| abstract |
"METHOD FOR MARKING A LIQUID OIL HYDROCARBON". Method for marking liquid petroleum hydrocarbons. The method comprises adding to the petroleum liquid hydrocarbon at least one substituted anthraquinone dye having formula (I) wherein X is O or S; Y is 0, NR7 or S; R 13 and R 12 independently are hydrogen, alkyl, aryl, aralkyl, heteroaryl, heterocyclyl or alkanoyl; R 3 and R 5 independently are alkyl, aryl, aralkyl, heteroaryl or heterocyclic; R 4 and R 6 independently are hydrogen or alkyl; R7 is hydrogen or alkyl; and where the substituted anthraquinone dye (s) have a maximum absorption in the range of 600 nm to 750 nm. |