Specification Test Results

• Appearance:
  Orange to Brown to Dark purple powder to crystal
• Purity (HPLC):
  min. 98.0 area%
• Absorbance:
  min. 0.350 (5 mg/L, EtOH, pH 6.6, 428.0 to 432.0 nm)
• Solubility in hot EtOH (95vol%):
  transparency
• Transition interval (pH):
  (purplish red)4.2 to 6.2 (yellow)