Solvent Yellow 124

Structural formula
General
Surname	Solvent Yellow 124
other names	N -Ethyl- N - (2- (1- (2-methylpropoxy) ethoxy) ethyl) -4 - [( E ) -phenyldiazenyl] aniline ( IUPAC )
Molecular formula	C 22 H 31 N 3 O 2
Brief description	yellow solid
External identifiers / databases
CAS number 34432-92-3 EC number 252-021-1 ECHA InfoCard 100.047.277 PubChem 118170 ChemSpider 105606 Wikidata Q60457
properties
Molar mass	369.50 g mol −1
safety instructions
GHS labeling of hazardous substances Caution H and P phrases H: 302-317-373-413 P: 260-280-363-273
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Solvent Yellow 124 is the color index name for a yellow azo dye that is used in the European Union as a marker for the detection of heating oil . Solvent Yellow 124 belongs to the application class of solvent dyes .

Use with heating oil

Positive test for light heating oil.

In order to make the improper use of (tax-privileged, i.e. comparatively cheap) heating oil as fuel more difficult, a label was introduced on April 1, 1976. In Germany, like in most EU member states, light heating oil was and is colored red. But there are also yellow or blue colors.

Since the staining can be removed relatively easily by a technically skilled person, furfural was added first, which can be detected with a simple test. Because furfural is too unstable and the test can only be carried out with relatively dangerous reagents, furfural has been replaced by Solvent Yellow 124 . In order to also be able to pursue violations internationally, since August 1, 2002, only Solvent Yellow 124 has been approved as a marking substance in the EU member states for uniform heating oil labeling . Solvent Yellow 124 itself hardly colors the heating oil, not even yellow. The red dye is also added for easy differentiation.

See also : Energy Tax Act: Use of heating oil for motor vehicles

proof

Hydrolysis of Solvent Yellow 124 in an acidic medium, resulting in a red dye.

Solvent Yellow 124 can be detected with an indicator reagent even at high dilution . The proportion of the fuel oil added must also be determined. Solvent Yellow 124 reacts in an acidic medium to form an intensely red, water-soluble dye that colors the lower aqueous phase red.

Individual evidence

1. ↑ Data sheet Solvent Yellow 124 from Sigma-Aldrich , accessed on May 18, 2017 ( PDF ).
2. ↑ ^{a b} Entry on N-Ethyl-N- [2- [1- (2-methylpropoxy) ethoxy] ethyl] -4- (phenylazo) aniline in the GESTIS substance database of the IFA , accessed on January 10, 2017(JavaScript required) .