Anisidine value
Anisidine value (AV) is a measure of the aldehyde levels in an oil or fat, in particular those that are unsaturated (and principally the 2–alkenals). To determine AV, a solution of the oil or fat in iso-octane is reacted with p-anisidine in glacial acetic acid to form yellowish reaction proucts. The AV is then determined from the absorbance measured at 350 nm, both before and after reaction.
Chemical Properties
Anisidine exists as ortho-, meta-, and paraisomers. They have characteristic amine (fishy) odors. releases toxic nitrogen oxides when heated to decomposition (Sax and Lewis, 1987).
Physical properties
Yellow to light brown powder, leaflets, solid or crystals with a characteristic amine or ammonialike odor. soluble in ethanol and ether, slightly soluble in water.
Uses
p-Anisidine is used mostly for producing dyes, and some smaller quantities are employed in making pharmaceuticals and liquid crystals.
Application
p-Anisidine is used as a reagent to indicate the secondary stage of the oxidation, it is one of the three possible isomers of the Anisidine or methoxyaniline. The other two isomers are o-Anisidine (2-methoxyaniline) and m-Anisidine (3-methoxyaniline).
The p-anisidine is widely used as an intermediate in the production of numerous azo and triphenylmethane dyes, and pigments. It is also used in the production of pharmaceuticals including the guaiacol expectorant, as an antioxidant for polymercaptan resins, and as a corrosion inhibitor for steel. Apart from the beneficial use of p-anisidine, it is toxic for human beings. The acute exposure may cause skin irritation, whereas the chronic exposure may cause headaches, vertigo, and blood complications like sulfhemoglobin, and methemoglobin. The oral exposure to anisidine hydrochloride resulted in cancer of the urinary bladder in male and female rats.
https://www.longdom.org/open-access/physicochemical-and-spectroscopic-characterization-of-biofield-energytreated-panisidine-paco-1000102.pdf
Definition
ChEBI: P-anisidine is a substituted aniline that is aniline in which the hydrogen para to the amino group has been replaced by a methoxy group. It is used as a reagent for the detection of oxidation products such as aldehydes and ketones in fats and oils. It has a role as a reagent and a genotoxin. It is a member of methoxybenzenes, a substituted aniline and a primary amino compound.
Preparation
p-Anisidine is an important intermediate for synthesis of dye, medicine and perfume. Traditional preparation of p-Anisidine uses iron powder or sodium sulfide as reductant, which produces a large amount of waste and results in serious environment pollution problem. Liquid phase catalytic hydrogenation is not only an environmentally benign technique but also of high yield.
Synthesis of p-Anisidine by Hydrogenation with Raney-RuNiC as Catalyst
General Description
P-anisidine appears as brown crystals or dark brown solid. Characteristic amine odor. (NTP, 1992)
Air & Water Reactions
Insoluble in water.
Reactivity Profile
p-Anisidine may be sensitive to heat, light and moisture. Reacts with acids, acid chlorides, acid anhydrides, chloroformates and strong oxidizing agents. Incompatible with alkaline materials. Incompatible with aldehydes, ketones and nitrates.
Hazard
Strong irritant. Toxic when absorbed
through the skin. Questionable carcinogen.
Fire Hazard
p-Anisidine is flammable.
Safety Profile
Moderately toxic by
several routes. A mild sensitizer. May cause
a contact dermatitis. Mutation data reported.
Questionable carcinogen. See also
ANILINE. When heated to decomposition
it emits toxic fumes of Nox
Potential Exposure
Anisidines are used in the manufacture
of azo dyes; pharmaceuticals; textile-processing chemicals
Incompatibilities: Incompatible with oxidizers (chlorates,
nitrates, peroxides, permanganates, perchlorates, chlorine,bromine, fluorine, etc.); contact may cause fires or explosions.
Keep away from alkaline materials, strong bases,
strong acids, oxoacids, epoxides. Attacks some coatings
and some forms of plastic and rubber.
Carcinogenicity
Available
data were inadequate to evaluate the carcinogenicity
of p-anisidine.
Shipping
UN2431 Anisidines, Hazard Class: 6.1; Labels:
6.1-Poisonous materials
Purification Methods
Crystallise p-anisidine from H2O or aqueous EtOH. Dry it in a vacuum oven at 35o for 6hours and store it in a dry box. [More et al. J Am Chem Soc 108 2257 1986.] Purify it also by vacuum sublimation [Guarr et al. J Am Chem Soc 107 5104 1985]. [Beilstein 13 IV 1015.]
Waste Disposal
Dissolve in combustible solvent
(alcohols, benzene, etc.) and spray solution into furnace
equipped with afterburner and scrubber, or burn spill
residue on sand and soda ash absorbent in a furnace.
