Description
Metanil yellow is a yellow monoazo dye. This coloring
agent is used in leather and wood stains, and was also
employed as a food dye in India.
Chemical Properties
orange powder
Uses
dye used in leather; as indicator (pH) in laboratories
Uses
Metanil Yellow is used as indicator. Metanil yellow is useful in spectrophotometric methods to determine the presence of trace amounts of nitrates and nitrites in solution. The method utilizes the fact that potassium bromate can catalyze the discoloring of Metanil yellow which can then be analyzed by spectrophotometry.
Uses
As indicator in 0.1% solution, of which 2 drops are required for 10 ml liquid. pH: 1.2 red to 2.3 yellow.
Definition
ChEBI: An organic sodium salt having 3-[(4-anilinophenyl)diazenyl]benzene-1-sulfonate as the counterion. Used in one variant of Masson's trichrome to stain collagen yellow in contrast to the red muscle, but is not in common used.
General Description
Metanil yellow is an azo dye, which is used as a counterstain in PAS (periodic acid-Schiff) or iron-hematoxylin stained sections to increase contrast. At pH 1.2, metanil yellow is red in color, whereas in pH 2.3, it is yellow in color.
Flammability and Explosibility
Not classified
Contact allergens
Metanil yellow is a yellow monoazoic dye. This color ing agent is used in leather and wood stains, and is also employed as a food dye in India.
Biochem/physiol Actions
Metanil yellow is an azo dye. It is used as a counterstain in PAS (periodic acid-Schiff)/iron-hematoxylin stained sections to increase contrast. Metanil yellow changes its color from red at pH 1.2 to yellow at pH 2.3.
Safety Profile
Moderately toxic by
intraperitoneal route. Experimental
reproductive effects. Human mutation data
reported. When heated to decomposition it
emits toxic fumes of SOx, NOx, and NazO.
See also AROMATIC AMINES and
SULFONATES.
Purification Methods
It can be salted out from water three times with sodium acetate, then repeatedly extracted with EtOH [McGrew & Schneider J Am Chem Soc 72 2547 1950]. [Beilstein 16 II 168.]
Properties and Applications
|
Standard
|
Light Fastness
|
Soaping
|
Persperation Fastness
|
Oxygen bleaching
|
Fastness to seawater
|
|
Fading
|
Stain
|
Fading
|
Stain
|
Fading
|
Stain
|
|
ISO
|
3
|
2
|
|
2-3
|
|
|
|
|
|
AATCC
|
3
|
1
|
|
4
|
|
|
5
|
1
|
