Phenolphthalein CAS 77-09-8

Chemical Name: Phenolphthalein

CAS No.: 77-09-8

Molecular Fomula: C20H14O4

Chemical Structure:Phenolphthalein Structure

Molecular weight: 318.32

Appearance: A white powder, practically insoluble in water, soluble in alcohol.

Assay: 98.0%-101.0%(C2OHi4O4)


Phenolphthalein CAS 77-09-8

Item Specifications
Characteristics A white or almost white powder, practically insoluble in water, soluble in alcohol.
Melting Point It melts at about 260℃
Identification A:Positive B:Positive
Appearance of solution The solution is clear and not more intensely coloured than reference solution Y7
Related substances Less than 0.5%
Heavy metals Not more than0.001%
Acidity or alkalinity Complies
Chlorides Not more than 0.01%
Sulphates Not more than 0.02%
Loss on drying Not more than 0.5%
Sulphated ash Not more than 0.1%
Assay 98.0%-101.0%(C2OHi4O4)
Microorganism TPC<1000cfu/g
Y and M <100cfu/g
E-coli – absent
Staphylococcus Aureus-Absent
Pseudomonas Aeruginosa-Absent
Albicans Saccharomyces-Absent


Phenolphthalein Usage

1. Phenolphthalein is a weak organic acid. It is white or slightly yellowish fine crystals at room temperature. It is odorless and tasteless. It is hardly soluble in water but easily soluble in alcohol (ethanol) and ether. Dissolved in alcohol solution to make acid-base indicator, it is colorless in acid solution, red in lye or alkali metal carbonate solution, but if it is in concentrated alkali solution, it will generate colorless trimetal The salt, the red faded. In view of this characteristic, it is often used as an indicator of acid-base titration in laboratories. The color range of PH value is 8.2~10.0, from colorless to red. When the phenolphthalein reagent is dripped into water or a neutral, acidic aqueous solution, white turbidity will appear. This is because alcohol is easily soluble in water and the phenolphthalein, which is hardly soluble in water, precipitates out in the reagent.

2. Pharmaceutical Ingredients: Phenolphthalein is used as a pharmaceutical light laxative for habitual and persistent constipation. It is available in tablets, suppositories and other dosage forms, mainly in the colon, through the decomposition of the body to form soluble sodium salts, stimulate the nerve plexus in the intestinal wall, so that peristalsis increases and promote defecation.
3. Organic synthesis: Phenolphthalein is also used in the synthesis of plastics, especially the synthesis of diazanaphthone polyarylether ketone polyarylether ketone polymers. These polymers have good heat resistance, water resistance, chemical resistance, heat aging resistance and processing and shaping, made of fibres, coatings and composites are widely used in electrical and electronic appliances, machinery and equipment, transportation, aerospace, atomic energy engineering and military and other fields.

4. Chemical analysis: Phenolphthalein can be used as an endocrinator for the colocal determination of key acidity and detection of magnesium ions. Phenolphthalein as an endocrinator can indicate the concentration of Chinese acid. In the detection of magnesium ions, phenolphthalein can indicate the presence and concentration of magnesium ions.

5. Biochemical trails: Phenolphthalein may be used as an identifier for some biochemical tests to detect the presence or absence of traits, e.g. detection of the presence of enzyme reactions and metabolic activity.

6. Pharmaceuticals and pigments: Phenolphthalein can be prepared as a synthetic compound for some organopharmaceuticals and pigments. It can be used as a preparation to give different colours to rolls and other materials.

PhenolphthaleinPackaging and Shipping

Fiber Drum,25kg


Phenolphthalein Storage

Store in a cool, dry place.


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