1.05225

Cresol red

pH indicator, Reag. Ph Eur

• Synonym(s): Cresol red, o-Cresolsulfonphthalein
• Empirical Formula (Hill Notation): C₂₁H₁₈O₅S
• CAS Number: 1733-12-6
• Molecular Weight: 382.43
• MDL number: MFCD00005878
• UNSPSC Code: 12171502
• EC Index Number: 217-064-2
• NACRES: NA.21

Properties

• product name: Cresol red, indicator Reag. Ph Eur
• agency: reag. Ph. Eur.
• Quality Level: 200
• form: solid
• loss: ≤5% loss on drying, 110°C
• visual transition interval: 0.5-2.5, pink to brownish-yellow(1st transition range); 6.5-8.5, yellow to purple(2nd transition range)
• mp: 290 °C (decomposes)
• bulk density: 600‑620 kg/m³
• storage temp.: 2-30°C
• InChI: 1S/C21H18O5S/c1-13-11-15(7-9-18(13)22)21(16-8-10-19(23)14(2)12-16)17-5-3-4-6-20(17)27(24,25)26-21/h3-12,22-23H,1-2H3
• InChI key: OBRMNDMBJQTZHV-UHFFFAOYSA-N

Description

Application

• Description of lipase producing novel yeast species Debaryomyces apis f.a., sp. nov. and a modified pH indicator dye-based method for the screening of lipase producing microorganisms.: This study introduces a novel yeast species, Debaryomyces apis, capable of producing lipase, and a new method utilizing Cresol Red as a pH indicator dye for screening lipase-producing microorganisms (Kumari et al., 2023).


• Application of colorimetric sensor in monitoring dissolved CO2 in natural waters.: This research discusses the use of a colorimetric sensor, which incorporates Cresol Red, for monitoring dissolved carbon dioxide in natural water sources, providing a method for environmental monitoring and analysis (Lee et al., 2022).


• Polymer Film Blend of Polyvinyl Alcohol, Trichloroethylene and Cresol Red for Gamma Radiation Dosimetry.: This article presents a polymer film blend incorporating Cresol Red for gamma radiation dosimetry, highlighting its application in monitoring radiation exposure (Doyan et al., 2021).


• Highly efficient colorimetric CO2 sensors for monitoring CO2 leakage from carbon capture and storage sites.: The study involves the development of highly efficient colorimetric sensors using Cresol Red for detecting CO2 leaks, critical for ensuring safety in carbon capture and storage operations (Ko et al., 2020).

Analysis Note

1st transition range: pH 0.5 - pH 2.5pink - brownish yellow
2nd transition range: pH 6.5 - pH 8.5yellow - purple
Appearance of solution: passes test
Loss on drying (110 °C): ≤ 5
Sensitivity test: passes test

Safety Information

• Storage Class: 11 - Combustible Solids
• wgk_germany: WGK 3