1.03023

Bromophenol red

pH indicator

• Synonym(s): Bromophenol red, 3′,3′′-Dibromophenolsulfonphthalein, BPR
• Empirical Formula (Hill Notation): C₁₉H₁₂Br₂O₅S
• CAS Number: 2800-80-8
• Molecular Weight: 512.17
• UNSPSC Code: 12171502
• EC Index Number: 220-538-1
• NACRES: NA.21

Properties

• product name: Bromophenol red, indicator
• Quality Level: 200
• form: solid
• impurities: ≤5% Water (Karl Fischer)
• visual transition interval: 4.7-6.3, yellow to purple
• mp: 230 °C (decomposition)
• bulk density: 770 kg/m³
• Amax: 435-440 nm (buffer pH 4.7); 574-577 nm (buffer pH 6.3)
• storage temp.: 2-30°C
• InChI: 1S/C19H12Br2O5S/c20-14-9-11(5-7-16(14)22)19(12-6-8-17(23)15(21)10-12)13-3-1-2-4-18(13)27(24,25)26-19/h1-10,22-23H
• InChI key: OYCLSQDXZMROJK-UHFFFAOYSA-N

Description

Analysis Note

Identity (UV/VIS-Spectrum): passes test
Transition range: pH 4.7 - pH 6.3 yellow to purple
Absorption maximum λ 1 (buffer pH 4.7): 435 - 440 nm
Absorption maximum λ 2 (buffer pH 6.3): 574 - 577 nm
Spec. Absorptivity A 1%/1cm (λ1_max; 0.01 g/l; buffer pH 4.7; calculated on anhydrous substance): ≥ 380
Spec. Absorptivity A 1%/1cm (λ2_max; 0.01 g/l; Puffer pH 6.3; calculated on anhydrous substance): ≥ 760
Water (according to Karl Fischer): ≤ 5 %

Safety Information

• Storage Class: 11 - Combustible Solids
• wgk_germany: WGK 3
• flash_point_f: Not applicable
• flash_point_c: Not applicable