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105945

Sigma-Aldrich

Phenolphthalein

ACS reagent

Synonym(s):
3,3-Bis(4-hydroxyphenyl)-1(3H)-isobenzofuranone
Empirical Formula (Hill Notation):
C20H14O4
CAS Number:
Molecular Weight:
318.32
Colour Index Number:
764
Beilstein:
284423
EC Number:
MDL number:
PubChem Substance ID:
NACRES:
NA.47

grade

ACS reagent

Quality Level

form

powder

technique(s)

titration: suitable

visual transition interval

8.0-10, colorless to red

mp

261-263 °C (lit.)

solubility

acetone: soluble

density

1.27 g/cm3 at 32 °C

λmax

374 nm (2nd)
552 nm

application(s)

diagnostic assay manufacturing
hematology
histology

storage temp.

room temp

SMILES string

Oc1ccc(cc1)C2(OC(=O)c3ccccc23)c4ccc(O)cc4

InChI

1S/C20H14O4/c21-15-9-5-13(6-10-15)20(14-7-11-16(22)12-8-14)18-4-2-1-3-17(18)19(23)24-20/h1-12,21-22H

InChI key

KJFMBFZCATUALV-UHFFFAOYSA-N

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This Item
319236114529P3532
Phenolphthalein ACS reagent

Sigma-Aldrich

105945

Phenolphthalein

Phenol Red ACS reagent

Sigma-Aldrich

114529

Phenol Red

Phenol Red powder, BioReagent, suitable for cell culture

Sigma-Aldrich

P3532

Phenol Red

form

powder

form

liquid

form

powder

form

powder

technique(s)

titration: suitable

technique(s)

-

technique(s)

titration: suitable

technique(s)

cell culture | mammalian: suitable

mp

261-263 °C (lit.)

mp

-35 °C

mp

-

mp

>300 °C

solubility

acetone: soluble

solubility

-

solubility

-

solubility

1 M NaOH: 1 mg/mL

density

1.27 g/cm3 at 32 °C

density

0.918 g/mL at 25 °C

density

-

density

-

General description

Phenolphthalein is an indicator for acid-base titration reactions. It changes from colorless to violet-red between pH 8.3-9.8, it is red in extremely acidic solutions, and colorless in extremely alkaline solutions.

It is present as a nonionic, lipophilic lactone in aqueous neutral solutions. It exists as a hydrophilic dianion in alkaline solutions.

Application

Phenolphthalein has been commonly used as an indicator in the fields of biology and medicine. Its applications include:

  • the development of novel technique to monitor the vacuum freeze-drying process
  • the determination of the depth of carbonation in concrete
  • the utilization of liquid marbles to sense gaseous environmental components
  • the estimation of total acidity in vinegar
  • the assessment of sodium hydroxide penetration into potatoes following chemical peeling
  • as a model organic compound in the evaluation of the capture efficiency of various cyclodextrin constructs such as nanofiber-CD

Biochem/physiol Actions

Phenolphthalein is colorless in acidic solutions and turns pink in basic solutions.

Principle

Phenolphthalein undergoes structural modification when there is a change in pH or in the structural state of water. It is a nonionic, lipophilic colorless lactone in aqueous neutral solutions and a hydrophilic dianion in alkaline solutions.

Pictograms

Exclamation markHealth hazard

Signal Word

Danger

Hazard Classifications

Carc. 1B - Muta. 2 - Repr. 2 - Skin Irrit. 2

Storage Class Code

6.1C - Combustible, acute toxic Cat.3 / toxic compounds or compounds which causing chronic effects

WGK

WGK 3

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

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Electrospinning has been used to successfully create polystyrene (PS) nanofibers containing either of three different types of cyclodextrin (CD); α-CD, β-CD, and γ-CD. These three CDs are chosen because they have different sized cavities that potentially allow for selective inclusion
Ping Chen et al.
ACS nano, 5(7), 5928-5935 (2011-06-15)
In this paper, we report the fabrication of carbonaceous nanofiber (CNF) membranes functionalized by beta-cyclodextrins (CNF-β-CD membrane) and their application for molecular filtration. The chemically synthesized carbonaceous nanofibers were first functionalized by β-CD, and the free-standing CNF membrane can be
Nantao Hu et al.
Journal of nanoscience and nanotechnology, 12(1), 99-104 (2012-04-25)
Recently, much work has focused on the exfoliation of graphene through a combination of oxidation and sonication procedures, followed by reduction through chemical methods. We demonstrated that the individual graphene oxide sheets can be readily reduced by using phenolphthalin as
Wasin Wongwilai et al.
Talanta, 81(3), 1137-1141 (2010-03-20)
A modification of a webcam camera for use as a small and low cost detector was demonstrated with a simple lab-on-chip reactor. Real time continuous monitoring of the reaction zone could be done. Acid-base neutralization with phenolphthalein indicator was used

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