Abstract: A method of preparing a reference material for fluorescence spectroscopy by impregnating or otherwise placing one or more fluorophores into a solid polymethyl methacrylate (PMMA) matrix. The method can include impregnating or otherwise placing the one or more fluorophores into the solid PMMA matrix by melt mixing a powder of each of the one or more fluorophores with the solid PMMA matrix to provide a mixed product comprising a homogeneous distribution of the one or more fluorophores in the PMMA and injection molding the mixed product to provide the reference material having a final shape; and/or polymerizing MMA in the presence of one or more fluorophores to form the solid PMMA matrix.

Abstract: A composition comprising a fuel and at least one compound characterized by Formula I: wherein X is carbon, oxygen, or sulfur; R1 and R2 each independently are hydrogen, a C1 to C20 alkyl, or a C6 to C10 aryl; R3 and R3? each independently are hydrogen or a C1 to C4 alkyl; R4 and R4? each independently are hydrogen, a C1 to C4 alkyl, a C4 to C10 cycloalkyl, or a C6 to C10 aryl; R5 and R5? each independently are a C4 to C10 alkyl; R6 and R6? each independently are hydrogen or a C1 to C6 alkyl; and R7 and R7? each independently are hydrogen or a C1 to C4 alkyl; and wherein the compound of Formula I when subjected to GC-MS using electron ionization at greater than about 70 eV produces at least one ion having a mass-to-charge ratio of from 300 to 600.

Abstract: A composition comprising a fuel and at least one compound characterized by Formula I: wherein X is carbon, oxygen, or sulfur; R1 and R2 each independently are hydrogen, a C1 to C20 alkyl, or a C6 to C10 aryl; R3 and R3? each independently are hydrogen or a C1 to C4 alkyl; R4 and R4? each independently are hydrogen, a C1 to C4 alkyl, a C4 to C10 cycloalkyl, or a C6 to C10 aryl; R5 and R5? each independently are a C4 to C10 alkyl; R6 and R6? each independently are hydrogen or a C1 to C6 alkyl; and R7 and R7? each independently are hydrogen or a C1 to C4 alkyl; and wherein the compound of Formula I when subjected to GC-MS using electron ionization at greater than about 70 eV produces at least one ion having a mass-to-charge ratio of from 300 to 600.

Abstract: A method of forming a composition comprising contacting a fuel and at least one compound of Formula I: wherein X is carbon, oxygen, or sulfur; R1 and R2 each independently are hydrogen, a C1 to C20 alkyl, or a C6 to C10 aryl; R3 and R3? each independently are hydrogen or a C1 to C4 alkyl; R4 and R4? each independently are hydrogen, a C1 to C4 alkyl, a C4 to C10 cycloalkyl, or a C6 to C10 aryl; R5 and R5? each independently are a C4 to C10 alkyl; R6 and R6? each independently are hydrogen or a C1 to C6 alkyl; and R7 and R7? each independently are hydrogen or C1 to C4 alkyl; and wherein the compound of Formula I when subjected to GC-MS using electron ionization at greater than 70 eV produces at least one ion having a mass-to-charge ratio of 300 to 600.

Abstract: A composition comprising a fuel and at least one compound characterized by Formula I: wherein X is carbon, oxygen, or sulfur; R1 and R2 each independently are hydrogen, a C1 to C20 alkyl, or a C6 to C10 aryl; R3 and R3? each independently are hydrogen or a C1 to C4 alkyl; R4 and R4? each independently are hydrogen, a C1 to C4 alkyl, a C4 to C10 cycloalkyl, or a C6 to C10 aryl; R5 and R5? each independently are a C4 to C10 alkyl; R6 and R6? each independently are hydrogen or a C1 to C6 alkyl; and R7 and R7? each independently are hydrogen or a C1 to C4 alkyl; and wherein the compound of Formula I when subjected to GC-MS using electron ionization at greater than about 70 eV produces at least one ion having a mass-to-charge ratio of from 300 to 600.

Abstract: A method of forming a composition comprising contacting a fuel and at least one compound of Formula I: wherein X is carbon, oxygen, or sulfur; R1 and R2 each independently are hydrogen, a C1 to C20 alkyl, or a C6 to C10 aryl; R3 and R3? each independently are hydrogen or a C1 to C4 alkyl; R4 and R4? each independently are hydrogen, a C1 to C4 alkyl, a C4 to C10 cycloalkyl, or a C6 to C10 aryl; R5 and R5? each independently are a C4 to C10 alkyl; R6 and R6? each independently are hydrogen or a C1 to C6 alkyl; and R7 and R7? each independently are hydrogen or C1 to C4 alkyl; and wherein the compound of Formula I when subjected to GC-MS using electron ionization at greater than 70 eV produces at least one ion having a mass-to-charge ratio of 300 to 600.

Abstract: A compound characterized by Formula I: wherein X can be carbon (C), oxygen (O), or sulfur (S); R1 and R2 can each independently be hydrogen, a C1 to C20 alkyl group, or a C6 to C10 aryl group; R3 and R3? can each independently be hydrogen or a C1 to C4 alkyl group; R4 and R4? can each independently be hydrogen, a C1 to C4 alkyl group, a C4 to C10 cycloalkyl group, or a C6 to C10 aryl group; R5 and R5? can each independently be a C4 to C10 alkyl group; R6 and R6? can each independently be hydrogen or a C1 to C6 alkyl group; and R7 and R7? can each independently be hydrogen or a C1 to C4 alkyl group; and wherein the compound characterized by Formula I when subjected to gas chromatography-mass spectrometry (GC-MS) using electron ionization produces at least one ion having a mass-to-charge ratio of greater than about 300 at an ionization energy of equal to or greater than about 70 eV.

Abstract: A method of determining adulteration of a fuel including subjecting to an analytical technique a marked fuel mixture comprising (a) a fuel; (b) a compound characterized by Formula I: wherein X is carbon, oxygen, or sulfur; when X is O or S, R1 and R2 are lone non-bonding electron pairs; when X is C, R1 and R2 each independently are hydrogen, C1 to C20 alkyl, or C6 to C10 aryl; R3 and R3? each independently are hydrogen or C1 to C4 alkyl; R4 and R4? each independently are hydrogen, C1 to C4 alkyl, C4 to C10 cycloalkyl, or C6 to C10 aryl; R5 and R5? each independently are C4 to C10 alkyl; R6 and R6? each independently are hydrogen or C1 to C6 alkyl; and R7 and R7? each independently are hydrogen or C1 to C4 alkyl; and (c) a heavy compound, wherein the heavy compound comprises a compound of Formula I having at least one atom replaced with an isotope tag.

Abstract: The present invention relates to a method of preparing lanthanide-doped NaYF4 nanocrystals, the method comprising: (A) providing a first solution comprising a non-coordinating solvent, a fatty acid coordinating ligand, sodium trifluoroacetate, yttrium trifluoroacetate, a first doping lanthanide trifluoroacetate and a second doping lanthanide trifluoroacetate, and a second solution comprising the non-coordinating solvent and the fatty acid coordinating ligand, the first and second solutions being substantially free of water and oxygen; (B) in an inert atmosphere, slowly adding the first solution heated at a temperature between about 100° C. and about 150° C. to the second solution heated at temperature between about 290° C. and about 330° C., thereby producing a reaction mixture containing the nanocrystals; and (C) recovering the nanocrystals from the reaction mixture.

Abstract: The present invention relates to a method of preparing lanthanide-doped NaYF4 nanocrystals, the method comprising: (A) providing a first solution comprising a non-coordinating solvent, a fatty acid coordinating ligand, sodium trifluoroacetate, yttrium trifluoroacetate, a first doping lanthanide trifluoroacetate and a second doping lanthanide trifluoroacetate, and a second solution comprising the non-coordinating solvent and the fatty acid coordinating ligand, the first and second solutions being substantially free of water and oxygen; (B) in an inert atmosphere, slowly adding the first solution heated at a temperature between about 100° C. and about 150° C. to the second solution heated at temperature between about 290° C. and about 330° C., thereby producing a reaction mixture containing the nanocrystals; and (C) recovering the nanocrystals from the reaction mixture.