The disclosure provides dyes for marking hydrocarbon compositions. More particularly, the disclosure relates to non-mutagenic dyes for marking hydrocarbon compositions.

A method of marking a hydrocarbon fuel, the method comprising adding to said hydrocarbon fuel a tracer compound for marking the hydrocarbon fuel, the tracer compound being a substituted fluorene having a structure of Formula (I): wherein R1 and R2 are the same or different and selected from hydrogen, straight chain, branched or cyclic alkyl groups, phenyl or substituted phenyl groups, benzyl or substituted benzyl groups, or R1 and R2 form a single substituent linked intramolecularly to each other, or R1 and R2 are ether groups excluding acetal groups, wherein R3 and R4 are the same or different and selected from hydrogen, straight chain, branched or cyclic alkyl groups, phenyl or substituted phenyl groups, benzyl or substituted benzyl groups, and wherein at least one of R1, R2, R3, and R4 is not hydrogen.

##STR00001##

The present disclosure provides compositions, methods, and systems for identifying marked hydrocarbon fluids. These compositions, methods, and systems utilize a gas chromatography marker including a non-pyrrolidinone nitrogen-containing compound. The methods and systems can identify the presence or absence of the gas chromatography marker and/or the non-pyrrolidinone nitrogen-containing compound. The compositions, methods, and systems can optionally utilize a spectroscopic marker.

The present invention provides a method for determining the authenticity of a petroleum hydrocarbon allegedly comprising at least one specific chemical marker, as well as a method for determining adulteration of a petroleum hydrocarbon marked with at least one specific chemical marker. The methods claimed and described herein rely upon the use of specific chemical markers in combination with laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with ion mobility spectrometry or with mass spectrometry.

A compound of formula (I): ##STR00001## wherein p is at least 1, n is at least 1 and less than or equal to p; Ar is a polycyclic aromatic moiety, R.sup.1 is hydrogen or an optionally substituted hydrocarbyl group and each of R.sup.2, R.sup.3 and R.sup.4 is independently an optionally substituted hydrocarbyl group, provided that at least one of R.sup.2, R.sup.3 and R.sup.4 has at least 6 carbon atoms.

A Liquid, comprising an hydrophobic flavonoid derivative electrochemically non-active, that is capable of restoring its electrochemical activity, the concentration of the flavonoid derivative being 10 ppm by weight or less, and an organic substance in an amount of 90% by weight or more.

The invention provides a composition which comprises an apolar medium and a tracer compound, which tracer compound comprises a hydrophobic group and an oligonucleotide. Various uses of the tracer compound are also described.

A method for marking a petroleum hydrocarbon or a liquid biologically derived fuel; said method comprising adding to said petroleum hydrocarbon or liquid biologically derived fuel at least one compound that is a R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, R.sup.9 and R.sup.10-substituted diaryl ether, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.7, R.sup.8, R.sup.9 and R.sup.10 independently are hydrogen, hydrocarbyl or hydrocarbyloxy; wherein each compound having formula (I) is present at a level from 0.01 ppm to 20 ppm.

The present disclosure provides methods for identifying a hydrocarbon fuel, such as the presence and/or amounts of marker compounds having a fluorescence intensity and, through correlation, the presence and/or amounts of additive package(s) within the hydrocarbon fuel.

A fuel additive for fuel formulations comprising calcium sulfonates in an amount effective to limit or eliminate valve seat recession in engines utilizing such fuel formulations. The fuel additive may also include a detergent, particularly in an amount to enhance the VSR limiting effect of the calcium sulfonates. Also included are fuel formulations containing calcium sulfonates in a concentration effective to limit vale seat recession in engines utilizing the fuel formulations. Methods for treating VSR in piston engines are also provided.