Abstract: Method of marking a hydrocarbon liquid includes: adding thereto, a tracer compound of Formula I: wherein, each A is independently selected from the group consisting of (i) a phenyl group, (ii) a phenyl group substituted with one or more halogen atoms, an aliphatic group or a halogenated aliphatic group, (iii) a partially or fully halogenated alkyl group or (iv) a linear branched or cyclic C1-C20 alkyl group, and each B is independently selected from the group consisting of a (i) phenyl, (ii) phenylmethyl group, (iii) a cyclohexyl group, (iv) a cyclohexylmethyl group, (v) a substituted phenyl or phenylmethyl group in which the benzene ring is substituted by at least one substituent selected from the group consisting of a fluorine atom, a partially or fully halogenated alkyl group and a linear, branched or cyclic C1-C20 alkyl group or (vi) a linear, branched or cyclic C1-C20 alkyl group.

Abstract: Method of marking a hydrocarbon liquid includes adding to the liquid a tracer compound of Formula I: wherein, each X is independently hydrogen, bromine, fluorine, a halogenated alkyl group, a linear, branched or cyclic C1-C20 alkyl group, or a phenyl group substituted with one or more halogen atoms, an alkyl group or a halogenated alkyl group; each Y is independently bromine, fluorine, a halogenated alkyl group, a branched or cyclic C1-C9 alkyl group, or a phenyl group substituted with at least one alkyl and/or a halogenated alkyl group; Z is a phenyl group substituted with one or more halogen atoms, an aliphatic or halogenated aliphatic group, a halogenated alkyl group or a linear, branched or cyclic C1-C20 alkyl group, provided that when each Y is a fluorine atom, Z is not a linear or branched C1-C20 alkyl group.

Abstract: A method of measuring the fluorescence of a fluorescent marker compound dissolved or dispersed in a bulk material includes: (a) measuring a characteristic of the fluorescence of a mixture of said bulk material and said fluorescent marker compound; (b) quenching the fluorescence of the fluorescent marker compound to produce a quenched mixture; (c) measuring the characteristic of the fluorescence of the quenched mixture; (d) comparing the fluorescent characteristic of the mixture with the fluorescent characteristic of the quenched mixture; and (e) correcting the measured fluorescent emission characteristic for the effects of the absorbance of the bulk material. The measurement may be further corrected to account for the absorbance of the material which is also known to have an effect on the measured fluorescence. A method of tagging and identifying a bulk material with a fluorescent marker compound, and an apparatus for carrying out the methods are also described.

Abstract: Method of marking a hydrocarbon liquid includes: adding thereto, a tracer compound of Formula I: wherein, each A is independently selected from the group consisting of (i) a phenyl group, (ii) a phenyl group substituted with one or more halogen atoms, an aliphatic group or a halogenated aliphatic group, (iii) a partially or fully halogenated alkyl group or (iv) a linear branched or cyclic C1-C20 alkyl group, and each B is independently selected from the group consisting of a (i) phenyl, (ii) phenylmethyl group, (iii) a cyclohexyl group, (iv) a cyclohexylmethyl group, (v) a substituted phenyl or phenylmethyl group in which the benzene ring is substituted by at least one substituent selected from the group consisting of a fluorine atom, a partially or fully halogenated alkyl group and a linear, branched or cyclic C1-C20 alkyl group or (vi) a linear, branched or cyclic C1-C20 alkyl group.

Abstract: Method of marking a hydrocarbon liquid includes adding to the liquid, a tracer compound of Formula I: wherein, each X is independently selected from a hydrogen, bromine, or fluorine atom, a partially or fully halogenated alkyl group, a linear, branched or cyclic C1-C20 alkyl group and a phenyl group substituted with one or more halogen atoms, an alkyl group or a halogenated alkyl group; each Y is independently selected from a bromine, or fluorine atom, a partially or fully halogenated alkyl group, a branched or cyclic C1-C9 alkyl group and a phenyl group substituted with at least one alkyl and/or a halogenated alkyl group; Z is selected from (i) a phenyl group substituted with one or more halogen atoms, an aliphatic or halogenated aliphatic group, (ii) a partially or fully halogenated alkyl group or (iii) a linear, branched or cyclic C1-C20 alkyl group provided that when each Y is a fluorine atom, Z is not a linear or branched C1-C20 alkyl group.

Abstract: A method of measuring the fluorescence of a fluorescent marker compound dissolved or dispersed in a bulk material includes: (a) measuring a characteristic of the fluorescence of a mixture of said bulk material and said fluorescent marker compound; (b) quenching the fluorescence of the fluorescent marker compound to produce a quenched mixture; (c) measuring the characteristic of the fluorescence of the quenched mixture; (d) comparing the fluorescent characteristic of the mixture with the fluorescent characteristic of the quenched mixture; and (e) correcting the measured fluorescent emission characteristic for the effects of the absorbance of the bulk material. The measurement may be further corrected to account for the absorbance of the material which is also known to have an effect on the measured fluorescence. A method of tagging and identifying a bulk material with a fluorescent marker compound, and an apparatus for carrying out the methods are also described.