- Synonyms: 3,3',5,5'-Tetrabromo-m-cresolsulfonphthalein, BCG - C21H14Br4O5S - M = 698,04 g/mol - CAS [76-60-8] - EINECS-No.: 200-972-8 - Tariff number: 2934 99 90 90 - Applications: analytical chemistry, indicator. SPECIFICATIONS pH range (yellow to blue): 3,8 - 5,4 Absorption maximum l1 (pH 3,5): 444 - 445 nm Absorption maximum l2 (pH 5,4): 615 - 618 nm Absorptivity (A1%/1 cm; l1, pH 3,5; on dried sample): 265 - 275 Absorptivity (A1%/1 cm; l2, pH 5,4; on dried sample): 530 - 570 loss on drying (110 ºC): max. 5 %