N-Acetyl-DL-Leucine CAS 99-15-0 (Ac-DL-Leu-OH; Acetylleucine) Assay 97.5~102.5% AJI92 Standard High Quality

N-Acetyl-DL-Leucine CAS: 99-15-0
Method of Analysis
1, Appearance:
The product is white crystals or crystalline powder. By visual.
2, Specific Rotation:
Take some goods, weighing precisely, adding methanol to dissolve and diluted into around 4g per 100ml of solution, 20℃ testing specific rotation -1.0°～+1.0°.
3, Transmittance:
Take 0.5g sample, adding 50ml Water to dissolve, according to the spectrophotometric method, testing the transmittance in the wavelength of 430nm not be less than 95.0%.
4, Heavy Metals:
Excepting other rules, take quantitative testing sample, making 25ml selected solution as request method. Additional taking specified amount of standard lead solution and 2ml acetate buffer solution (pH3.5), adding water or specified solution to dilute into 25ml and get the contrast solution. Respectively adding 2.0ml thioacetamide test solution in selected solution and contrast solution, shaking up, putting f o r 2min, making comparison in white background, the color of selected solution should be lighter than contrast solution. (Detection limit: 20ppm; Standard lead solution: Every 1ml is equal t o 10μg Pb 2+; Testing sample: 1.0g; Standard lead solution: 2.0ml).
5, Arsenic:
Take 2.0g sample, adding 5ml hydrochloric acid and 23ml water to dissolve, after testing, the result should conform (2ppm).
6, Loss on Drying:
Take some sample, In vacuum, at room temperatue for 3 hours, the loss weight should be less than 0.5%.
7, Residue on Ignition:
Take 1.0g~2.0g sample or the specified quantity, put it in the crucible of the ignition constant weight, precisely weigh, ignition slowly to completely carbonized, put till it is cool to room temperature. Unless otherwise specified, adding 0.5ml~1ml sulfuric made it wet, heating to steam clean sulfuric at the low temperature, ignition slowly to completely carbonized at the 700~800℃, displace it in the dryer, let it cool to the room temperature, precisely weigh, ignition to constant weight at the 700~800℃ then get it.
Residue on ignition%=(the weight of the residue and the crucible-the weight of the empty crucible)/the weight of the sample*100%
8, pH:
Take 0.5g sample, adding 50ml water to dissolve, testing pH1.7～3.0.
9, Assay:
Take about 140mg sample, anhydrous form, heat in boiling water to dissolve, using NaOH (0.1mol/L) to titrate. Every 1ml perchloric acid titrant is equal to 17.321mg testing samples. Calculating according to drying goods 97.5~102.5%.