- Synonyms: BPB, 3,3',5,5'-Tetrabromophenolsulfonphthaleinr- C19H10Br4O5Sr- M = 669,96 g/molr- CAS [115-39-9]r- EINECS-No.: 204-086-2r- Solub. in water: (20 ºC): almost insolubler- Melting point: 273 ºC (decomposes)r- Tariff number: 2934 99 90 90r- Applications: analytical chemistry, indicator.rrSPECIFICATIONSrrto blue-violet) : 3,1 - 4,4 rAbsorption maximum l1 (pH 3,0) : 434 - 439 nm rAbsorption maximum l2 (pH 4,6) : 590 - 593 nm rAbsorptivity (A1%/1 cm; l1; pH 3,0 on dried sample): 350 - 385 rAbsorptivity (A1%/1 cm; l2; pH 4,6 on dried sample): 940 - 1000 rtransition range acc. ACS : passes testrloss on drying (110 ºC): max. 1 %r