Solvent Yellow 124

Names
IUPAC name N-Ethyl-N-[2-[1-(2-methylpropoxy)ethoxy]ethyl]-4-phenyldiazenylaniline
Other names SY124; Sudan 455; Somalia Yellow; T10 Yellow LBN; C.I. 111155
Identifiers
CAS Number	34432-92-3 Y
3D model (JSmol)	Interactive image
ChemSpider	105606 Y
ECHA InfoCard	100.047.277
PubChem CID	118170
UNII	E880XYT70P Y
CompTox Dashboard (EPA)	DTXSID60865718
InChI InChI=1S/C22H31N3O2/c1-5-25(15-16-26-19(4)27-17-18(2)3)22-13-11-21(12-14-22)24-23-20-9-7-6-8-10-20/h6-14,18-19H,5,15-17H2,1-4H3/b24-23+ Y Key: BATVZJPOLFSGTD-WCWDXBQESA-N Y InChI=1/C22H31N3O2/c1-5-25(15-16-26-19(4)27-17-18(2)3)22-13-11-21(12-14-22)24-23-20-9-7-6-8-10-20/h6-14,18-19H,5,15-17H2,1-4H3/b24-23+ Key: BATVZJPOLFSGTD-WCWDXBQEBJ
SMILES N(=N/c1ccc(N(CCOC(OCC(C)C)C)CC)cc1)\c2ccccc2
Properties
Chemical formula	C22H31N3O2
Molar mass	369.509 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

Solvent Yellow 124 is a yellow azo dye used in European Union as a fuel dye. It is a marker used since August 2002 to distinguish diesel fuel intended for heating from a higher-taxed motor diesel fuel. It is added to fuels not intended for motor vehicles in amounts of 6 mg/L or 7 mg/kg under the name Euromarker.^[1]

Euromarker

Solvent Yellow 124 is a dye with structure similar to Solvent Yellow 56. This dye can be easily hydrolyzed with acids, splitting off the acetal group responsible for its solubility in nonpolar solvents, and yielding a water-soluble form which is easy to extract to water. Like a similar methyl orange dye, it changes color to red in acidic pH. It can be easily detected in the fuel at levels as low as 0.3 ppm by extraction to a diluted hydrochloric acid, allowing detection of the red diesel added into motor diesel in amounts as low as 2-3%.

Solvent Yellow 124 is intended to be difficult to remove from the fuel in an economical way. The Customs, familiar with various tricks including dual fuel systems with hidden fuel tanks, will take samples from the fuel lines to the engine itself if such equipment is suspected in the car.

As the amount of Solvent Yellow 124 added to the fuel is known, by measuring its content in the fuel it is possible to calculate how much of the low-taxed fuel was added to the legal one.

Concerns

The UK government expressed concerns about the possibility of "laundering" the dye out of "illicit" fuel, hampering the detection.^[2] Denmark expressed concerns about the dye's toxicity.

Euromarker is intended to be replaced later by newer technology markers, such as biological markers or fuel markers with non-destructive analytical methods. These are all special chemicals tailored for the individual products, and perhaps even for individual refineries, allowing the identification of the source of the material by its content of the molecular markers.

In 2014, a new fuel marker more resistant to removal was announced for the United Kingdom.^[3]