Specification Test Results

• Appearance:
  Red to Dark blue to Black powder to crystal
• Purity (HPLC):
  min. 98.0 area%
• Absorbance:
  min. 0.630 (5 mg/L, pH 9.2, 570.0 to 574.0 nm)
• Solubility in Sodium hydroxide solution:
  within almost transparency
• Transition interval (pH):
  (yellow)7.2 to 8.8 (red)