or has a faint characteristic odor, and has a slightly bitter taste. It is freely soluble in formic acid, sparingly soluble in water, and practically insoluble in ethanol (95). It dissolves in dilute hydrochloride acid.
Identification Determine the infrared absorption spectrum of L-Phenylalanine, previously dried, as directed in the potassium bromide disk method under Infrared Spectrophotometry <2.25>, and compare the spectrum with the Reference Spectrum: both spectra exhibit similar intensities of absorption at the same wave numbers.
Optical Rotation <2.49> [a]D20: -33.0° to -35.59° (after drying, 0.5 g, water, 25 mL, 100 mm).
pH <2.54> Dissolve 0.20 g of L-Phenylalanine in 20 mL of water: the pH of this solution is between 5.3 and 6.3
Purity (1) Clarity and color of solution-Dissolve 0.5 g of L-Phenylalanine in 10 mL of 1 mol hydrochloric acid TS: the solution is clear and colorless.
(2) Chloride <1.03>-Perform the test with 0.5 g of L-Phenylalanine. Prepare the control solution with 0.30 mL of 0.01 mol/L hydrochloride acid VS (not more than 0.021%).
(3) Sulfate <1.14>-Perform the test with 0.6 g of L-Phenylalanine. Prepare the control solution with 0.35 mL of 0.005 mol/L sulfuric acid VS (not more than 0.028z).
(4) Ammonium <1.02>-Perform the test with 0.25 g of L-Phenylalanine. Prepare the control solution with 5.0 mL of Standard Ammonium Solution (not more than 0.02%).
(5) Heavy Metals <1.07>-Dissolve 1.0 g of L-Phenylalanine in 40 mL of water and 2 mL of dilute acetic acid by warming, cool, and add water to make 50 mL. Perform the test using this solution as the test solution. Prepare the control solution as follows: to 2.0 mL of Standard Lead Solution add 2 mL of dilute acetic acid and water to make 50 mL (not more than 20 ppm).
(6) Arsenic <1.11>-Dissolve 1.0 g of L-Phenylalanine in 5 mL of dilute hydrochloride acid and 15 mL of water, and perform the test with this solution as the test solution (not more than 2 ppm).
(7) Related Substances-Dissolve 0.10 g of L-Phenylalanine in 25 mL of water, and use this solution as the sample solution. Pipet 1 mL of the sample solution, and add water to make exactly 50 mL. Pipet 5 mL of this solution, add water to make exactly 20 mL, and use this solution as the standard solution. Perform the test with these solutions as directed under Thin-layer Chromatography <2.03>. Spot 5mL each of the sample solution and standard solution on a plate of silica gel for thin-layer chromatography. Develop the plate with a mixture of 1-butanol, water and acetic acid (100) (3:1:1) to adistance of about 10 cm, and dry the plate at 809Cfor30minutes. Spray evenly a solution of ninhydrin in acetone (1 in50) on the plate, and heat at 80℃ for 5 minutes: the spots other than the principal spot from the sample solution are not more intense than the spot from the standard solution.
Loss on Drying <2.41> Not more than 0.30% (1 g, 105℃, 3 hours).
Residue on Ignition <2.44> Not more than 0.10% (1 g).
Assay Weigh accurately about 0.17 g of L-Phenylalanine, previously dried, and dissolve in 3 mL of formic acid, add 50mL of acetic acid (100), and titrate <2.50> with 0.1 mol/L perchloric acid VS (potentiometric titration). Perform a blank determination, and make any necessary correction.
Each mL of 0.1 mol/L perchloric acid VS＝16.52 mg of C9H11NO2
Containers and storage Containers-Tight containers.