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1.07241

Phenol red

pH indicator, ACS

Synonym(s):

Phenol red

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About This Item

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

SMILES string

[S]1(=O)(=O)OC(c4c1cccc4)(c3ccc(cc3)O)c2ccc(cc2)O

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

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

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pictograms

Exclamation mark
GHS07

signalword

Warning

hcodes

H315,H335

Hazard Classifications

Skin Irrit. 2 - STOT SE 3

target_organs

Respiratory system

Storage Class

11 - Combustible Solids

wgk

WGK 3

flash_point_f

Not applicable

flash_point_c

Not applicable

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

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