Description

Phenolphthalein is a synthetic organic compound belonging to the phthalein dye family, widely recognized as a classic acid-base indicator. Its primary value lies in its distinct and reversible color change from colorless in acidic solutions to a vibrant pink/fuchsia in basic solutions, making it an indispensable tool for visual endpoint detection. This compound is essential for laboratories, educational institutions, and industrial quality control processes requiring precise pH determination and titration analysis.

Application

• Acid-Base Titration Indicator: The most common application, used to visually determine the equivalence point in titrations of strong acids with strong bases.
• Laboratory Reagent & Educational Demonstrations: A fundamental chemical for teaching chemistry principles in schools and universities.
• Manufacturing of Dyes and Pigments: Serves as a key intermediate in the synthesis of certain triarylmethane dyes.
• Medical and Biological Staining (Historical): Previously used in certain histological stains; modern use is limited and subject to strict regulations.
• Chemical Synthesis Intermediate: Used in organic synthesis for producing more complex molecules.
• Testing Cement Carbonation: Applied in construction and civil engineering to assess the depth of carbonation in concrete structures.
• Forensic Analysis: Employed in some presumptive tests, such as the Kastle-Meyer test for the possible presence of blood.

Basic Information

Product Name	Phenolphthalein
CAS No.	77-09-8
Molecular Formula	C20H14O4
Molecular Weight	318.33 g/mol
Synonyms	3,3-Bis(4-hydroxyphenyl)-1(3H)-isobenzofuranone; 3,3-Bis(4-hydroxyphenyl)phthalide; Phenolphthalein Indicator; Dihydroxyphthalophenone; Phthalein; Laxogen; Purgyl; Agoral; Espotabs; Phenolax; Prulet; 77-09-8
EINECS	201-004-7

Quality Control

Our Phenolphthalein is manufactured under a strict quality management system. Each batch undergoes rigorous analytical testing to ensure it meets high-purity standards suitable for laboratory and industrial use. Key parameters such as identity, assay, melting point, and solubility are verified. A comprehensive Certificate of Analysis (COA) detailing all test results is provided with every shipment to guarantee traceability and compliance.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at room temperature (15-25°C). Keep away from incompatible materials such as strong oxidizing agents and strong bases.

Specification

Item	Specification
Appearance	White to faintly yellowish white, crystalline powder
Identification (IR)	Conforms
Melting Point	258°C - 263°C
Assay (HPLC)	≥ 98.0%
Loss on Drying	≤ 0.5%
Sulfated Ash	≤ 0.1%
Solubility (in Ethanol)	Clear, colorless solution
pH Transition Range	8.2 (colorless) to 10.0 (pink/fuchsia)

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