Methyl Orange

Methyl Orange structural formula

CAS Number502-02-3
Molecular FormulaC14H15N3O3S
Molecular Weight305.350
InChI KeyIETWCRRCPURZOC-UHFFFAOYSA-N
LogP1.75
Synonyms
  • 4-{[4-(Dimethylamino)phenyl]diazenyl}benzene-1-sulfonic acid
  • Benzenesulfonic acid, 4-[2-[4-(dimethylamino)phenyl]diazenyl]-
  • 502-02-3
  • Benzenesulfonic acid, 4-[[4-(dimethylamino)phenyl]azo]-
  • Benzenesulfonic acid, 4-[2-[4-(dimethylamino)phenyl]diazenyl]-
  • Benzenesulfonic acid, p-[[p-(dimethylamino)phenyl]azo]-
  • 4-[2-[4-(Dimethylamino)phenyl]diazenyl]benzenesulfonic acid
  • 4-(Dimethylamino)-4'-sulfoazobenzene
  • Methyl orange (acid form)
  • p-[[p-(Dimethylamino)phenyl]azo]benzenesulfonic acid
  • Acide 4-[[4-(dimethylamino)phenyl]azo]benzenesulfonique
  • 4-[[4-(dimethylamino)phenyl]azo]benzenesulphonic acid
  • 4-[[4-(Dimethylamino)phenyl]azo]benzolsulfonsaure
  • acido 4-[[4-(dimetilamino)fenil]azo]bencenosulfonico
  • p-((p-(Dimethylamino)phenyl)azo)benzenesulfonic acid
  • EINECS 207-932-9
  • NSC 9595
  • 4'-Sulfo-N,N-dimethyl-4-aminoazobenzene
  • 4-(4-Dimethylaminophenylazo)benzenesulfonic acid
  • 4-(Dimethylamino)azobenzene-4'-sulfonic acid
  • 4-(4-Sulfophenylazo)-N,N-dimethylaniline

Applications:

Uv-Vis Spectrum of Methyl Orange

April 8, 2026

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If you are looking for optimized HPLC method to analyze Methyl Orange check our HPLC Applications library

For optimal results in HPLC analysis, it is recommended to measure absorbance at a wavelength that matches the absorption maximum of the compound(s) being analyzed. The UV spectrum shown can assist in selecting an appropriate wavelength for your analysis. Please note that certain mobile phases and buffers may block wavelengths below 230 nm, rendering absorbance measurement at these wavelengths ineffective. If detection below 230 nm is required, it is recommended to use acetonitrile and water as low UV-transparent mobile phases, with phosphoric acid and its salts, sulfuric acid, and TFA as buffers.
For some compounds, the UV-Vis Spectrum is affected by the pH of the mobile phase.  The compound was dissolved with water. This analysis was done with the mobile phase made of 20% acetonitrile and 80% water.

 

 

Application Analytes:
Methyl Orange
SIELC Technologies usually develops more than one method for each compound. Therefore, this particular method may not be the best available method from our portfolio for your specific application. Before you decide to implement this method in your research, please send us an email to research@sielc.com so we can ensure you get optimal results for your compound/s of interest.

HPLC Dye Separation on SHARC1 Column

July 10, 2013

 

Condition
Column Sharc 1, 3.2×100 mm, 3 µm, 100A
Mobile Phase MeCN/EtOH – 99/1%
Buffer H2SO4 – 0.5%
Flow Rate 1.5 ml/min
Detection UV, 500, 650 nm

 

Description
Class of Compounds
 Dye, Hydrophilic, Ionizable
Analyzing Compounds Methyl Red, Methyl Orange, Methylene Blue, Nile Blue A

 

Application Column

SHARC 1

The SHARC™ family of innovative columns represents the first commercially available columns primarily utilizing separation based on hydrogen bonding. SHARC stands for Specific Hydrogen-bond Adsorption Resolution Column. Hydrogen bonding involves an interaction or attraction between a bound hydrogen atom and molecules containing electronegative atoms, such as oxygen, nitrogen, and fluorine.

Select options
Application Analytes:
Methyl Orange
Methyl Red
Methylene Blue
Nile Blue A
Application Detection:
UV Detection
SIELC Technologies usually develops more than one method for each compound. Therefore, this particular method may not be the best available method from our portfolio for your specific application. Before you decide to implement this method in your research, please send us an email to research@sielc.com so we can ensure you get optimal results for your compound/s of interest.