Abstract: The present invention is a method of making 1,4,5,8-tetrakis(R-phenylamino)anthracene-9,10-dione (where R is H or a hydrocarbyl group) comprising the step of contacting 1,4,5,8-tetrachloroanthraquinone with a mixture of R-anilines comprising at least two different R groups, under conditions to produce 1,4,5,8-tetrakis(R-phenylamino)anthracene-9,10-dione. The present disclosure also provides a reaction mixture of 1,4,5,8-tetrakis(R-phenylamino)anthracene-9,10-dione characterized by having the R groups on at least 75% of the 1,4,5,8-tetrakis(R-amino)anthracene-9,10-dione molecules in the mixture be comprised of 2 or more different R groups.

Abstract: 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 R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10-substituted diaryl ether, wherein R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 independently are hydrogen, hydrocarbyl or hydrocarbyloxy; wherein each compound having formula (I) is present at a level from 0.01 ppm to 20 ppm.

Abstract: 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 R1, R2, R3, R4, R5, R6, R7 and R8—substituted dibenzofuran, wherein R1, R2, R3, R4, R5, R6, R7 and R8 independently are hydrogen, hydrocarbyl, hydrocarbyloxy, aryl or aryloxy; provided that R1, R2, R3, R4, R5, R6, R7 and R8 collectively have at least two carbon atoms; wherein each compound having formula (I) is present at a level from 0.01 ppm to 20 ppm.

Abstract: 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 R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10-substituted xanthene, wherein R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 independently are hydrogen, hydrocarbyl, hydrocarbyloxy, aryl or aryloxy; wherein each compound of formula (I) is present at a level from 0.01 ppm to 20 ppm.

Abstract: 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 R1, R2, R3, R4, R5, R6, R7 and R8—substituted dibenzofuran, wherein R1, R2, R3, R4, R5, R6, R7 and R8 independently are hydrogen, hydrocarbyl, hydrocarbyloxy, aryl or aryloxy; provided that R1, R2, R3, R4, R5, R6, R7 and R8 collectively have at least two carbon atoms; wherein each compound having formula (I) is present at a level from 0.01 ppm to 20 ppm.

Abstract: 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 R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10-substituted diaryl ether, wherein R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 independently are hydrogen, hydrocarbyl or hydrocarbyloxy; wherein each compound having formula (I) is present at a level from 0.01 ppm to 20 ppm.

Abstract: 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 R1, R2, R3, R4, R5, R6, R7 , R8, R9 and R10-substituted xanthene, wherein R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 independently are hydrogen, hydrocarbyl, hydrocarbyloxy, aryl or aryloxy; wherein each compound of formula (I) is present at a level from 0.01 ppm to 20 ppm.

Abstract: A compound having formula C{Ph(R1)i(OR2)j}2{Ph(R3)m(OR4)n}{Ph(R5)o(OR6)p}, wherein Ph represents a benzene ring, R1, R3 and R5 independently are C1-C18 alkyl; R2, R4 and R6 independently are C4-C12 alkyl, i, m, n, o, and p independently are zero, one or two; j is one or two.

Abstract: A method for marking a petroleum hydrocarbon or a liquid biologically derived fuel by adding to the petroleum hydrocarbon or liquid biologically derived fuel a compound having formula C{Ph(R1)i(OR2)j}2{Ph(R3)m(OR4)n}{Ph(R5)o(OR6)p}, wherein Ph represents a benzene ring, R1, R3 and R5 independently are C1-C18 alkyl or C4-C18 heteroalkyl; R2, R4 and R6 independently are C1-C18 alkyl or C4-C18 heteroalkyl, i, j, m, n, o and p independently are zero, one or two. Each compound having formula C{Ph(R1)i(OR2)j}2{Ph(R3)m(OR4)n}{Ph(R5)o(OR6)p} is present at a level from 0.01 ppm to 20 ppm.

Abstract: A gas chromatographic method for detecting a marker compound in a fuel by (a) introducing a sample of fuel into a first capillary column coated with a stationary phase based on polydimethylsiloxane and allowing the sample to flow through the first column to produce a first effluent; (b) allowing the first effluent to pass through a detector and identifying a retention time range in it which includes a retention time of the marker compound; (c) introducing only a portion of the first effluent stream which is within the retention time range into a second capillary column coated with either (i) an ionic sorbent or (ii) a polyethylene glycol, and allowing said portion to flow through the second capillary column to produce a second effluent stream; and (d) allowing the second effluent to pass through a detector; wherein the marker compound has formula Ar(R2)m(OR1)n and is present in the fuel at a level from 0.01 ppm to 100 ppm.

Abstract: A gas chromatographic method for detecting a first marker and a second marker in a fuel in two channels: (i) a first capillary column coated with polysiloxane and a second capillary column coated with polyethylene glycol; and (ii) a third capillary column coated with polymethylphenylsiloxane and a fourth deactivated capillary column. The steps are: (a) introducing a first sample into the first column to produce a first effluent; (b) introducing only a portion of the first effluent into the second column to produce a second effluent; (c) allowing the second effluent to pass through a mass spectrometer; (d) introducing a second sample into the third column to produce a third effluent; (e) introducing only a portion of the third effluent into the fourth column to produce a fourth effluent; (f) allowing the fourth effluent to pass through a mass spectrometer.

Abstract: A compound having formula C{Ph(R1)i(OR2)j}2{Ph(R3)m(OR4)n}{Ph(R5)o(OR6)p}, wherein Ph represents a benzene ring, R1, R3 and R5 independently are C1-C18 alkyl or C4-C18 heteroalkyl; R2, R4 and R6 independently are C1-C18 alkyl or C4-C18 heteroalkyl, i, j, m, n, o and p independently are zero, one or two.

Abstract: A method for marking a petroleum hydrocarbon or a liquid biologically derived fuel by adding to the petroleum hydrocarbon or liquid biologically derived fuel a compound having formula C{Ph(R1)i(OR2)j}2{Ph(R3)m}{OR4)n}{Ph(R5)o(OR6)p}, wherein Ph represents a benzene ring, R1, R3 and R5 independently are C1-C18 alkyl or C4-C18 heteroalkyl; R2, R4 and R6 independently are C1-C18 alkyl or C4-C18 heteroalkyl, i, j, m, n, o and p independently are zero, one or two. Each compound having formula C{Ph(R1)i(OR2)j}2{Ph(R3)m(OR4)n}{Ph(R5)o(0R6)p} is present at a level from 0.01 ppm to 20 ppm.

Abstract: A gas chromatographic method for detecting a first marker and a second marker in a fuel in two channels: (i) a first capillary column coated with polysiloxane and a second capillary column coated with polyethylene glycol; and (ii) a third capillary column coated with polymethylphenylsiloxane and a fourth deactivated capillary column. The steps are: (a) introducing a first sample into the first column to produce a first effluent; (b) introducing only a portion of the first effluent into the second column to produce a second effluent; (c) allowing the second effluent to pass through a mass spectrometer; (d) introducing a second sample into the third column to produce a third effluent; (e) introducing only a portion of the third effluent into the fourth column to produce a fourth effluent; (f) allowing the fourth effluent to pass through a mass spectrometer.

Abstract: A gas chromatographic method for detecting a marker compound in a fuel by (a) introducing a sample of fuel into a first capillary column coated with a stationary phase based on polydimethylsiloxane and allowing the sample to flow through the first column to produce a first effluent; (b) allowing the first effluent to pass through a detector and identifying a retention time range in it which includes a retention time of the marker compound; (c) introducing only a portion of the first effluent stream which is within the retention time range into a second capillary column coated with either (i) an ionic sorbent or (ii) a polyethylene glycol, and allowing said portion to flow through the second capillary column to produce a second effluent stream; and (d) allowing the second effluent to pass through a detector; wherein the marker compound has formula Ar(R2)m(OR1)n and is present in the fuel at a level from 0.01 ppm to 100 ppm.