OA20000A

OA20000A - Method for marking a petroleum hydrocarbon.

Info

Publication number: OA20000A
Application number: OA1202000351
Authority: OA
Inventors: Thomas Tiller; Martin ZÜHKE; Daniel RIEBE; Toralf Beitz; Ünige LASKAY; Juan Lopez Gejo
Original assignee: Sicpa Holding Sa
Priority date: 2019-12-03
Filing date: 2020-09-17
Publication date: 2021-08-31

Abstract

The present invention relates to a method for making a petroleum hydrocarbon to prevent counterfeiting of said hydrocarbon by adding to and uniformly mixing with said petroleum a chemical marker of general formula (I) wherein the residues A and B are independently of each other selected from the group consisting of R7 , NRaRb and NRcRd , with the proviso that at least one of the residue A and B represents NRaRb ; the residues R1 -R6 are independently of each other selected from the group consisting hydrogen, C1-C6-alkyl and NReRf ; the residue R7 is selected from the group consisting of hydrogen and C1-C6-alkyl or alternatively, the substituents Ra and Rb are independently of each other selected from C1-C6-alkyl or alternatively, substituents Ra and Rb taken together from a residue -(CH2)n-, wherein n is an integer from 2 to 5; the substituents Rc and Rd are independently of each other selected from C1-C6alkyl, or alternatively the substituents Rc and Rd taken together from a residue -(CH2)m-, wherein m is an integer from 2 to 5 and the substituents Re and Rf are independently of each other selected from C1-C6-alkyl or alternatively, the substituents Re and Rf taken together from a residue -(CH2)p-, wherein p is an integer from 2 to 5, as well as to a composition of a petroleum hydrocarbon comprising a petroleum hydrocarbon and at least one chemical marker of general formula (I).The presence and concentration of the chemical marker of general formula (I) in the composition of the petrolem hydrocarbon can be advantageously determined by laser ionization coupled with mass spectrometry or laser ionization coupled with ion mobility spectrometry.

Description

wherein the residues A and B are independently of each other selected from the group consisting of R⁷, NR^aR^b and NR^cR^d, with the proviso that at least one of the residue A and B represents NR^aR^b; the residues R¹-R⁶ are independently of each other selected from the group consisting hydrogen, Ci-Ce-alkyl and NR^eR^f ; the residue R⁷is selected from the group consisting of hydrogen and CiCe-alkyl or alternatively, the substituents R^a and R^b are independently of each other selected from Ci-Ce-alkyl or alternatively, substituents R^a and R^b taken together from a residue -(CH2)n-, wherein n is an integer from 2 to 5; the substituents R^c and R^d are independently of each other selected from Ci-Ce-alkyl, or alternatively the substituents R^c and R^d taken together from a residue -(CH2)m-, wherein m is an integer from 2 to 5 and the substituents R^e and R^fare independently of each other selected from Ci-Ce-alkyl or alternatively, the substituents R^e and R^f taken together from a residue -(CH2)p-, wherein p is an integer from 2 to 5, wherein the residues A and B are independently of each other selected from the group consisting of R⁷, NR^aR^b and NR^cR^d, with the proviso that at least one of the residue A and B represents NR^aR^b; the residues R¹-R⁶ are independently of each other selected from the group consisting hydrogen, Ci-Ce-alkyl and NR^eR^f ; the residue R⁷

Method for marking a petroleum is selected from the group consisting of hydrogen and CiCe-alkyl or alternatively, the substituents R^a and R^b are independently of each other selected from Ci-Ce-alkyl or alternatively, substituents R^a and R^b taken together from a residue -(CH2)n-, wherein n is an integer from 2 to 5; the substituents R^c and R^d are independently of each other selected from Ci-Ce-alkyl, or alternatively the substituents R^c and R^d taken together from a residue -(CH2)m-, wherein m is an integer from 2 to 5 and the substituents R^e and R^fare independently of each other selected from Ci-Ce-alkyl or alternatively, the substituents R^e and R^f taken together from a residue -(CH2)p-, wherein p is an integer from 2 to 5, as well as to a composition of a petroleum hydrocarbon comprising a petroleum hydrocarbon and at least one Chemical marker of general formula (l).The presence and concentration of the Chemical marker of general formula (I) in the composition of the petrolem hydrocarbon can be advantageously determined by laser ionization coupled with mass spectrometry or laser ionization coupled with ion mobility spectrometry.

• Gasoline • Diesel

Hexane

1,0

0,8

0,6 & VI

0.4 c

0,2

2000 4000 6000 S000 10000

Fig. 2c Final Marker Concentration / nM

O.A.P.I. - B.P. 887, YAOUNDE (Cameroun) - Tel. (237) 222 20 57 00-Site web: http:/www.oapi.int- Email: oapi@oapi.int

METHOD FOR MARKING A PETROLEUM HYDROCARBON

FIELD OF THE INVENTION

The présent invention relates to the technical field of methods for marking a Petroleum hydrocarbon with a Chemical marker and chemically marked petroleum hydrocarbons.

BACKGROUND OF THE INVENTION

Marking of petroleum hydrocarbons with the scope of auditing the custody transfer of such Products, to prevent and/or prove theft and/or counterfeiting is of great importance for the petroleum industry. In addition, marking of petroleum hydrocarbon may be also used to control whether a distributor has sold a low-priced petroleum hydrocarbon as a more 15 expensive petroleum hydrocarbon or has used a low-priced petroleum hydrocarbon to dilute a more expensive petroleum hydrocarbon.

Additionally, national governments are interested in technical solutions that allow to détermine whether applicable taxes hâve been paid on petroleum hydrocarbons, whether 20 tax exempt petroleum hydrocarbons are being sold as tax paid petroleum hydrocarbons or if they are being used to dilute tax paid petroleum hydrocarbons, and whether a petroleum hydrocarbon, which meets environmentally mandated spécifications has been diluted with a product that does not meet such spécifications.

A limited number of Chemical markers for tagging petroleum hydrocarbons and methods for detecting said markers in the tagged products hâve been described.

The use of halogenated compounds, such as halogenated alkanes, halogenated olefins and halogenated aromatic compounds (WO02098199A2), perfluorinated 30 C9-C18 polycyclic hydrocarbons (EP0120641A2), chlorinated hydrocarbons and chlorocarbons (US4141692), and brominated or fluorinated benzene and naphthalene dérivatives (WO2012153132A1), as tracers for marking a hydrocarbon liquid, as well as their détection by gas chromatography - mass spectrometry (WO2012153132A1), gas chromatography - électron capture détection (EP0120641A2, US4141692) or X-ray 35 fluorescence (WO02098199A2) hâve been previously described.

Aryl ethers, including bis(alkyloxy)-1 ,Τ-biphenyl dérivatives (WO2013003573A1), bis(phenoxymethyl)-1,1’-biphenyl dérivatives (US20120090225A1), alkyl aryl ethers and alkenyl aryl ethers (WO2014081556A1), ortfto-phenyl phénol ethers (WO2012154646A1), tritylated alkyl aryl ethers (WO2014008164A1), bisphenol A substituted benzyl ethers (US20140179955A1), deuterated bis(4(alkyloxy)phenyl)sulfane dérivatives (US9366661B1) and deuterated 4,4’oxybis((alkyloxy)benzene dérivatives (US9366661B1) are also known as Chemical markers for petroleum hydrocarbons. The détection of such type of Chemical markers include gas-chromatography - flame ionization détection (WO2013003573A1), gas chromatography - mass spectrometry (US20120090225A1, WO2012154646A1, WO2014008164A1, US20140179955A1, US9366661B1) and two-dimensional gas chromatography coupled with mass spectrometry (WO2014081556A1).

Further, US patent application publication number US2014008164A1 describes the use of 4,4’-bis(benzyl)-1,1 ’-biphenyl dérivatives as Chemical markers for liquid hydrocarbons and gas chromatography as détection technique of such Chemical markers.

US patent application publication number US2011290997A1 discloses the use of 1,3diphenyl-2-buten-1-one dérivatives for marking a petroleum hydrocarbon and gas chromatography - mass spectrometry for détection of such Chemical markers.

International patent application publication number WO2004068113A2 describes a method of marking a fuel with a Chemical marker of general formula RCAR', wherein R is a compound selected from the group consisting of alkyl, olefin, aryl, heterocycle and hydrogen; R' is a compound selected from the group consisting of alkyl, olefin, aryl, heterocycle and hydrogen; and wherein A is a compound selected from the group consisting of ketones, alcohol, amines, cyano, sulfate, nitrile, nitrate, halogen, organic acid, mercaptan, aldéhyde, formyl, thiocyano, and isothiocyano, and the use of ion mobility spectrometry for détection of said Chemical marker. The ion mobility spectrometry détection method described by WO2004068113A2 uses nickel 63 (⁶³Ni) as ionization source, which results in unselective ionization of the sample generally leading to difficult identification of the marker ion peak among the multitude of fuel matrix ion peaks.

The main disadvantage associated with the use of Chemical markers whose détection and eventual quantification relies upon the use of the gas chromatography (GC) is that the GO column used in the séparation of the marked petroleum hydrocarbon components has to be frequently replaced as a resuit of contaminations caused by the high amount of Petroleum hydrocarbon components injected on the column. For the Chemical markers whose détection and quantification techniques rely upon the use of gas chromatography - mass spectrometry (GC-MS), the frequent cleaning and/or replacement of the ionization source of the mass spectrometer is additionally required.

Because of the limited number of currently available Chemical markers for tagging Petroleum hydrocarbon products and the different disadvantages associated with some of them, such as light and heat instability in the marked petroleum hydrocarbon, insolubility in the marked petroleum hydrocarbon, toxicity, unsatisfactory counterfeit-resilience and unsatisfactory laundering résistance, there is a constant need for the development of additional Chemical markers to satisfy the high demand from government bodies and the petroleum industry.

In selecting a suitable Chemical marker several factors must be taken into considération. Among the major ones are: cost, ease of détection, stability, solubility and compatibility with the petroleum hydrocarbon, inertness to air, water and normal soil components, corrosivity, volatility and toxicity.

The problem addressed by the présent invention is to provide additional Chemical compounds for marking petroleum hydrocarbons, in particular high tax petroleum hydrocarbons to prevent counterfeiting of said petroleum hydrocarbons.

SUMMARY OF THE INVENTION

Accordingly, it is the object of the présent invention to provide a composition of a petroleum hydrocarbon comprising:

a petroleum hydrocarbon; and at least one Chemical marker of general formula (I) uniformly mixed with the petroleum hydrocarbon

wherein the residues A and B are independently of each other selected from the group consisting of R⁷, NR^aR^b and NR^cR^d, with the proviso that at least one of the residues A and B represents NR^aR^b;

the residues R¹ - R^B are independently of each other selected from the group consisting of hydrogen, Ci-Ce-alkyl and NR^eR^f;

the residue R⁷ is selected from the group consisting of hydrogen and Ci-Ce-alkyl;

the substituents R^a and R^b are independently of each other selected from Ci-Ce-alkyl or alternatively, the substituents R^a and R^b taken together form a residue -(CHz)n-, wherein n is an integer from 2 to 5;

the substituents R^c and R^d are independently of each other selected from Ci-Ce-alkyl, or alternatively the substituents R^c and R^d taken together form a residue -(CHajm-, wherein m is an integer from 2 to 5; and the substituents R® and R^f are independently of each other selected from Ci-Ce-alkyl, or alternatively the substituents R® and R^f taken together form a residue -(CH2)_P-, wherein p is an integer from 2 to 5.

Minute quantities of a tertiary naphthyl amine of general formula (I) in a petroleum hydrocarbon are easily détectable, identifiable and quantifiable after sample vaporization by laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with mass spectrometry or by laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with ion mobility spectrometry. Sample vaporization followed by laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with mass spectrometry, or by laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with ion mobility spectrometry enables identification and quantification of a tertiary naphthyl amine of general formula (I) in a petroleum hydrocarbon, and thereby determining the authenticity of said petroleum hydrocarbon and/or detecting the adultération of said petroleum hydrocarbon. Détection of the peak corresponding to the ion (M⁺) of the tertiary naphthyl amine of general formula (I) in the mass spectrum or the ion mobility spectrum (i.e. identification of the tertiary naphthyl amine of general formula (I)) is indicative of the authenticity of said petroleum hydrocarbon. As well known to the skilled person adultération of a petroleum hydrocarbon refers to altering, mixing, diluting, laundering, etc., ofthe petroleum hydrocarbon. In some cases, a petroleum hydrocarbon (e.g. a petroleum hydrocarbon taxed at a higher rate) can be combined (e.g. illegally) with another petroleum hydrocarbon (e.g. an untaxed petroleum hydrocarbon or petroleum hydrocarbon taxed at a lower rate) or solvent to form an adulterated (e.g., altered, mixed, diluted, laundered, etc.) petroleum hydrocarbon. For example, a petroleum hydrocarbon can be mixed with one or more other petroleum hydrocarbons, solvents, and the like, or combinations thereof. If undetected, the adulterated petroleum hydrocarbon can be sold, sometimes illegally, at the price of the petroleum hydrocarbon taxed at the higher rate to yield a profit. In some instances, the adulterated petroleum hydrocarbon can be potentiaily hazardous for the user, such as for example when a hazardous solvent is used for adulterating the petroleum hydrocarbon. In other instances, the petroleum hydrocarbon can be treated or laundered in an attempt to remove identifying features, such as Chemical markers from the petroleum hydrocarbon (e.g. to disguise the origin of the petroleum hydrocarbon the amount of tax paid on the petroleum hydrocarbon, etc.) before the petroleum hydrocarbon is mixed with another petroleum hydrocarbon to form an adulterated petroleum hydrocarbon. Chemical marking of a petroleum hydrocarbon with a tertiary naphthyl amine of general formula (I) renders the above-described adultération activities difficult and constitutes an extremely useful tool for proving and/or preventing counterfeiting of said petroleum hydrocarbon. The Chemical markers of general formula (I) are inert to air, water and soil components, as well as conventional petroleum hydrocarbon components, and they are non-corrosive. Further, they are commercially available at low cost or can be obtained by well-established organic chemistry methods, and their détection and quantification methods do not suffer from the drawbacks encountered for the GC-MS based détection and quantification methods. Moreover, the Chemical markers of general formula (I) are relatively non-toxic and do not produce harmful products upon combustion.

Further claimed and described herein is a method for marking a petroleum hydrocarbon to prevent counterfeiting of said petroleum hydrocarbon, wherein said method comprises adding to and uniformly mixing with said petroleum hydrocarbon at least one Chemical marker of general formula (I)

wherein the residues A and 13 are independently of each other selected from the group consisting of R⁷, NR^aR^b and NR^cR^d, with the proviso that at least one of the residues A and B represents NR^aR^b;

the residues R¹ - R³ are independently of each other selected from the group consisting of hydrogen, Ci-Ce-alkyl and NR^eR^f;

the substituents R^a and R^b are independently of each other selected from Ci-Ce-alkyl or alternatively, the substituents R^a and R^b taken together form a residue -(CH2)n-, wherein n is an integer from 2 to 5;

the substituents R^c and R^d are independently of each other selected from Ci-Cs-alkyl, or alternatively the substituents R^c and R^d taken together form a residue -(CH2)m-, wherein m is an integer from 2 to 5; and the substituents R® and R^f are independently of each other selected from Ci-Cs-alkyl, or alternatively the substituents R® and R^f taken together form a residue -(CH2)_P-, wherein p is an integer from 2 to 5.

FIGURES

Fig. 1a illustrâtes the mass spectrum of a composition of diesel containing the Chemical marker N\ N¹, N⁵, A/⁵-tetraethyl-naphthalene-1,5-diamine obtained by laser ionization at 355 nm coupled with mass spectrometry. The peak corresponding to the ion (M⁺) of the Chemical marker (m/z of 270) is indicated by a

Fig. 1b illustrâtes the mass spectrum of a composition of gasoline containing the Chemical marker N¹, N¹, N⁵, A/⁵-tetraethyl-naphthalene-1,5-diamine obtained by laser ionization at 355 nm coupled with mass spectrometry. The peak corresponding to the ion (M⁺) of the Chemical marker (m/z of 270) is indicated by a “*”.

Fig. 1c illustrâtes the variation of the intensity of the peak corresponding to the molecular ion (M⁺) of the Chemical marker N¹, N¹, N⁵, /\/⁵-tetraethyl-naphthalene-1,5-diamine with the concentration of the Chemical marker in a composition of diesel and a composition of hexane. The compositions of diesel and hexane containing the Chemical marker N¹, N¹, N⁵, A/⁵-tetraethyl-naphthalene-1,5-diamine were analyzed by laser ionization at 355 nm coupled to mass spectrometry.

Fig. 2a illustrâtes the superimposed ion mobility spectra of a composition of hexane containing the Chemical marker N¹, N¹, N⁵, A/⁵-tetraethyl-naphthalene-1,5-diamine at a concentration of 2 μΜ (black colored spectrum) and of an unmarked diesel (grey colored spectrum) obtained by laser ionization at 355 nm coupled with ion mobility spectrometry. The Chemical marker is characterized by a drift time of about 7.4 ms.

Fig. 2b illustrâtes the superimposed ion mobility spectra of a composition of hexane containing the Chemical marker N¹, N¹, N⁵, A/Metraethyl-naphthalene-l ,5-diamine (black colored spectrum) and of an unmarked gasoline (grey colored spectrum) obtained by laser ionization at 355 nm coupled with ion mobility spectrometry. The Chemical marker is characterized by a drift time of about 7.4 ms.

Fig. 2c illustrâtes the variation of the intensity of the peak corresponding to the ion (M⁺) of the Chemical marker N¹, N¹, N⁵, /V⁵-tetraethyl-naphthalene-1,5-diamine with the marker concentration in a composition of diesel, a composition of gasoline and a composition of hexane. The compositions of diesel, gasoline and hexane containing the Chemical marker N¹, N¹, N⁵, A/⁵-tetraethyl-naphthalene-1,5-diamine were analyzed by laser ionization at 355 nm coupled with ion mobility spectrometry.

Fig. 3a illustrâtes the mass spectrum of a composition of diesel containing the Chemical marker A/,/\/-dimethylnaphthalen-1-amine obtained by laser ionization at 308 nm coupled with mass spectrometry. The peak corresponding to the ion (M⁺)of the Chemical marker (m/z of 171) is indicated by a “*”.

Fig. 3b illustrâtes the mass spectrum of a composition of gasoline containing the Chemical marker A/,A/-dimethylnaphthalen-1-amine obtained by laser ionization at 308 nm coupled with mass spectrometry. The peak corresponding to the ion (M⁺)of the Chemical marker (m/z of 171) is indicated by a

DETAILED DESCRIPTION

Définitions

The following définitions are to be used to interpret the meaning of the terms discussed in the description and recited in the daims.

As used herein, the article a/an” indicates one as well as more than one and does not necessarily limit its referent noun to the singular.

As used herein, the term “about” means that the amount or value in question may be the spécifie value designated or some other value in its neighbourhood. Generally, the term “about” denoting a certain value is intended to dénoté a range within ± 5% of the value. As one example, the phrase “about 100” dénotés a range of 100 ± 5, i.e. the range from 95 to 105. Preferabiy, the range denoted by the term “about” dénotés a range within ± 3% of the value, more preferabiy ± 1 %. Generally, when the term “about” is used, it can be expected that similar results or effects according to the invention can be obtained within a range of ±5% of the indicated value.

As used herein, the term “and/or” means that either ail or only one of the éléments of said group may be présent. For example, “A and/or B” means “only A, or only B, or both A and B”. In the case of “only A”, the term also covers the possibility that B is absent, i.e. “only A, but not B”.

The term “comprising” as used herein is intended to be non-exclusive and open-ended. Thus, for instance a solution comprising a compound A may include other compounds besides A. However, the term “comprising” also covers, as a particular embodiment thereof, the more restrictive meanings of “consisting essentially of’ and “consisting of’, so that for instance “a solution comprising A, B and optionally C” may also (essentially) consist of A and B, or (essentially) consist of A, B and C.

Where the présent description refers to “preferred” embodiments/features, combinations of these “preferred” embodiments/features are also deemed to be disclosed as long as the spécifie combination of “preferred” embodiments/features is technically meaningful.

Surprisingly, it has been found that minute quantities of a tertiary naphthyl amine of general formula (I) in a petroleum hydrocarbon can be detected, identified and quantified following vaporization by laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with mass spectrometry, or by laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with ion mobility spectrometry. Sample vaporization followed by laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with mass spectrometry, or by laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with ion mobility spectrometry, enables identification and quantification of the tertiary naphthyl amine of general formula (I) in a Petroleum hydrocarbon, and thereby confirming the authenticity of said petroleum hydrocarbon and/or detecting the adultération of said petroleum hydrocarbon.

Additionally, it has been found that the tertiary naphthyl amines of general formula (I) are soluble in a variety of petroleum hydrocarbons at marking concentrations of commercial interest, and consequently, they are useful for chemically marking petroleum hydrocarbons.

Thus, the présent invention provides a composition of a petroleum hydrocarbon comprising:

the residues R¹ - R'⁵ are independently of each other selected from the group consisting of hydrogen, Ci-Ce-alkyl and NR^eR^f;

the substituents R^a and R^b are independently of each other selected from Ci-Ce-alkyl or alternatively, the substituents R^a and R^b taken together form a residue -(CHajn-, wherein n is an integer from 2 to 5;

the substituents R^c and R^d are independently of each other selected from Ci-Ce-alkyI, or alternatively the substituents R^c and R^d taken together form a residue -(CH2)m-, wherein m is an integer from 2 to 5; and the substituents R^e and R^f are independently of each other selected from Ci-Ce-alkyl, or alternatively the substituents R® and R^f taken together form a residue -(CHajp-, wherein p is an integer from 2 to 5.

Another aspect of the présent invention is directed to a method for marking a petroleum hydrocarbon to prevent counterfeiting of said petroleum hydrocarbon, wherein said method comprises adding to and uniformly mixing with said petroleum hydrocarbon at least one Chemical marker of general formula (I)

the residues R¹ - R'⁵ are independently of each other selected from the group consisting of hydrogen, Ci-Cs-alkyl and NR^eR^f;

the substituents R^c and R^d are independently of each other selected from Ci-Ce-alkyl, or alternatively the substituents R^c and R^d taken together form a residue -(CH2)m-, wherein m is an integer from 2 to 5; and the substituents R® and R^f are independently of each other selected from Ci-Ce-alkyl, or alternatively the substituents R^e and R^f taken together form a residue -(CH2)_P-, wherein p is an integer from 2 to 5.

The term petroleum hydrocarbon refers to products having a predominantly hydrocarbon composition, although they may contain minor amounts of oxygen, nitrogen, sulfur or phosphorus. As used herein, the term “petroleum hydrocarbon” includes crude oils, as well as products derived from petroleum refining processes. Preferably, a “petroleum hydrocarbon” includes without limitation crude oil, lubricating oil, hydraulic fluid, brake fluid, gasoline, diesel fuel, kerosene, jet fuel, heating oil and heavy fuel oil. More preferably, the petroleum hydrocarbon is selected from the group consisting of gasoline and diesel fuel.

The term “Ci-Ce-alkyl group” as used herein refers to a saturated linear or branched-chain monovalent hydrocarbon radical of one to six carbon atoms (Ci-Ce). Examples of Ci-Ce alkyl groups include methyl (Me, -CH₃), ethyl (Et, -CH₂CH₃), 1-propyl (n-Pr, n-propyl, CH2CH2CH3), 2-propyl (/-Pr, /so-propyl, -CH(CH₃)₂), 1-butyl (n-Bu, n-butyl, CH2CH2CH2CH3), 2-methyl-1-propyl (/-Bu, /-butyl, -CH2CH(CH₃)2), 2-butyl (s-Bu, s-butyl, -CH(CH₃)CH₂CH₃), 2-methyl-2-propyl (t-Bu,f-butyl, -C(CH₃)₃), 1-pentyl (n-pentyl, CH2CH2CH2CH2CH3), 2-pentyl (-CH(CH₃)CH₂CH2CH3), 3-pentyl (-CH(CH₂CH₃)₂), 2-methyl-2-butyl (-C(CH3)2CH₂CH₃), 3-methyl-2-butyl (-CH(CH₃)CH(CH₃)2), 3-methyl-1 -butyl (-CH₂CH₂CH(CH₃)2), 2-methyl-1butyl (-CH₂CH(CH₃)CH₂CH₃), 1-hexyl (-CH2CH2CH2CH2CH2CH3), 2-hexyl (-CH(CH3)CH₂CH₂CH2CH3), 3-hexyl (-CH(CH₂CH₃)(CH₂CH₂CH₃)), 2-methyl-2-pentyl (-C(CH₃)₂CH₂CH₂CH₃), 3-methyl-2-pentyl (-CH(CH₃)CH(CH₃)CH₂CH₃), 4-methyl-2-pentyl (-CH(CH₃)CH2CH(CH₃)2), 3-methyl-3-pentyl (-C(CH₃)(CH₂CH₃)2), 2-methyl-3-pentyl (-CH(CH₂CH₃)CH(CH3)2), 2,3-dimethyl-2-butyl (-C(CH₃)₂CH(CH₃)2) and 3,3-dimethyl-2butyl (-CH(CH₃)C(CH₃)₃).

Preferably, the tertiary naphthyl amine of general formula (I) is characterized by a boiling point lower than about 600 °C at 760 mm Hg, more preferably lower than 500 °C at 760 mm Hg, and even more preferably lower than 450 °C at 760 mm Hg. Such a Chemical marker is particularly useful for marking high fax petroleum hydrocarbons, such as high tax kerosene and high tax diesel, because due to its boiling point that is within or close to the boiling range of the petroleum hydrocarbon, it renders difficult its isolation from the petroleum hydrocarbon matrix and its identification by criminals involved in dilution or substitution of high taxed petroleum hyclrocarbon with lower grade petroleum hydrocarbon, and thereby aids in minimizing the lost revenue caused by theses illégal activities, the risk of brand dégradation, as well as the environmental damage.

As demonstrated for example by Fig. 1a - Fig. 1c, Fig. 3a and Fig. 3b, the tertiary naphthyl amines of general formula (I) are easily détectable, identifiable and quantifiable in minute quantifies after sample vaporization by laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with mass spectrometry. Additionally, as demonstrated for example by Fig. 2a - Fig. 2c, the tertiary naphthyl amines of general formula (I) are easily détectable, identifiable and quantifiable in minute quantities after sample vaporization by laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with ion mobility spectrometry. As demonstrated by the data presented herein, the tertiary naphthyl amines of general formula (I) contained by a composition of a petroleum hydrocarbon can be selectively ionized, following sample vaporization, by illumination with pulsed laser light having a wavelength of 308 nm or 355 nm. The inventors hâve found that sélective ionization of the tertiary naphthyl amine of general formula (!) in a composition of petroleum hydrocarbon can be achieved by illumination with pulsed laser light having any wavelength of between about 300 nm and 370 nm, for example 308 nm, 337 nm and 355 nm.

In addition, the tertiary naphthyl amines of general formula (I) are inert to air, water and soil components, as well as conventional petroleum hydrocarbon components, and they are non-corrosive. Further, they are commercially available at low cost or can be obtained by well-established organic chemistry methods, and their détection and quantification methods do not suffer from the drawbacks encountered for the GC-MS based détection and quantification methods. Moreover, the tertiary naphthyl amines of general formula (I) are relatively non-toxic and do not produce harmful products upon combustion.

Preferably, the concentration of the at least one Chemical marker of general formula (!) in the composition claimed and described herein and the method of marking claimed and described herein is of at least 1 μΜ (micromolar). Depending on the petroleum hydrocarbon to be marked and the method used for the détection, identification and quantification of the Chemical marker, namely laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with mass spectrometry or laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with ion mobility spectrometry, higher concentration of the at least one Chemical marker of general formula (I) in the composition of petroleum hydrocarbon may be required. Owing to the high solubility of the Chemical marker of general formula (I) in a variety of petroleum hydrocarbons, even high marking concentration of about 1 mM (millimolar) may be considered. It remains within the skills of the person skilled in the art of petroleum hydrocarbon marking to détermine via routine work an adéquate marking concentration for a spécifie Chemical marker of general formula (I), taking into account the type of petroleum hydrocarbon to be marked, the method used for the détection, identification and quantification of said spécifie Chemical marker, namely laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with mass spectrometry or laser ionization at a wavelength of between about 300 nm and about 370 nm coupled with ion mobility spectrometry, as well as the cost of the Chemical marker.

An embodiment according to the présent invention is directed to a composition as claimed and described herein, as well as to a method for marking as claimed and described herein, wherein the at least one Chemical marker is of general formula (II),

wherein the residue B is selected from the group consisting of R⁷ and NR^cR^d;

the residues R¹ - R'³ are independently of each other selected from the group consisting of hydrogen and Ci-Ce alkyl; the residue R⁷ and the substituents R^a - R^d hâve the meanings defined herein.

A preferred embodiment according to the présent invention relates to a composition as claimed and described herein, as well as to a method for marking as claimed and described herein, wherein the at least one Chemical marker is of general formula (III)

wherein the residue R² represents NR^eR^f, the residues R¹, R³ - R⁶ are independently of each other selected from the group consisting of hydrogen and Ci-Ce alkyl, the substituents R^a, R^b, R® and R^f and the residue R⁷ hâve the meanings defined herein;

or the residue R³ represents NR^eR^f, the residues R¹, R², R⁴ - R⁶ are independently of each other selected from the group consisting of hydrogen and Ci-Ce-alkyl, the substituents R^a, R^b, R® and R^f and the residue R⁷ hâve the meanings defined herein;

or the residue R⁶ represents NR^eR^f, the residues R¹ - R⁵ are independently of each other selected from the group consisting of hydrogen and Ci-Ce-alkyl, the substituents R^a, R^b, R® and R^f and the residue R⁷ hâve the meanings defined herein. Thus, a preferred Chemical marker to be used in the composition claimed and described herein and the method for marking claimed and described herein is a compound of general formula (IIIa)

wherein the residues R¹, R³ - R⁶ are independently of each other selected from the group consisting of hydrogen and Ci-Ce-alkyl, and the substituents R^a, R^b, R® and R^f and the residue R⁷ hâve the meanings defined herein;

as well as a compound of general formula (lll-b)

wherein the residues R¹, R², R⁴ - R⁶ are selected from the group consisting of hydrogen and C-i-Ce-alkyl, and the substituents R^a, R^b, R® and R^f and the residue R⁷ hâve the meanings defined herein;

and a compound of general formula (lll-c)

wherein the residues R¹ - R⁵ are selected from the group consisting of hydrogen and Ci-Ce alkyl, and the substituents R^a, R^b, R® and R^f and the residue R⁷ hâve the meanings defined herein.

In the general formulae (III), (ΙΙΙ-a), (lll-b) and (lll-c) it is preferred that the substituents R^a, R^b, R® and R^f are the same. In other words, Chemical markers of general formula (III), (IIIa), (lll-b) and (lll-c), wherein R^a= R^b= R® = R^fare preferred. Such Chemical markers can be directly obtained from the corresponding commercially available di-amino naphthalene precursors by simple treatment with an alkyl halide (for e.g. an alkyl bromide of general formula R^aBr or an alkyl iodide of general formula R^al) in presence of a base, such as N,N(diisopropyl)ethyl amine or sodium hydride.

A further embodiment according to the présent invention is directed to a composition as claimed and described herein, as well as a method for marking a petroleum hydrocarbon as claimed and described herein, wherein the at least one Chemical marker is of general formula (IV)

wherein the residues R¹ - R^fi are independently of each other selected from the group consisting of hydrogen and Ci-Ce-alkyl; and the substituents R^a and R^b, as well as the residue R⁷hâve the meanings defined herein;

or the residue R¹ represents NR^eR^f, the residues R² - R⁶ are independently of each other selected from the group consisting of hydrogen and Ci-Ce-alkyl, and the substituents R^a, R^b, R® and R^f, as well as the residue R⁷ hâve the meanings defined herein;

or the residue R⁴ represents NR^eR^f, the residues R¹ - R³, R⁵ and R⁶ are independently of each other selected from the group consisting of hydrogen and Ci-Cs alkyl, and the substituents R^a, R^b, R®and R^f, as well as the residue R⁷ hâve the meanings defined herein;

the residue R⁵ represents NR^eR^f, the residues R¹ - R⁴ and R⁶ are selected from the group consisting of hydrogen and Ci-C₆alkyl, and the substituents R^a, R^b, R® and R^f, as well as the residue R⁷ hâve the meanings defined herein. Hence, a preferred Chemical marker to be used in the composition claimed and described herein and the method for marking claimed and described herein is a compound of general formula (IV-a) wherein the residues R² - R⁶ are selected from the group consisting of hydrogen and Ci-C₆ alkyl, and the substituents R^a, R^b, R® and R^f, as well as residue R⁷ hâve the meanings defined herein;

as well as a compound of general formula (IV-b) wherein the residues R¹ - R³, R⁵ and R⁶ are selected from the group consisting of hydrogen and Ci-C₆ alkyl, and the substituents R^a, R^b, R® and R^f, as well as the residue R⁷ hâve the meanings defined herein;

and a compound of general formula (IV-c)

wherein the residues R¹ - R⁴ and R⁶ are selected from hydrogen and Ci-Ce alkyl, and the substituents R^a, R^b, R® and R^f and the residue R⁷ hâve the meanings defined herein.

In a preferred embodiment, the residues R¹ - R⁶ other than NR^eR^f are independently of each other selected from hydrogen and Ci-C4-alkyl. In a more preferred embodiment, the residues R¹ - R⁶ other than NR^eR^f represent hydrogen.

The residue R⁷ is preferabiy selected from the group consisting of hydrogen and C1-C4alkyl, and more preferabiy the residue R⁷ represents hydrogen.

Examples of the at least one Chemical marker of general formula (I), include but are not limited to: A/,A/-dimethylnaphthalen-1 -amine (CAS no.: 86-56-6; provider: Alchem Pharmtech); A/-ethyl-/V-methyl-naphthalen-1-amine (CAS no.: 83777-94-0; provider: Chemieliva Pharmaceutical); /\/,/\/,4-trimethylriaphthalen-1 -amine (CAS no.: 4523-52-8; provider: ASW MedChem); /V,/V,5-trimethylnaphthalen-1-amine (CAS no.: 847449-78-9; provider: Chemieliva Pharmaceutical), /V,/V,2-trimethylnaphthalen-1 -amine (CAS no.: 57585-25-8; provider: Chemieliva Pharmaceutical); A/,/\/-diethyinaphthalen-1 -amine (CAS no.: 84-95-7; provider: ASW MedChem); /V-isopropyl-A/-methylnaphthalen-1-amine (CAS no.: 110014-41-0; provider: Chemieliva Pharmaceutical); /V,/\/,4,5-tetramethylnaphthalen1-amine (CAS no.: 4619-41-4; provider: Chemieliva Pharmaceutical); A/-ethyl-/Visopropylnaphthalen-1-amine (CAS no.: 114326-20-4; provider: Chemieliva Pharmaceutical); /V-ethyl-/V,2-dimethylnaphthalen-1-amine (CAS no.: 130523-07-8; provider: Chemieliva Pharmaceutical); A/,A/-bis(1-methylethyl)-naphthalen-1-amine (CAS no.: 4960-24-1; provider: Chemieliva Pharmaceutical); Λ/-(1, 1-dimethylethyl)-/\/-methylnaphthalen-1-amine (CAS no.: 110014-43-2; provider: Chemieliva Pharmaceutical); /V¹,/V¹,/V⁵,/\/⁵-tetramethyl-naphthalene-1,5-diamine (CAS no.: 10075-69-1; provider: Chemieliva Pharmaceutical); Λ/¹ ,Λ/¹ ,/\/⁴,/\/⁴-tetramethyl-naphthalene-1,4-diamine (CAS no.: 13764-14-2; provider: Chemieliva Pharmaceutical); Λ/-(1-ethylpropyl)-/V-methyl naphthalen-1-amine (CAS no.: 110014-42-1; provider: Chemieliva Pharmaceutical); N,2dimethyl-A/-(1-methylethyl)-naphthalen-1 -amine (CAS no.: 130523-08-9; provider: Chemieliva Pharmaceutical); Λ/¹ ,Λ/¹ ,/\/⁸,/\/⁸-tetramethyl-naphthalene-1,4-diamine (CAS no.: 20734-58-1; provider: ASW MedChem); /V,A/-diethyl-2-methyl-naphthalen-1 -amine (CAS no.: 21614-05-1; provider: Chemieliva Pharmaceutical); A/,/V-diethyl-8-methylnaphthalen-1-amine (CAS no.: 130523-22-7; provider: Chemieliva Pharmaceutical); N(2,2-dimethylpropyl)-A/-methyl-naphthalene-1-amine (CAS no.: 110014-40-9; provider: Chemieliva Pharmaceutical); A/-(2,2-dimethylpropyl)-/\/-ethyl-naphthalene-1-amine (CAS no.: 114326-22-6; provider: Chemieliva Pharmaceutical); /V,2-diethyl-A/-methylnaphthalene-1-amine (CAS no.: 130523-10-3; provider: Chemieliva Pharmaceutical); A/,/V-dibutyl-naphthalene-1-amine (CAS no.: 204126-63-6; provider: Chemieliva Pharmaceutical); /V-ethyl-2-methyl-/\/-(1-methylethyl)-naphthalene-1 -amine (CAS no.: 130523-09-0; provider: Chemieliva Pharmaceutical); 2-ethyl-/\Z-methyl-/V-(1 -methylethyl)naphthalene-1-amine (CAS no.: 130523-12-5; provider: Chemieliva Pharmaceutical); N¹ethyl-A/¹ ,/\/⁸,/\/⁸-trimelthyl-naphthaIene-1,8-diamine (CAS no.: 79687-92-6; provider: Chemieliva Pharmaceutical); /\/-ethyl-/\/-(1-ethylpropyl)-naphtahalene-1-amine (CAS no.: 114326-21-5; provider: Chemieliva Pharmaceutical); A/-ethyl-A/-methy 1-2-(1 -methylethyl)naphtahalene-1-amine (CAS no.: 130523-14-7; provider: Chemieliva Pharmaceutical); 8butyl-/\/,/\/-dimethyl-riaphtahalene-1 -amine (CAS no.: 1469538-06-4; provider: Chemieliva Pharmaceutical); /V,/V-bis(2-methylpropyl)-naphtahalene-1-amine (CAS no.: 109556-561; provider: Chemieliva Pharmaceutical); /V,N,2-triethyl-naphthalene-1-amine (CAS no.: 130523-11-4; provider: Chemieliva Pharmaceutical); /V,2-diethyl-/V-(1-methylethyl)naphthalene-1-amine (CAS no.: 130523-13-6; provider: Chemieliva Pharmaceutical); Nmethyl-/\/,2-bis(1-methylethyl)-naphthalene-1 -amine (CAS no.: 130523-16-9; provider: Chemieliva Pharmaceutical); A/,A/-diethyl-2-(1-methylethyl)-naphthalene-1 -amine (CAS no.: 130523-15-8; provider: Chemieliva Pharmaceutical); 2-(1, 1 -dimethylethyl)-A/-ethyl-A/methyl-naphthalene-1-amine (CAS no.: 130523-18-1; provider: Chemieliva Pharmaceutical); Λ/¹,N\N⁸,/V⁸-tetraethyl-naphthalene-1,8-diamine (CAS no.: 53463-80-2; provider: Chemieliva Pharmaceutical); A/¹,A/',A/⁵,A/⁵-tetraethyl-naphthalene-1,5-diamine (CAS no.: 861347-34-4); A/¹ ,/\/⁵-dimethyl-/\/¹ ,/\/⁵-bis(1-methylethyl)-naphthalene-1,5diamine (CAS no.: 110971-36-3; provider: Chemieliva Pharmaceutical); A/-ethyl-/V,2bis(1-methylethyl)-naphthalene-1-amine (CAS no.: 130523-17-0; provider: Chemieliva Pharmaceutical); 2-(1,1-dimethylethyl)-A/-methyl-/\/-(1-methylethyl)-naphthalene-1-amine (CAS no.: 130523-20-5; provider: Chemieliva Pharmaceutical); 2-(1,1-dimethylethyl)-/V,A/diethyl-naphthalene-1-amine (CAS no.: 130523-19-2; provider: Chemieliva Pharmaceutical); 3-butyl-/V,A/-diethyl-naphthcilene-1-amine (CAS no.: 398458-74-7;

provider: Chemieliva Pharmaceutical); 2-(1,1-dimethylethyl)-/V-ethyl-A/-(1-methylethyl)naphthalene-1-amine (CAS no.: 130523-21-6; provider: Chemieliva Pharmaceutical); Λ/¹butyl-A/¹,A/⁸,/\/⁸-trimethyl-naphthalene-1,8-diamine (CAS no.: 852630-17-2, provider: Chemieliva Pharmaceutical); N¹ ,A/⁸-dibutyl-A/¹ ,/\/⁸-dimethyl-naphthalene-1,8-diamine (CAS no.: 852630-27-4; provider: Chemieliva Pharmaceutical); A/,A/-dimethylnaphthalene-2-amine (CAS no.: 2436-85-3; provider: ASW MedChem); A/-ethyl-A/-methylnaphtahalene-1-amine (CAS no.: 68172-51-0; provider: Chemieliva Pharmaceutical); A/,/V,4-trimethyl-naphtahalene-2-amine (CAS no.: 4523-53-9; provider: Chemieliva Pharmaceutical); A/,/\/,1-trimethyl-naphtahalene-2-amine (CAS no.: 5672-92-4; provider: Chemieliva Pharmaceutical); /V,/\/-diethyl-naphtahalene-2-amine (CAS no.: 13672-17-8; provider: Chemieliva Pharmaceutical); A^Lmethyl-A/-(1-methylethy!)-naphtahalene-2amine (CAS no.: 110014-44-3; provider: Chemieliva Pharmaceutical); N,N,4,5tetramethyl-naphtahalene-2-amine (CAS no.: 4536-94-1; provider: Chemieliva Pharmaceutical), A/-butyl-A/-methyl-naphtahalene-2-amine (CAS no.: 872801-93-9; provider: Chemieliva Pharmaceutical); /V,A/-bis(1-methylethyl)-naphtahalene-2-amine (CAS no.: 92596-72-0; provider: Chemieliva Pharmaceutical); /V,A/-dibutyl-naphtahalene2-amine (CAS no.: 97943-52-7; provider: Chemieliva Pharmaceutical); A/,A/-bis(2methylpropyl)-naphthalene-2-amine (CAS no.: 109554-95-2; provider: Chemieliva Pharmaceutical); 1-(naphthalen-1-yl)piperidine (CAS no.: 62062-39-9; provider: Chemieliva Pharmaceutical); and A/,A/-dibutyl-1-methyl-naphthalene-2-amine (CAS no.: 92834-61-2; provider: Chemieliva Pharmaceutical).

The tertiary naphthyl amines of general formula (I) are either commercially available or obtained by well-known organic chemistry methods described in the literature. For example, the tertiary naphthyl amine of general formula (I) can be obtained as shown in the scheme below from the corresponding commercially available primary naphthyl amine by simple treatment with a commercially available alkyl halide (for e.g. an alkyl bromide of general formula RBr or an alkyl iodide of general formula RI, wherein R is a Ci-Ce-alkyl group) in presence of a base, such as /V,A/-(diisopropyl)ethyl amine or sodium hydride.

RX, X = Br or Cl

NaH, tetrahydrofuran or

RX, X = Br or Cl,

A/,A/-(diisopopyl)ethylamine acetonitrile, reflux

Alternatively, the tertiary naphthyl amine of general formula (I) can be obtained via a palladium-catalyzed Buchwald Hartwig reaction starting from commercially available naphthyl bromides and commercially available dialkyl amines. Introduction of Ci-Ce-alkyl substituents on the naphthalene core can be achieved by well-known organic chemistry reactions, such as naphthalene bromination followed by treatment of the brominated naphthalene with a Grignard reagent, such as Ci-Ce-alkylMgBr.

The composition claimed and described herein may contain a further Chemical marker which is structurally different from the herein described Chemical marker of general formula (I). Use of multiple Chemical markers facilitâtes incorporation into the petroleum hydrocarbon of coded information that may be used to identify the origin and other characteristics of the petroleum hydrocarbon. The code comprises the identifies and relative amounts, for example fixed integer ratios, of the Chemical markers. One, two, three or more Chemical marker compounds that are preferably détectable and quantifiable by laser ionization at a wavelength of between about 300 nm and about 370 nm (for e.g.: 308 nm, 337 nm, 355 nm) coupled with mass spectrometry or laser ionization at a wavelength of between about 300 nm and about 370 nm m (for e.g.: 308 nm, 337 nm, 355 nm) coupled with ion mobility spectrometry may be used to form the code. The at least one Chemical marker of general formula (I) may be combined with Chemical markers of other types such as:

i) a diphenyl-polyene dérivative of general formula (V)

R¹⁶ R¹⁷ r⁸ R⁹

wherein the residue -L- represents -CR^x=CR^y- wherein the residues R^x and R^y are independently of each other selected from the group consisting of hydrogen and methyl;

the residues R⁸ - R¹⁷ are independently of each other selected from the group consisting of hydrogen and Ci-C4-alkyl; and x is an integer comprised between 2 and 6;

ii) a naphtacene dérivative of general formula (VI)

wherein the residues R¹⁸ - R²⁹ are independently of each other selected from the group consisting of hydrogen, Ci-C4-alkyl and phenyl optionally substituted by one or more groups selected from Ci-C₄-alkyl, with the proviso that at least two of the residues R¹⁸ R²⁹ represent a phenyl optionally substituted by one or more groups selected from C1-C4alkyl;

iii) an aromatic compound substituted by at least one group selected from CiC₄-alkyloxy.

Preferably, the diphenyl-polyene of general formula (V) is characterized by a boiling point lower than about 600 °C at 760 mm Hg, more preferably lower than about 500 °C at 760 mm Hg, and even more preferably lower than 450 °C at 760 mm Hg. Examples of diphenyl-polyene of general formula (V) include but are not limited to: 6-diphenyl-1,3,5-hexatriene (CAS. no.: 1720-32-7; provider: Sigma Aldrich); (1E,3E)-1,4diphenylbuta-1,3-diene (CAS no.: 538-81-8; provider: ASW MedChem); ((7E,3E)-penta1,3-diene-1,4-diyl)dibenzene (CAS no.: 23637-42-5; provider: Chemileva Pharmaceutical); 1-methyl-4-((7E,3E)-4-phenylbuta-1,3-dien-1-yl)benzene (CAS no.: 37985-11-8; provider: Chemileva Pharmaceutical); ((1E,3E)-2-methylbuta-1,3-diene-1,4diyl)dibenzene (CAS no.: 23637-43-6; provider: Chemileva Pharmaceutical); ((2E,4E)hexa-2,4-diene-2,5-diyl)dibenzene (CAS no.: 16914-12-8; provider: Chemileva Pharmaceutical); 1-methyl-2-((7E,3E)-4-phenylbuta-1,3-dien-1-yl)benzene (CAS no.: 93333-38-1; provider: Chemileva Pharmaceutical); 1-methyl-3-((7E,3E)-4-phenylbuta1,3-dien-1-yl)benzene (CAS no.: 82102-26-9; provider: Chemileva Pharmaceutical); (7E,3E)-1,4-di-o-tolylbuta-1,3-diene (CAS no.: 848354-92-7; provider: Shanghai Chemhere Co.); (7E,3E)-1,4-di-m-tolylbuta-1,3-diene (CAS no.: 1261146-08-0; provider: Chemileva Pharmaceutical); (7E,3E)-1,4-di-p-tolylbuta-1,3-diene (CAS no.: 72033-82-0; provider: Chemileva Pharmaceutical); ((7E,3E)-2-methylpenta-1,3-diene-1,4diyl)dibenzene (CAS no.: 117847-11-7; provider: Chemileva Pharmaceutical); ((1E,3E)2,3-dimethylbuta-1,3-diene-1,4-diyl)dibenzene (CAS no.: 54631-95-7; provider: Shanghai Chemhere Co.); 1-methyl-4-((7E,3E)-3-methyl-4-phenylbuta-1,3-dien-1-yl)benzene (CAS no.: 916764-21-1; provider: Chemileva Pharmaceutical); (7E,3E)-1,4-di-m-tolylbuta-1,3diene (CAS no.: 12611146-10-4; provider: Chemileva Pharmaceutical); 4,4'-((7E,3E)-2methylbuta-1,3-diene-1,4-diyl)bis(methylbenzene) (CAS no.: 102080-29-5; provider: Chemileva Pharmaceutical); (7E,3E)-1,4-dimesitylbuta-1,3-diene (CAS no.: 1261146-091; provider: Chemileva Pharmaceutical); 4,4'-((2E,4E)-hexa-2,4-diene-2,5diyl)bis(methylbenzene) (CAS no.: 110746-28-6; provider; Chemileva Pharmaceutical); 1,2,4,5-tetramethyl-3-((7E,3E)-4-phenylbuta-1 3-dien-1-yl)benzene (CAS no.: 39117-470; provider: Chemileva Pharmaceutical); (7E,3E)-1,4-bis(2,4,5-trimethylphenyl)buta-1,3diene (CAS no.: 96214-75-4; provider: Chemileva Pharmaceutical); (7Z,3Z)-1,4diphenylbuta-1,3-diene (CAS no.: 5807-76-1; provider: Chemileva Pharmaceutical); (7Z,3Z)-1,4-di-o-tolylbuta-1,3-diene (CAS no.: 1006055-80-6; provider: Chemileva Pharmaceutical); (7Z,3E)-1,4-diphenylbuta-1,3-diene (CAS no.: 5808-05-9; provider: Chemileva Pharmaceutical); ((7E,3Z)-penta-1,3-diene-1,4-diyl)dibenzene (CAS no.: 40391-41-1; provider: Chemileva Pharmaceutical); ((7Z,3E)-2-methylbuta-1,3-diene-1,4diyl)dibenzene (CAS no.: 83897-70-5; provider: Chemileva Pharmaceutical); 1-methyl-4((7Z,3E)-4-phenylbuta-1,3-dien-1-yl)benzene (CAS no.: 57668-27-6; provider: Chemileva Pharmaceutical); ((2Z,4E)-hexa-2,4-diene-2,5-diyl)dibenzene (CAS no.: 84174-09-4; provider: Chemileva Pharmaceutical); ((7E,3E)-2,3-dimethylbuta-1,3-diene-1,4diyl)dibenzene (CAS no.: 38023-36-8; provider: Chemileva Pharmaceutical); (7E,3E,5E, 7E)-1,8-diphenylocta-1,3,5,7-tetraene (CAS no.: 22828-29-1; provider: Chemileva Pharmaceutical); (7E,3E,5E)-1,6-diphenylhexa-1,3,5-triene (CAS no.: 1732915-6; provider: ASW MedChem); ((7E,3E,5E)-3-methylhexa-1,3,5-triene-1,6diyl)dibenzene (CAS no.: 155337-76-1; provider: Aurora Fine Chemicals LLC); ((7E,3E,5E)-hepta-1,3,5-triene-1,6-diyl)dibenzene (CAS no.: 140654-06-4; provider: Chemileva Pharmaceutical); 1-methyl-4-((7E,3E,5E)-6-phenylhexa-1,3,5-trien-1yl)benzene (CAS no.: 36288-10-5; provider: Chemileva Pharmaceutical); 1-methyl-3-(6phenylhexa-1,3,5-trien-1-yl)benzene (CAS no.: 95278-12-9; provider: Chemileva Pharmaceutical); 1-methyl-2-(6-phenylhexa-1 3,5-trien-1-yl)benzene (CAS no.: 9527813-0; provider: Chemileva Pharmaceutical); 1,6-di-p-tolylhexa-1,3,5-triene (CAS no.: 31382-31-7; provider: Chemileva Pharmaceutical); 3,4-dimethylhexa-1,3,5-triene-1,6diyl)dibenzene (CAS no.: 1295646-09-1; provider: Chemileva Pharmaceutical); 1,3dimethyl-5-(6-phenylhexa-1,3,5-trien-1-yl)benzene (CAS no.: 63296-77-5; provider; Chemileva Pharmaceutical); 1-isopropyl-4-(6-(o-tolyl)hexa-1,3,5-trien-1-yl)benzene (CAS no.: 558453-19-3; provider: Shanghai Chemhere Co.); 2,4-dimethyl-1-(6-phenylhexa1,3,5-trien-1-yl)benzene (CAS no.: 63296-78-6; provider: Chemileva Pharmaceutical); (7Z,3E,5Z)-1,6-diphenylhexa-1,3,5-triene (CAS no.: 170080-16-7; provider: Chemileva

Pharmaceutical); ( 1Z.3Z,5E)A ,6-diphenylhexa-1,3,5-triene (CAS no.: 205808-71-5; provider: Chemileva Pharmaceutical); (7Z,3Z,5Z)-1,6-diphenylhexa-1,3,5-triene (CAS no.: 170080-17-8; provider: Chemileva Pharmaceutical); ((1E,3E,5E)-2,3-dimethylhexa1,3,5-triene-1,6-diyl)dibenzene (CAS no.: 57833-31-5; provider: Chemileva Pharmaceutical); (1E,3E,5E, 7E)A ,8-di-p-tolylocta-1,3,5,7-tetraene (CAS no.: 82720-170; provider: Chemileva Pharmaceutical); 1-methyl-4-(( 1E, 3E, 5E, 7E)-8-phenylocta1,3,5,7-tetraen-1-yl)benzene (CAS no.: 94871-35-9; provider: Chemileva Pharmaceutical); ((1E,3Z,5E, 7E)-2,7-dimethylocta-1,3,5,7-tetraene-1,8-diyl)dibenzene (CAS no.: 82720-21-6; provider: Chemileva Pharmaceutical); (1E,3E,5E,7E,9E)-1,10diphenyldeca-1,3,5,7,9-pentaene (CAS no.: 20576-64-1; provider: Chemileva Pharmaceutical); (3,8-dimethyldeca-1,3,5,7,9-pentaene-1,10-diyl)dibenzene (CAS no.: 1884-48-6; provider: Chemileva Pharmaceutical); and (7E,3E,5E,7E,9E,77E)-1,12diphenyldodeca-1,3,5,7,9,11-hexaene (CAS no.:20576-65-2; provider: Shanghai Chemhere Co.).

The naphthacene dérivative of general formula (VI) is preferably characterized by a boiling point lower than about 650 °C at 760 mm Hg. Examples of naphthacene dérivative of general formula (VI), include, but are not limited to: 1,11-diphenyl-naphthacene (CAS no.: 927669-50-9; provider: Advanced Organic Synthesis); 5,12-diphenyl-naphthacene (CAS no.: 27130-32-1; provider: Chemieliva Pharmaceutical Co); 5,6,11,12-tetraphenylnaphthacene (CAS no.: 517-51-1; provider: Chemieliva Pharmaceutical Co); and 5,12bis[4-(1,1-dimethyle1:hyl)phenyl]-naphthacene (CAS no.: 478799-46-1; provider: Chemieliva Pharmaceutical Co).

The aromatic compound substituted by at least one group selected from Ci-C4-alkyloxy may be further substituted by one or more substituents selected from Ci-C4-alkyl and is preferably characterized by a boiling point lower than about 600 °C at 760 mm Hg, more preferably lower than 500 °C at 760 mm Hg, and even more preferably lower than 450 °C at 760 mm Hg. Examples of aromatic compounds substituted by at least one group selected from Ci-C4-alkyloxy include, but are not limited to: 1,4dimethoxybenzene (CAS no.: 150-78-7; provider: abcr GmbH); 1,4-diethoxybenzene (CAS no.: 122-95-2; provider: abcr GmbH); 1,4-bis(1-methylethoxy)benzene (CAS no.: 7495-78-5; provider: Chemieliva Pharmaceutical); 1,4-dimethoxy-2-methylbenzene (CAS no.: 24599-58-4; provider: Alchem Pharmtech); 1,4-dimethoxy-2,5-dimethyl-benzene (CAS no.: 2674-32-0; provider: Chemieliva Pharmaceutical Co.); 1,4-dimethoxy-2,3dimethylbenzene (CAS no.: 39021-83-5; provider: Chemieliva Pharmaceutical Co.); 1,4diethoxy-2-methylbenzene (CAS no.: 41901-72-8; provider: Chemieliva Pharmaceutical

Co.); 1,4-dibutoxy-benzene (CAS no.: 104-36-9; provider: Chemieliva Pharmaceutical Co.); 1,3-dimethoxybenzene (CAS no.: 151-10-0; provider: Alchem Pharmtech); 1,3diethoxybenzene (CAS no.: 2049-73-2; provider: Chemieliva Pharmaceutical Co.); 1,3dimethoxy-5-methyl-benzene (CAS no.: 4179-19-5; provider: ASW MedChem); 1,3,5trimethoxybenzene (CAS no.: 621-23-8; provider: AK Scientific); 1,3,5-triethoxybenzene (CAS no.: 2437-88-9; provider: Chemieliva Pharmaceutical); 1,3-dimethoxy-5-(1methylethoxy)benzene (CAS no.: 86635-94-1: provider: Chemieliva Pharmaceutical); 2ethoxy-1,3,5-trimethoxybenzene (CAS no.: 69832-53-7; provider: Chemieliva Pharmaceutical); 1,3,5-trimethoxy-2,4,6-trimethylbenzene (CAS no.: 1521-62-6; provider: Chemieliva Pharmaceutical); 1,3-dimethoxy-2-methyl-5-(1-methylethoxy)-benzene (CAS no.: 93680-97-8; provider: Chemieliva Pharmaceutical); 1,3-dibutoxy-5-methoxy-benzene (CAS no.: 869740-90-9; provider: Chemieliva Pharmaceutical); 1,2,3,4,5,6hexamethoxybenzene (CAS no.: 22015-34-5; provider: Chemieliva Pharmaceutical); 4methoxy-1 ,Τ-biphenyl (CAS no.: 613-37-6; provider: ASW MedChem); 4-methoxy-4'methyl-1 ,Τ-biphenyl (CAS no.: 53040-92-9; provider: ASW MedChem); 4-ethoxy-biphenyl (CAS no.: 613-40-1; provider: Chemieliva Pharmaceutical);2-methyl-9,10dimethoxyanthracene (CAS no.: 26708-05-4; provider: Chemieliva Pharmaceutical Co.); 2-ethyl-9,10-dimethoxyanthracene (CAS no.: 26708-04-3; provider: Aldrich); 2-(1,1dimethyl-ethyl)-9,10-dimethoxyanthracene (CAS no.: 62770-63-2; provider: Chemieliva Pharmaceutical Co.); 2-ethyl-9,10-diethoxyanthracene (CAS no.: 205515-07-7; provider: Chemieliva Pharmaceutical Co.); 9,10-dimethoxyanthracene (CAS no.: 2395-97-3; provider: Chemieliva Pharmaceutical Co.); 9,10-diethoxyanthracene (CAS no.: 68818-860; provider: ASW MledChem); 9,10-bis(1-methylethoxy)-anthracene (CAS no.: 13476744-5; provider: Chemieliva Pharmaceutical Co.); 9,10-bis(1,1-dimethylethoxy)-anthracene (CAS no.: 873914-42-2; provider: Shanghai Chemhere Co.); 9,10-dibutoxy-anthracene (CAS no.: 76275-14-4; provider: Chemieliva Pharmaceutical Co.); 9-ethoxy-10-methoxyanthracene (CAS no.: 106500-38-3; provider: Chemieliva Pharmaceutical Co.); 9,10dimethoxy-1,4,5,8-tetramethyl-anthracene (CAS no.: 76466-58-5; provider: Chemieliva Pharmaceutical Co.); 9,10-dimethoxy-1,2,3,4,5,6,7,8-octamethyl-anthracene (CAS no.: 75670-41-6; provider: Chemieliva Pharmaceutical Co.); 9,10-dimethoxy-1,2,3,4tetramethyl-anthracene (CAS no.: 72049-50-4; provider: Chemieliva Pharmaceutical Co.); 2,6-dimethyl-9,10-dimethoxyanthacene (CAS no.: 1221786-94-2; provider: Rare Chemicals GmbH); 1,2-dimethoxy-anthracene (CAS no.: 132814-35-8; provider: Shanghai Chemhere Co.); 1,3-dimethoxyanthracene (CAS no.: 144493-74-3; provider: Chemieliva Pharmaceutical Co.); 1,4-dimethoxy-9-ethyl-anthracene (CAS no.: 10732877-8; provider: Chemieliva Pharmaceutical Co.); 1,4-diethoxy-anthracene (CAS no.:

75830-00-1; provider: Chemieliva Pharmaceutical Co.); 1,5-dimethoxy-anthracene (CAS no.: 16294-32-9; provider: Chemieliva Pharmaceutical Co.); 1,5-diethoxy-anthracene (CAS no.: 75829-95-7; provider: Chemieliva Pharmaceutical Co.); 1,8-dimethoxyanthracene (CAS no.: 16294-34-1; provider: Chemieliva Pharmaceutical Co.); 1,8diethoxy-anthracene (CAS no.: 75829-96-8; provider: Chemieliva Pharmaceutical Co.); 1,8-dimethoxy-3-methyl-anthracene (CAS no.: 144493-77-6; provider: Chemieliva Pharmaceutical Co.); 1,8-dimethoxy-2,7-dimethyl-anthracene (CAS no.: 1202400-23-4; provider: Chemieliva Pharmaceutical Co.); 2,3-dimethoxy-anthracene (CAS no.: 5179019-3; provider: Chemieliva Pharmaceutical Co.); 2,3-diethoxy-anthracene (CAS no.: 863889-35-4; provider: Chemieliva Pharmaceutical Co.); 2,6-dimethoxy-anthracene (CAS no.: 36319-03-6; provider: Chemieliva Pharmaceutical Co.); 2,6-diethoxy-anthracene (CAS no.: 75830-05-6; provider: Chemieliva Pharmaceutical Co.); 2,6-dimethoxy-9methyl-anthracene (CAS no.: 110038-59-0; provider: Chemieliva Pharmaceutical Co.); 2,6-dimethoxy-9,10-dimethyl-anthracene (CAS no.: 105858-59-1; provider: Chemieliva Pharmaceutical Co.); 2,6-dipropoxy-anthraœne (CAS no.: 1395499-89-4; provider: Chemieliva Pharmaceutical Co.); 2,6-dibutoxy-anthracene (CAS no.: 134277-70-6; provider: Chemieliva Pharmaceutical Co.); and 2,7-dimethoxy-anthracene (CAS no.: 55360-36-6; provider: Chemieliva Pharmaceutical Co.).

EXAMPLES

The présent invention is now described in greater detail with respect to non-limiting examples.

General

Ail Chemicals were purchased from Sigma Aldrich and were used without further purification. The marker N¹, N¹, N⁵, A/⁵-tetraethyl-naphthalene-1,5-diamine was prepared according to the description here below. Pre-cut Silica gel 60 F254 TLC plates from Merck KGaA were used for TLC. Silica gel 60 (0.04-0.063 mm) purchased from Cari Roth GmbH & CO.KG was used for flash chromatography. Ail NMR spectra were measured on a Bruker Avance 300 MHz Spectrometer. The resulting reported Chemical shifts (δ; in ppm) are referred the chloroform (δ = 7.26 ppm) for ¹H NMR and (δ = 77.23 ppm) for ¹³C NMR. The Chemical marker /V,/V-dimethylnaphthalen-1-amine (CAS no.: 86-56-6, >98%) was purchased from Sigma Aldrich and used without further purification.

Synthesis of the marker N¹, N¹, N⁵, A/⁵-tetraethyl-naphthalene-1,5-diamine (CAS no.: 861347-34-4)

N¹, N¹, N⁵, /V^etraethyl-nsphthalene-l ,5-diamine

In a three neck flask 1,5-diaminonaphthalene (1 equiv., 10 mmol, 1.59 g) (CAS no.: 224362-1, Sigma Aldrich, 97%) and ethyl bromide (8 equiv., 80 mmol, 8.72 g, 5.92 ml) (CAS no.: 74-96-4, Sigma Aldrich, 98%) were dissolved in acetonitrile (75 mL) under Ar. N,Ndiisopropylethylamine (8 equiv., 80 mmol, 10.32 g, 13.57 mL) (CAS no.: 7087-68-5, Sigma Aldrich, >99%) was added dropwise at room température, the solution was stirred vigorously under reflux for 12 h. The reaction mixture was cooled to room température and extracted with toluene and water. After évaporation of the solvent, the mixture was purified by liquid chromatography yielding N¹, N¹, N⁵, /V⁵-tetraethyl-naphthalene-1,5diamine (0.73 g) (rf = 0.95 in hexanes/ethyl acetate = 10:1) was obtained with a yield of 27 % as a colourless solid.

¹H NMR (300 MHz, CDCI3) δ = 8.05 (d, J = 7.33 Hz, 2 H), 7.39 (dd, J = 7.33, 8.1 Hz, 2 H), 7.10 (d, J = 8.10 Hz, 2 H), 3.20 (q, J = 7.10 Hz, 8 H), 1.07 (t, J = 7.1 Hz, 12 H); ¹³C NMR (300 MHz, CDCI3) δ = 148.33, 132.84, 124.67, 119.69, 117.84, 47.87, 12. 54; MS (ESI) m/z = 271.2174 (M+H)⁺ (calcd. for Ci8H₂7N₂: 271.2174); IR (film): 3044 (m), 2968 (s), 1983 (w), 1858 (w), 1585 (S), 783 (s).

I. APPARATUS and ANALYTICAL METHOD

Two different, but comparable set-ups were built: the first one described at item La below was used for conducting laser ionization - mass spectrometry measurements and the second one described at item l.b below was used for conducting laser ionization - ion mobility spectrometry measurements. In both set-ups, an optical parametric oscillator (OPO) pumped by a Nd:YAG laser (NT342A-SH, Ekspla) was used for samples ionization.

La Description instrument and method for analysis by laser ionization - mass spectrometry.

The set-up used for conducting the laser ionization - mass spectrometry analysis contains a thermal desorption unit (Thermo desorberTC-13.006 from PAS Technology), an optical parametric oscillator (OPO) pumped by a Nd:YAG laser (NT342A-SH, Ekspla), and a commercial mass spectrometer (LTQ XL™, Thermo Fisher Scientific) equipped with a self-made ion source (J. Mass Spectrom. (2016), 51,566-577) having two quartz Windows transparent to a laser beam. The thermal desorption unit is connected via a métal capillary (stainless Steel tubing 1/8 outer diameter x 2.0 mm inner diameter, about 60 mm long from Ziemer Chromatographie) to the ion source of the mass spectrometer.

The compositions of petroleum hydrocarbon were analyzed by the following method: 2pL of the liquid sample were introduced using a syringe (Hamilton, 10 pL) into the thermal desorption unit heated to 250 °C. Following vaporization, the gaseous sample was transferred via the métal capillary heated to 200 °C (about 60 mm long) using a N₂ flow (600 mL/min) in the ionization chamber heated to 120 °C (about 18 mm long, inner diameter of 20 mm) of the ion source, where the gaseous sample was subjected to laser ionization. The ionized sample was then transferred into the MS spectrometer (N₂ flow: 1000 mL/min; V: 50 Volts) and the MS spectrum was measured in relative intensifies as a function of mass - to - charge ratio (m/z).

I.b Description instrument and method for analysis by laser ionization - ion mobility spectrometry.

The set-up used for conducting the laser ionization - ion mobility spectrometry analysis contains an injector of a commercial gas chromatograph (HP 5890 SU, Hewlett Packard, now: Agilent) used only for sample vaporization, a self-made ion mobility spectrometer (Anal. Bional. Chem. 405, 7019) having quartz Windows transparent to a laser beam and an optical parametric oscillator (OPO) pumped by a Nd:YAG laser (NT342A-SH, Ekspla). The injector of the gas chromatograph is connected via a capillary (deactivated fused silica capillary, 0.18 mm inner diameter, 400 mm long from Perkin Elmer) to the ion source of the ion mobility spectrometer. The drift tube of the ion mobility spectrometer is 100 mm long and has an inner diameter of 25 mm. The ion currents on the Faraday plate are amplified (1 GV/A amplifier, ISAS Dortmund) and recorded on a USB oscilloscope (Handyscope HS3, 5 MHz, Tiepie Engineering).

The compositions of petroleum hydrocarbon were analyzed by the following method: 2 pL of the liquid sample were introduced using a syringe (Hamilton, 10 pL) into an injector (inlet gas: N₂; flow inlet gas: 200 mL/min) heated to 250 °C of the commercial gas chromatograph. Following vaporization, the gaseous sample was transferred using a N₂flow of 15 mL/min via the uncoated métal capillary heated to 200 °C (400 mm long) into the ionization chamber heated to 180 °C (about 18 mm long, inner diameter of 20 mm) of the ion mobility spectrometer, where the gaseous sample was subjected to laser ionization. The ionized sample entered the heated drift tube (150 °C) of the ion mobility spectrometer. Nitrogen (flow: 200 mL/min; drift tube voltage: 4.5 kV) or hélium (flow: 200 mL/min; drift tube voltage: 2.5 kV) was used as drift gas. The ion currents on the Faraday plate were amplified (1 GV/A amplifier, ISAS Dortmund) and recorded on a USB oscilloscope (Handyscope HS3, 5 MHz, Tiepie Engineering).

II. Préparation of marked Petroleum hydrocarbons

For petroleum hydrocarbon marking, a concentrate of N¹, N¹, N⁵, A/⁵-tetraethylnaphthalene-1,5-diamine in hexane was prepared to a concentration of 5 mmol/L and added to gasoline, diesel or hexane to yield a marked gasoline sample, a marked diesel sample and a marked hexane sample, respedtively.

Further, a concentrate of /V,/V-dimethylnaphthalen-1 -amine in hexane was prepared to a concentration of 10 mmol/L and added to gasoline or diesel to yield a marked gasoline sample (Chemical marker concentration: 10 μΜ) and a marked diesel sample (Chemical marker concentration: 10 μΜ).

To avoid contamination, prior to analysis, the marked gasoline sample and the marked diesel sample were diluted in hexane (1 : 100; v / v).

Results

The composition of diesel containing the Chemical marker N¹, N¹, N⁵, A/⁵-tetraethylnaphthalene-1,5-diamine prepared as described at item II above was analyzed by laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled to mass spectrometry (see Fig. 1a and Fig. 1c) using the instrument and following the procedure described at item La above, as well as by laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled to ion mobility spectrometry (see Fig. 2c) using the instrument and following the procedure described at item l.b above.

The composition of gasoline containing the Chemical marker N¹, N¹, N⁵, A/⁵-tetraethylnaphthalene-1,5-diamine prepared as described at item II above was analyzed by laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled to mass spectrometry (see Fig. 1b) using the instrument and following the procedure described at item La above, as well as by laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled to ion mobility spectrometry (see Fig. 2c) using the instrument and following the procedure described at item l.b above.

The composition of hexane containing the Chemical marker N¹, N¹, N⁵, A/⁵-tetraethylnaphthalene-1,5-diamine prepared as described at item II above was analyzed by laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled to mass spectrometry (see Fig. 1c) using the instrument and following the procedure described at item l.a above, as well as by laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled to ion mobility spectrometry (see Fig. 2a - Fig. 2c) using the instrument and following the procedure described at item l.b above. A composition of gasoline in hexane (1:100, v / v) and a composition of diesel in hexane (1:100, v / v) were also analyzed by laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled with ion mobility spectrometry using the instrument and following the procedure described at item l.b above.

The composition of diesel and the composition of gasoline containing the Chemical marker A/,A/-dimethylnaphthalen-1 -amine prepared as described at item II above were analyzed by laser ionization at 308 nm (puise energy density of 0.30 mJ/mm²) coupled to mass spectrometry (see Fig. 3a and Fig. 3b, respectively) using the instrument and following the procedure described at item l.a above.

Fig. 1a illustrâtes the mass spectrum of a composition of diesel containing the Chemical marker N¹, N¹, N⁵, /V⁵-tetraethyl-naphthalene-1,5-diamine obtained by laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled with mass spectrometry. To minimize the contamination of the mass spectrometer, the composition of diesel containing the Chemical marker was diluted in hexane (1 : 100; v / v) priorto the analysis. Following dilution, the concentration of the Chemical marker in the sample was of 50 nM. The peak corresponding to the ion (M⁺) of the Chemical marker (m/z of 270) is indicated by a “*”. As attested by the mass spectrum, the Chemical marker N¹, N¹, N⁵, /\/⁵-tetraethylnaphthalene-1,5-diamine can be easily detected and identified even at low concentration in a diesel matrix because it exhibits the highest intensity in the mass spectrum, thereby enabling the easy authentication of a diesel marked with said marker. These surprising results are due to the sélective ionization of the Chemical marker N¹, N¹, N⁵, /V⁵-tetraethylnaphthalene-1,5-diamine in a composition of diesel upon illumination with pulsed laser light of a wavelength of 355 nm (puise energy density of 0.63 mJ/mm²). The poor ionization of the diesel matrix upon illumination with pulsed laser light of a wavelength of

355 nm leads to a negligible noise in the mass spectrum that does not interfère with the détection of the Chemical marker.

Fig. 1 b illustrâtes the mass spectrum of a composition of gasoline containing the Chemical marker N¹, N¹, N⁵, /Atetraethyl-naphthalene-t ,5-diamine obtained by laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled with mass spectrometry. To minimize the contamination of the mass spectrometer, the composition of gasoline containing the Chemical marker was diluted in hexane to (1 : 100; v / v) prior to the analysis. Following dilution, the concentration of the Chemical marker N¹, N¹, N⁵, N⁵tetraethyl-naphthalene-1,5-diamine in the sample was of 50 nM. The peak corresponding to the ion (M⁺) of the Chemical marker (m/z of 270) is indicated by a As attested by the mass spectrum, the Chemical marker N¹, N¹, N⁵, A/⁵-tetraethyl-naphthalene-1,5-diamine can be easily detected and identified even at low concentration in a gasoline matrix because it exhibits the highest intensity peak in the mass spectrometry, thereby enabling the easy authentication of a gasoline marked with said marker. These surprising results are due to the sélective ionization of the Chemical marker N¹, N¹, N⁵, /\/⁵-tetraethylnaphthalene-1,5-diamine in a composition of gasoline upon illumination with pulsed laser light of a wavelength of 355 nm (puise energy density of 0.63 mJ/mm²). The poor ionization of the gasoline matrix upon illumination with pulsed laser light of a wavelength of 355 nm leads to a negligible noise in the mass spectrum that does not interfère with the détection of the Chemical marker.

Fig. 1c illustrâtes the variation of the intensity of the peak corresponding to the molecular ion (M⁺) ofthe Chemical marker N¹, N¹, N⁵, /V⁵-tetraethyl-naphthalene-1,5-diamine with the concentration of the Chemical marker in a composition of diesel and a composition of hexane. The compositions of diesel and hexane containing the Chemical marker N¹, N¹, N⁵, A/⁵-tetraethyl-naphthalene-1,5-diamine were analyzed by laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled to mass spectrometry. To minimize the contamination of the mass spectrometer, the compositions of diesel containing the Chemical marker were diluted in hexane (1 : 100; v / v) prior to the analysis. The perfect linearity ofthe calibration curve proves that the Chemical marker N¹, N¹, N⁵, /\/⁵-tetraethylnaphthalene-1,5-diamine is easily détectable, identifiable and quantifiable in a diesel composition even at low concentration of 1 μΜ by combining laser sélective ionization at 355 nm (puise energy density of 0.63 mJ/mm²) with mass spectrometry. Further, the overlapping ofthe two calibration curves prove the low matrix effect ofthe diesel.

Fig. 2a illustrâtes the superimposed ion mobility spectra of a composition of hexane containing the Chemical marker N¹, N¹, N⁵, A/⁵-tetraethyl-naphthalene-1,5-diamine at a concentration of 2 μΜ (black colored spectrum) and of an unmarked diesel (grey colored spectrum) obtained by laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled with ion mobility spectrometry (drift gas: hélium; flow: 200 ml/min; drift tube voltage: 2.5 kV). To minimize the contamination of the spectrometer, the composition of unmarked diesel was diluted in hexane (1 : 100; v / v) prior to the analysis. The Chemical marker N¹, N¹, N⁵, A/⁵-tetraethyl-naphthalene-1,5-diamine is characterized by a drift time of about 7.4 ms. As attested by Fig. 2a, as diesel generates a negligible noise when subjected to laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled with ion mobility spectrometry that does not mask the peak corresponding to the Chemical marker N¹, N¹, N⁵, /V⁵-tetraethylnaphthalene-1,5-diamine, said Chemical marker can be easily detected and identified in a composition of diesel, and therefore can be used for diesel marking to prevent counterfeiting of said diesel.

Fig. 2b illustrâtes the superimposed ion mobility spectra of a composition of hexane containing the Chemical marker N¹, N¹, N⁵, A/⁵-tetraethyl-naphthalene-1,5-diamine at a concentration of 2 μΜ (black colored spectrum) and of an unmarked gasoline (grey colored spectrum) obtained by laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled with ion mobility spectrometry (drift gas: hélium; flow: 200 ml/min; drift tube voltage: 2.5 kV). To minimize the contamination of the spectrometer, the composition of unmarked gasoline was diluted in hexane (1 : 100; v / v) prior to the analysis. The Chemical marker N¹, N¹, N⁵, /V⁵-tetraethyl-naphthalene-1,5-diamine is characterized by a drift time of about 7.4 ms. As attested by Fig. 2b, as gasoline generates a negligible noise when subjected to laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled with ion mobility spectrometry that does not mask the peak corresponding to the Chemical marker N¹, N¹, N⁵, A/⁵-tetraethylnaphthalene-1,5-diamine, said Chemical marker can be easily detected and identified in a composition of gasoline, and therefore can be used for gasoline marking to prevent counterfeiting of said gasoline.

Fig. 2c illustrâtes the variation of the intensity of the peak corresponding to the ion (M⁺) of the Chemical marker N¹, N¹, N⁵, A/⁵-tetraethyl-naphthalene-1,5-diamine with the marker concentration in a composition of diesel, a composition of gasoline and a composition of hexane. The compositions of diesel, gasoline and hexane containing the Chemical marker

N¹, N¹, N⁵, /V⁵-tetraethyl-naphthalene-1,5-diamine were analyzed by laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²) coupled with ion mobility spectrometry (drift gas: hélium; flow: 200 ml/min; drift tube voltage: 2.5kV). Prior to the analysis, the composition of diesel containing the Chemical marker and the composition of gasoline containing the Chemical marker were diluted in hexane (1 : 100; v / v) to minimize the contamination of the spectrometer. The perfect linearity and the overlapping of the three calibration curves prove that N¹, N¹, N⁵, /V⁵-tetraethyl-naphthalene-1,5-diamine is suitable for marking a variety of petroleum hydrocarbons, including diesel and gasoline. The Chemical marker N¹, N¹, N⁵, A/⁵-tetraethyl-naphthalene-1,5-diamine has the advantage of being selectively ionized upon laser ionization at 355 nm (puise energy density of 0.63 mJ/mm²). Thus, even low concentrations of 1 μΜ of said Chemical marker are détectable, identifiable and quantifiable in complex petroleum hydrocarbons by combining laser sélective ionization at 355 nm with ion mobility spectrometry.

Fig. 3a illustrâtes the mass spectrum of a composition of diesel containing the Chemical marker A/,A/-dimethylnaphthalen-1 -amine obtained by laser ionization at 308 nm (puise energy density of 0.30 mJ/mm²) coupled with mass spectrometry. To minimize the contamination of the mass spectrometer, the composition of diesel containing the Chemical marker was diluted in hexane (1 : 100; v / v) prior to the analysis. Following dilution, the concentration of the Chemical marker in the sample analyzed by laser ionization at 308 nm (puise energy density of 0.30 mJ/mm²) coupled with mass spectrometry was of 10 pM. The peak corresponding to the ion (M⁺) of the Chemical marker (m/z of 171) is indicated by a As attested by the mass spectrum, the Chemical marker A/,A/-dimethylnaphthalen-1 -amine can be easily detected and identified even at low concentration in a diesel matrix because it exhibits the highest intensity in the mass spectrum, thereby enabling the easy authentication of a diesel marked with said marker. These surprising results are due to the sélective ionization of the Chemical marker N,Ndimethylnaphthalen-1-amine in a composition of diesel upon illumination with pulsed laser light of a wavelength of 308 nm (puise energy density of 0.30 mJ/mm²). The poor ionization of the diesel matrix upon illumination with pulsed laser light of a wavelength of 308 nm leads to a negligible noise in the mass spectrum that does not interfère with the détection of the Chemical marker.

Fig. 3b illustrâtes the mass spectrum of a composition of gasoline containing the Chemical marker A/,/\/-dimethylnaphthalen-1 -amine obtained by laser ionization at 308 nm (puise energy density of 0.30 mJ/mm²) coupled with mass spectrometry. To minimize the contamination of the mass spectrometer, the composition of diesel containing the Chemical marker was diluted in hexane (1 : 100; v / v) prior to the analysis. Following dilution, the concentration of the Chemical marker in the sample analyzed by laser ionization at 308 nm (puise energy density of 0.30 mJ/mm²) coupled with mass 5 spectrometry was of 10 μΜ. The peak corresponding to the ion (M⁺) of the Chemical marker (m/z of 171) is indicated by a As attested by the mass spectrum, the Chemical marker /V,/V-dimethylnaphthalen-1-amine can be easily detected and identified even at low concentration in a gasoline matrix because it exhibits the highest intensity in the mass spectrum, thereby enabling the easy authentication of a gasoline marked with said marker.

These surprising results are due to the sélective ionization of the Chemical marker N,Ndimethylnaphthalen-1-amine in a composition of gasoline upon illumination with pulsed laser light of a wavelength of 308 nm (puise energy density of 0.30 mJ/mm²). The poor ionization of the gasoline matrix upon illumination with pulsed laser light of a wavelength of 308 nm leads to a negligible noise in the mass spectrum that does not interfère with the 15 détection of the Chemical marker.

Claims

1. A composition of a petroleum hydrocarbon comprising:

the residues R¹ - R⁶ are independently of each other selected from the group consisting of hydrogen, Ci-Ce-alkyl and NR^eR^f;

the substituents R^c and R^d are independently of each other selected from Ci-Ce-alkyl, or alternatively the substituents R^c and R^d taken together form a residue -(CH2)m-, wherein m is an integer from 2 to 5; and the substituents R^e and R^f are independently of each other selected from Ci-Ce-alkyl, or alternatively the substituents R^e and R^f taken together form a residue -(CH₂)_P-, wherein p is an integer from 2 to 5.

2. The composition according to claim 1, wherein the at least one Chemical marker of general formula (I) has a concentration of at least 1 μΜ.

3. The composition according to claim 1 or 2, wherein the at least one Chemical marker is of general formula (II),

the residues R¹ - R^G are independently of each other selected from the group consisting of hydrogen and C-i-Ce alkyl;

the residue R⁷ has the meaning as defined in claim 1; and the substituents R^a -- R^d hâve the meanings as defined in claim 1.

4. The composition according to claim 1 or 2, wherein the at least one Chemical marker is of general formula (III)

wherein the residue R² represents NR^eR^f, the residues R¹, R³ - R⁶ are independently of each other selected from the group consisting of hydrogen and Ci-Cs alkyl, the substituents R^a, R^b, R® and R^f hâve the meanings as defined in claim 1 and the residue R⁷ has the meaning as defined in claim 1 ;

or the residue R³ represents NR^eR^f, the residues R¹, R², R⁴ - R⁶ are independently of each other selected from the group consisting of hydrogen and Ci-Ce-alkyl, the substituents R^a, R^b, R^e and R^f hâve the meanings as defined in claim 1 and the residue R⁷ has the meaning as defined in claim 1 ;

or the residue R⁶ represents NR^eR^f, the residues R¹ - R⁵ are independently of each other selected from the group consisting of hydrogen and Ci-Ce-alkyl, the substituents R^a, R^b,

R® and R^f hâve the meanings as defined in claim 1 and the residue R⁷ has the meaning as defined in claim 1.

5. The composition according to claim 1 or 2, wherein the at least one Chemical marker is of general formula (IV)

wherein the residues R¹ - R⁶ are independently of each other selected from the group consisting of hydrogen and C-i-Ce alkyl;

the substituents R^a and R^b hâve the meanings as defined in claim 1 and the residue R⁷has the meaning as defined in claim 1;

or the residue R¹ represents NR^eR^f, the residues R² - R⁶ are independently of each other selected from the group consisting of hydrogen and Ci-Ce alkyl, the substituents R^a, R^b, R® and R^f hâve the meanings as defined in claim 1 and the residue R⁷ has the meanings as defined in claim 1 ;

or the residue R⁴ represents NR^eR^f, the residues R¹ - R³, R⁵ and R⁶ are independently of each other selected from the group consisting of hydrogen and Οι-Ce alkyl, the substituents R^a, R^b, R® and R^f hâve the meanings as defined in claim 1 and the residue R⁷ has the meaning as defined in claim 1 ;

or the residue R⁵ represents NR^eR^f, the residues R¹ - R⁴ and R⁶ are selected from the group consisting of hydrogen and Ci-Ce alkyl, the substituents R^a, R^b, R® and R^f hâve the meanings as defined in claim 1 and the residue R⁷ has the meaning as defined in claim 1.

6. The composition according to any one of the claims 1 - 5, wherein the residues R¹- R⁶ other than NR^eR^f represent hydrogen.

7. The composition according to any one of the claims 1 - 6, wherein the residue R⁷ represents hydrogen.

8. The composition according to any one of the daims 1 - 7, wherein the petroleum hydrocarbon is selected from the group consisting of: crude oil, lubricating oil, brake fluid, gasoline, diesel fuel, kerosene, jet fuel, heating oil and heavy fuel oil.

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9. A method for marking a petroleum hydrocarbon, wherein said method comprises adding to and uniformly mixing with said petroleum hydrocarbon the at least one Chemical marker as defined in any one of the daims 1 and 3-7.

10. The method according to daim 9, wherein the petroleum hydrocarbon is selected from the group consisting of: crude oil, lubricating oil, brake fluid, gasoline, diesel fuel, 10 kerosene, jet fuel, heating oil and heavy fuel oil.