- Synonyms: Basic blue 17, Toluidine blue O - C15H16ClN3S - M = 305,83 g/mol - CAS [92-31-9] - EINECS-No.: 202-146-2 - Solub. in water: (25 ºC): 30 g/l - Tariff number: 3204 13 00 90 - Applications: indicator (microscopy), manufacture of dyes. SPECIFICATIONS Absorption maximum l (in H2O): 628 - 633 nm Absorptivity (A1%/1 cm; l max.): min. 1050 loss on drying (110 ºC): max. 8 %