Skip to Content
Merck
All Photos(1)

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

Sign Into View Organizational & Contract Pricing


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

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

Looking for similar products? Visit Product Comparison Guide

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’.

Already Own This Product?

Find documentation for the products that you have recently purchased in the Document Library.

Visit the Document Library

Customers Also Viewed

Slide 1 of 1

1 of 1

Jeenat Aslam et al.
ACS omega, 4(26), 22152-22160 (2020-01-01)
Binding effect and interaction of N,N'-dialkyl cystine based gemini surfactant (GS); 2(C12Cys) with human serum albumin (HSA) were systematically investigated by the techniques such as surface tension measurement, UV-visible spectroscopy, fluorescence spectroscopy, circular dichroism (CD) spectroscopy, and molecular docking studies.
I M Pérez de Vargas-Sansalvador et al.
Analytica chimica acta, 655(1-2), 66-74 (2009-11-21)
A study of different strategies to prepare phosphorescence-based sensors for gaseous CO(2) determination has been performed. It includes the characterization of different configurations tested, a discussion of the results obtained and possibilities for the future. The optical sensor for gaseous

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service