Description

Thymol Blue is a versatile and highly sensitive pH indicator dye, widely recognized for its distinct color transitions across multiple pH ranges. This compound is essential for precise analytical chemistry, providing a reliable visual endpoint in titrations and a critical tool for monitoring acidity or alkalinity in various systems. It is primarily utilized by professionals in pharmaceutical quality control, chemical manufacturing, academic research, and water treatment facilities for accurate pH determination and process monitoring.

Application

• pH Indicator in Titrations: Used as a visual endpoint indicator in acid-base titrations, particularly effective in the pH range of 1.2-2.8 (red to yellow) and 8.0-9.6 (yellow to blue).
• Microbiological & Cell Culture Media: Incorporated into growth media as a pH indicator to monitor metabolic activity and acid production.
• Analytical Chemistry Reagent: Serves as a key component in test kits, buffer solutions, and laboratory reagents for qualitative and quantitative analysis.
• Educational & Research Laboratories: Employed in teaching demonstrations and research experiments to illustrate pH concepts and chemical equilibria.
• Industrial Process Monitoring: Applied in chemical synthesis and manufacturing processes to visually track pH changes in real-time.
• Water Quality Testing: Used in environmental monitoring to assess the pH of water samples and effluents.

Basic Information

Product Name	Thymol Blue
CAS No.	76-61-9
Molecular Formula	C27H30O5S
Molecular Weight	466.59 g/mol
Synonyms	Thymolsulfonephthalein; Thymol Blue Indicator; 4,4'-(3H-2,1-Benzoxathiol-3-ylidene)bis(5-methyl-2-(1-methylethyl)phenol) S,S-dioxide; 3,3-Bis[4-hydroxy-2-methyl-5-(1-methylethyl)phenyl]-1(3H)-isobenzofuranone; NSC 6691; Thymol Blue pH Indicator; Acid-base Indicator Blue.
EINECS	200-973-3

Quality Control

Our Thymol Blue is manufactured under strict quality management systems to ensure batch-to-batch consistency and high purity. Each lot undergoes comprehensive analytical testing, including identity confirmation, purity assay, and verification of performance as a pH indicator. A Certificate of Analysis (COA) detailing all test results is provided with every shipment to guarantee compliance with your specifications and industry standards.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, well-ventilated area at controlled room temperature (15-25°C). Keep away from heat, sparks, and open flame.

Specification

Item	Specification
Appearance	Dark green powder or crystals
Identification (IR)	Conforms
Melting Point	221 - 224 °C
pH Transition Range	1.2 (red) - 2.8 (yellow); 8.0 (yellow) - 9.6 (blue)
Solubility	Soluble in alcohol, alkali; slightly soluble in water
Loss on Drying	≤ 1.0 %
Assay (HPLC)	≥ 98.0 %

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.