Products / pH Indicators


C.A.S. No. 76-61-9
M.F. C27H30O5S
M.W. 466.60gm/mole


Dye Content (by Spectrophotometry) >95%
Solubility 0.1 % (95% EtOH) Clear solution
Transition range pH7.8-9.5
Absorption Maximum (pH 7.8) ?1max 431-436nm
Absorption maximum (pH 9.5) ?2max 594-598nm
Absorptivity (A1%/1cm at pH 7.8 at ?1max) 200-300
Absorptivity (A1%/1cm at pH 9.5 at ?2max) 450-550
Loss on drying (110°C) <3%

Chemical Name

Phenol, 4,4'-(3H-2,1-benzoxathiol-3-ylidene)bis[5-methyl-2-(1-methylethyl)-, S,S-dioxide

InChI Key



Soluble in alcohol, water (sparingly), and 0.1N HCl/ethanol.

Product Description:

Thymol Blue is a pH indicator with visual transition intervals of pH 1.2 (red) to pH 2.8 (yellow), and pH 8.0 (yellow) to pH 9.2 (blue). Water soluble pH indicator Thymol Blue sodium salt acts as a pH indicator and utilized to indicate the changes in pH. It is involved in the ionization in multi-component drug formulation


A pH optode based on thymol blue: application to determination of CO2 using flow injection analysis systems. Thymol blue is used as a pH indicator. It is insoluble in water but soluble in alcohol and dilute alkali solutions. It transitions from red to yellow at pH 1.2–2.8 and from yellow to blue at pH 8.0–9.6. It is usually a component of Universal indicator Thymol Blue sodium salt was used to indicate the changes in pH to reflect ionization in multi-component drug formulations. General description.

Sitemap | Site Managed By - Fecund Technologies Pvt. Ltd.