Identity (UV/VIS-Spectrum): passes test

Appearance: White to yellowish white powder

Clarity of the alkoholic solution (10 g/l ethanol): passes test

Absorption maximum λmax. (buffer pH 9.8): 551 - 554 nm

Spec. Absorptivity A 1%/1cm (λmax; 0.01 g/l; buffer pH 9.8; calculated on dried substance): 700 - 750

Transition range: pH 8.2 - pH 9.8 almost colorless - red-violet

Transition range (according to ACS): passes test

Transition interval (according Reag. Ph Eur): passes test

Loss on drying (105 °C): ≤ 1 %