Description

o-Cresolphthalein is a high-purity organic compound widely used as a critical indicator and reagent in analytical chemistry. Its primary value lies in its distinct color change at specific pH ranges, making it an indispensable tool for precise titration and endpoint detection. This compound is essential for quality control and research laboratories in the pharmaceutical, chemical manufacturing, and water treatment industries.

Application

• pH Indicator in Titrations: Primarily used as a visual indicator for acid-base titrations, especially in the pH range of 8.2 (colorless) to 9.8 (red-violet).
• Complexometric Titrations: Employed as a metallochromic indicator for the titration of calcium and other metal ions with EDTA.
• Analytical Reagent: Serves as a key component in the preparation of specialized test kits and solutions for chemical analysis.
• Research & Development: Used in academic and industrial R&D for method development and studying reaction mechanisms.
• Water Hardness Testing: Applied in procedures to determine calcium concentration in water samples.
• Pharmaceutical Analysis: Utilized in QC labs for the assay of raw materials and finished products requiring precise pH measurement.

Basic Information

Product Name	o-Cresolphthalein
CAS No.	596-27-0
Molecular Formula	C22H18O4
Molecular Weight	346.38 g/mol
Synonyms	o-Cresolphthalein; 3,3-Bis(4-hydroxy-3-methylphenyl)-1(3H)-isobenzofuranone; 3',3''-Dimethylphenolphthalein; NSC 403079; Cresolphthalein (ortho-isomer); o-Cresolsulfonphthalein; 1(3H)-Isobenzofuranone, 3,3-bis(4-hydroxy-3-methylphenyl)-; o-CP
EINECS	209-882-1

Quality Control

Our o-Cresolphthalein is manufactured under strict quality management systems. Each batch undergoes comprehensive analytical testing to ensure it meets high-purity standards suitable for analytical and research applications. A detailed Certificate of Analysis (COA) is provided with every shipment, confirming identity, purity, and conformance to specifications.

Storage

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

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms
Assay (HPLC)	≥ 98.0%
Loss on Drying	≤ 0.5%
Residue on Ignition	≤ 0.1%
pH Transition Range	8.2 (colorless) to 9.8 (red-violet)
Suitability Test	Passes

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