Dipyrromethenes and azadipyrromethenes as markers for petroleum products

A method of detecting an adulterated petroleum product comprising spectroscopically analyzing a portion of the petroleum product for a presence of a marker, wherein the marker consists of a single dye, and wherein the single dye is a a halogenated-boron dipyrromethene dyes characterized by the following structure:

• where each R is independently selected from the group consisting of hydrogen, an alkyl group, a branched alkyl group, an alkoxy group, a branched alkoxy group, an amino group, an alkylamino group, a dialkylamino group, a thiol group, an alkylthio group, an alkylester group, an alkyl amide group, a halide group, and a nitro group, wherein the presence of a marker is indicative of adulteration of the petroleum product, wherein the petroleum product is a petroleum fuel, wherein the dye is characterized by a resistance to solvatochromatic-based shifting of a fluorescence response when mixed with the petroleum fuel comprising a fuel additive and wherein the dye is present in an amount of from about 0.1 ppb to about 10,000 ppb.

A method comprising adding a covert dye to a petroleum fuel comprising an oxygenate, wherein the covert dye consists of a single dye, and wherein the single dye is a halogenated-boron dipyrromethene dye characterized by the following structure:

• where each R is independently selected from a hydrogen, an alkyl group, a branched alkyl group, an alkoxy group, a branched alkoxy group, an amino group, an alkylamino group, a dialkylamino group, a thiol group, an alkylthio group, an alkylester group, an alkyl amide group, a halide group and a nitro group wherein the convert dye is characterized by a resistance to solvatochromatic-based shifting of its fluorescent response when mixed with the petroleum fuel comprising the oxygenate and wherein the dye is present in an amount of from about 0.1 ppb to about 10,000 ppb.