Specification Test Results

• Appearance:
  Yellow to beige to light brown Powder
• Infrared spectrum:
  Conforms
• Solubility:
  (0.1 % in ethanol) Clear
• UV Lambda max:
  613 to 621 nm (in buffer)
• Specific extinction E (1%/1cm):
  ≥550 (at lambda max)
• Visual transition interval:
  from pH 3.8 (yellow) to pH 5.4 (blue)
• Heavy metals (as Pb):
  ≤10 ppm