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Key Documents

N8257

Sigma-Aldrich

α-Naphtholphthalein

>80% purity NaOH basis (titration), practical grade, powder

Synonym(s):

1-Naphtholphthalein; 3,3-Bis(4-hydroxynaphthalen-1-yl)isobenzofuran-1(3H)-one

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About This Item

Empirical Formula (Hill Notation):
C28H18O4
CAS Number:
Molecular Weight:
418.44
Beilstein:
97816
EC Number:
MDL number:
UNSPSC Code:
12171500
PubChem Substance ID:
NACRES:
NA.47

product name

α-Naphtholphthalein, practical grade

grade

practical grade

Quality Level

Assay

>80% NaOH basis (titration)

form

powder

technique(s)

titration: suitable

pH

7.3-8.7, colorless to blue-green

mp

238-240 °C (lit.)

solubility

ethanol: 50 mg/mL, clear, red-orange

application(s)

diagnostic assay manufacturing
hematology
histology

storage temp.

room temp

SMILES string

Oc1ccc(c2ccccc12)C3(OC(=O)c4ccccc34)c5ccc(O)c6ccccc56

InChI

1S/C28H18O4/c29-25-15-13-23(17-7-1-3-9-19(17)25)28(22-12-6-5-11-21(22)27(31)32-28)24-14-16-26(30)20-10-4-2-8-18(20)24/h1-16,29-30H

InChI key

HQHBAGKIEAOSNM-UHFFFAOYSA-N

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General description

α-Naphtholphthalein, a phthalein dye is a pH indicator between 7.3 (colorless) and 8.7 (greenish-blue). Applications include inks, markers, detecting viable cells, food storage, and many more.

Storage Class Code

11 - Combustible Solids

WGK

WGK 3

Flash Point(F)

Not applicable

Flash Point(C)

Not applicable

Personal Protective Equipment

dust mask type N95 (US), Eyeshields, Gloves

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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