L-组氨酸 98%

Specification Test Results

• Appearance:
  White Crystalline powder or crystals
• Infrared spectrum:
  Conforms
• Loss on drying:
  ≤0.2 % (105°C, 3 h)
• Sulfated ash:
  ≤0.1 %
• UV transmittance:
  ≥98 % (c=5, H2O, 430 nm) 1 cm cell
• pH:
  7.0 to 8.5 (2 % in water)
• Specific optical rotation:
  +12.0° to +14.0° (20°C, 589 nm) (c=11, 6 N HCl) (on dry substance)
• Titration with HClO4:
  97.5 to 102.5 % (On dry substance)
• Chloride (Cl):
  ≤200 ppm
• Sulfate (SO4):
  ≤200 ppm
• Ammonium (NH4):
  ≤200 ppm
• Iron (Fe):
  ≤10 ppm
• Heavy metals (as Pb):
  ≤10 ppm