1.07241

Phenol red

pH indicator, ACS

• Synonym(s): Phenol red
• Linear Formula: (C₆H₄OH)₂C₇H₄SO₃
• CAS Number: 143-74-8
• Molecular Weight: 354.38
• MDL number: MFCD00003552
• UNSPSC Code: 12171502
• EC Index Number: 205-609-7
• NACRES: NA.21

Properties

• product name: Phenol red, indicator ACS
• grade: ACS reagent
• Quality Level: 200
• form: solid
• loss: ≤1% loss on drying, 110°C
• visual transition interval: 1.2-3.0, brown-orange to yellow(1st transition range); 6.5-8.0, brownish-yellow to red-violet(2nd transition range)
• mp: >300 °C
• bulk density: 200‑300 kg/m³
• storage temp.: 2-30°C
• InChI: 1S/C19H14O5S/c20-15-9-5-13(6-10-15)19(14-7-11-16(21)12-8-14)17-3-1-2-4-18(17)25(22,23)24-19/h1-12,20-21H
• InChI key: BELBBZDIHDAJOR-UHFFFAOYSA-N

Description

General description

Phenol red (phenolsulfonphthalein, PH R) belongs to the class of triphenylmethane dyes. It is a waterͰsoluble anionic dye, mostly used as a pH indicator in cell biology laboratories. Also, in different protocols, it is used to detect H₂O₂(Hydrogen peroxide).

Application

Phenol red can be used as a:

• Dye in the preparation of phenol red/n-Si photodiode [phenol red/n-type silicon wafer] by spin coating technique. The device is appropriate for photo-detection applications.
• Color-changing dye in the design of fiber optic pH sensor because as the acidity increases, the dye′s absorption properties shift from the green to the blue section of the spectrum.
• Indicator in the determination of freshwater pH.

Features and Benefits

Phenol red is used to detect pH changes in cell culture,

• pH is 6.4 or below yellow color
• pH is 8.2 or above red color.

Analysis Note

Appearance of solution: passes test
1st transition range: pH 1.2 - pH 3.0brownish orange - yellow
2nd transition range: pH 6.5 - pH 8.0brownish yellow - red violet
Loss on drying (110 °C): ≤ 1
Transition range (according to ACS): passes test
ACS conforms

Safety Information

• pictograms: GHS07
• signalword: Warning
• hcodes: H315 - H335
• pcodes: P261 - P264 - P271 - P280 - P302 + P352 - P304 + P340 + P312
• Hazard Classifications: Skin Irrit. 2 - STOT SE 3
• target_organs: Respiratory system
• Storage Class: 11 - Combustible Solids
• wgk_germany: WGK 3
• flash_point_f: Not applicable
• flash_point_c: Not applicable