Formula: C₂₁H₁₈O₅S CAS: 1733-12-6 EC No.: 217-076-3 M (Molar Mass): 382.43 g/mol pH Transition Range: 7.2 (yellow) to 8.8 (red) λmax: 435 nm (acidic), 572 nm (basic)

Dye Content: ≥ 85% Appearance: Dark green to brown powder pH Transition: Clear change from yellow to red Loss on Drying: ≤ 1.0% Sulfated Ash: ≤ 0.5% Solubility: Soluble in ethanol, methanol; slightly soluble in water Indicator Performance: Satisfactory for pH determination Heavy Metals (as Pb): ≤ 20 ppm Absorbance (0.1% in ethanol): E₁%₁cm ≥ 250 at 572 nm