Methyl Red

Methyl Red Basic information
Description
Product Name:Methyl Red
Synonyms:CI NO 13020;BROMOCRESOL GREEN-METHYL RED;BROMOCRESOL GREEN-METHYL RED ETHANOL;BROMOCRESOL GREEN/METHYL RED, MIXED INDICATOR;BROMOCRESOL GREEN/METHYL RED, MIX INDICATOR FOR ALKALINITY;2-(4-Dimethylaminophenylazo)benzoic acid, 4-Dimethylaminoazobenzene-2μ-carboxylic acid, Acid Red2;METHYL RED;METHYL RED INDICATOR
CAS:493-52-7
MF:C15H15N3O2
MW:269.3
EINECS:207-776-1
Product Categories:BTitration;Indicator Solutions;Indicators;Stains and Dyes;Stains&Dyes, A to;Titration;Organics;Analytical Chemistry;Indicator (pH);pH Indicators;Biochemical Reagents for Identification;Identification Tests&Reagents;Microbiology;Azo
Mol File:493-52-7.mol
Methyl Red Structure
Methyl Red Chemical Properties
Melting point 179-182 °C (lit.)
Boiling point 412.44°C (rough estimate)
density 0.839 g/mL at 25 °C
vapor density 9.3 (vs air)
refractive index 1.5930 (estimate)
Fp 11 °C
storage temp. Store at +5°C to +30°C.
solubility ethanol: soluble1mg/mL
Colour Index 13020
form Solid
pka4.95(at 25℃)
color Reddish-violet
OdorOdorless
PH Range4.4(red)-6.3(yellow)
Water Solubility Practically insoluble in water. Soluble in alcohol, acetic acidSoluble in ethanol. Insoluble in water.
λmax410nm, 530nm, 427nm, 519nm
Merck 14,6119
BRN 750102
Stability:Stable. Incompatible with strong oxidizing agents.
Major ApplicationWaveguides, LED sensors, photoresists, liquid crystals, sol-gel matrix, optical sensors, paints, toys, detection of thiols, food freshness sensors, dental product, saliva sampling method, detecting lactic acid, carbohydrates
InChIKeyCEQFOVLGLXCDCX-MSUUIHNZSA-N
CAS DataBase Reference493-52-7
IARC3 (Vol. 8, Sup 7) 1987
NIST Chemistry ReferenceBenzoic acid, 2-[[4-(dimethylamino)phenyl]azo]-(493-52-7)
EPA Substance Registry SystemMethyl red (493-52-7)
Safety Information
Hazard Codes Xn,T,F,Xi,C,N
Risk Statements 10-20/21/22-68/20/21/22-68-36/38-23/25-11-36/37/38-34-51/53-39/23/24/25-23/24/25
Safety Statements 36/37-24/25-22-45-33-24-16-7-36-26-36/37/39-61
RIDADR UN 1170 3/PG 2
WGK Germany 1
RTECS DG8960000
TSCA Yes
HazardClass 3
PackingGroup II
HS Code 29270000
Hazardous Substances Data493-52-7(Hazardous Substances Data)
MSDS Information
ProviderLanguage
Acid Red 2 English
ACROS English
SigmaAldrich English
ALFA English
Methyl Red Usage And Synthesis
DescriptionMethyl red is a commonly used indicator for acid-base titrations. This chemical is usually yellow but turns red below pH 4.0. Bacteria exhibiting mixed acids fermentation will accumulate acids in the medium, resulting in a color change. Approximately five drops of methyl red reagent are added to an overnight culture grown in MRVP broth to determine the test result.
Different bacteria convert dextrose and glucose to pyruvate using different metabolic pathways. Some of these pathways produce unstable acidic products which quickly convert to neutral compounds. Some organisms use the butylene glycol pathway, which produces neutral end products, including acetoin and 2,3-butanediol. Other organisms use the mixed acid pathway, which produces acidic end products such as lactic, acetic, and formic acid. These acidic end products are stable and will remain acidic.
The Methyl Red test involves adding the pH indicator methyl red to an inoculated tube of MR-VP broth. If the organism uses the mixed acid fermentation pathway and produces stable acidic end-products, the acids will overcome the buffers in the medium and produce an acidic environment in the medium. When methyl red is added, if acidic end products are present, the methyl red will stay red.

Chemical Propertiesdark red crystalline powder
UsesUsed as pH indicator.
UsesAs indicator in 0.1% alcoholic solution; pH: 4.4 red, 6.2 yellow. Used for titrating NH3, weak organic bases, e.g., alkaloids; not suitable for organic acids, except oxalic and picric acid. Methyl red is easily reduced, thereby losing its color, and readings should be made promptly. It is gradually being replaced by sulfonphthalein indicators, such as bromcresol green, which are more stable and exhibit a sharper change in color.
UsespH indicator in pH range 4.2 - 6.3Methyl red is used as a pH indicator. It is red in pH less than 4.4 and yellow in pH over 6.2. It is used to study its degradation using Fenton's reagent. In microbiology, it is used to identify bacteria producing stable acids by mechanisms of mixed acid fermentation of glucose.
DefinitionChEBI: An azo dye consisting of benzoic acid substituted at position 2 by a 4-[(dimethylamino)phenyl]diazenyl group.
DefinitionAn acid–base indicator that is red in solutions below a pH of 4.2 and yellow above a pH of 6.3. It is often used for the same types of titration as methyl orange but the transition range of methyl red is nearer neutral (pH7) than that of methyl orange. The two molecules are structurally similar.
Definitionmethyl red: An organic dye similarin structure and use to methyl orange.It changes from red below pH4.4 to yellow above pH 6.0 (at 25°C).
Preparation2-Aminobenzoic acid?diazo, and N,N-dimethylaniline coupling.
General DescriptionMethyl red solution is an azo dye which turns to red when pH is below 4.4 (yellow pH < 6.2, orange pH 4.4-6.2). Some bacteria utilize glucose to form large amounts of acid with the result that the pH value of the medium falls distinct. Other species produce no or less free acid. This difference can be visualized by using methyl red. This test is used to differentiate enteric bacteria.
HazardQuestionable carcinogen.
Biochem/physiol ActionsMethyl Red is a maroon red crystal azo dye. Methyl Red is a pH indicator and changes color at a pH of 5.5. Methyl Red is widely used in saliva sampling method. In addition, it is also employed in carbohydrate and lactic acid detection. Methyl Red has been effectively used for intrageneric differentiation of Enterobacteriaceae.
Safety ProfileQuestionable carcinogen with experimental tumorigenic data. Mutation data reported. When heated to decomposition it emits toxic fumes of NOx.
Properties and Applicationsmoderate soluble in ethanol, insoluble in water. Alcohol solution to join hydrochloric acid for purple; Add sodium hydroxide to dim yellow.
Purification MethodsThe acid is extracted with boiling toluene using a Soxhlet apparatus. The crystals which separate on slow cooling to room temperature are filtered off, washed with a little toluene and recrystallised from glacial acetic acid, *benzene or toluene followed by pyridine/water. Alternatively, dissolve it in aqueous 5% NaHCO3 solution, and precipitate it from a hot solution by dropwise addition of aqueous HCl. Repeat this until the extinction coefficients do not increase. [Beilstein 16 IV 504.]
Methylparaben 4-AMINOAZOBENZENE Chlorodimethylphenylsilane Methyl Ethyl 2-(Chlorosulfonyl)acetate AQUANTRAAL Ascoric Acid Parathion-methyl 4-Dimethylaminobenzoic acid ACID RED 88 Red 2 SULFORHODAMINE B 2-Dimethylaminoethanol Kresoxim-methyl METHYL RED, WATER SOLUBLE Methyl acrylate Anthranilic acid Methyl acetate

Email:[email protected] [email protected]
Copyright © 2024 Mywellwork.com All rights reserved.