Tracers and method of marking liquids

Abstract

A method of marking a hydrocarbon liquid comprising adding to said hydrocarbon liquid a tracer compound, the tracer compound being a substituted biphenol ether having a core structure of Formula I, wherein the two R groups are the same or different and selected from straight chain, branched or cyclic alkyl groups, phenyl or substituted phenyl groups, benzyl or substituted benzyl groups, or the two R groups form a single substituent linked intramolecularly to both oxygen atoms, and wherein one or both of the aromatic rings of the core structure is further substituted with at least one non-planar group.

1 - 16 . (canceled) 
     
     
         17 . A method of marking a hydrocarbon liquid comprising adding to said hydrocarbon liquid a tracer compound, the tracer compound being a substituted biphenol ether having a core structure of Formula I: 
       
         
           
           
               
               
           
         
         wherein the two R groups are the same or different and selected from straight chain, branched or cyclic alkyl groups, phenyl or substituted phenyl groups, benzyl or substituted benzyl groups, or the two R groups form a single substituent linked intramolecularly to both oxygen atoms, and 
         wherein one or both of the aromatic rings of the core structure is further substituted with at least one non-planar group. 
       
     
     
         18 . The method according to  claim 17 ,
 wherein the or each non-planar group consists of atoms selected from the group carbon, hydrogen, and oxygen.   
     
     
         19 . The method according to  claim 17 ,
 wherein the or each non-planar group is a C 4  to C 20  non-planar group.   
     
     
         20 . The method according to  claim 17 ,
 wherein the or each non-planar group is a non-planar alkyl group.   
     
     
         21 . The method according to  claim 20 ,
 wherein the non-planar alkyl group is a branched alkyl group.   
     
     
         22 . The method according to  claim 21 ,
 wherein the branched alkyl group is a tert-butyl group.   
     
     
         23 . The method according to  claim 17 ,
 wherein one or both of the aromatic rings of the core structure is substituted with at least two of the non-planar groups.   
     
     
         24 . The method according to  claim 17 ,
 wherein the substituted biphenol ether is an ortho-biphenol ether or a para-biphenol ether.   
     
     
         25 . The method according to  claim 24 ,
 wherein the substituted biphenol ether is an ortho-biphenol ether.   
     
     
         26 . The method according to  claim 17 ,
 wherein the R groups consist of atoms selected from the group carbon, hydrogen, and oxygen.   
     
     
         27 . A method according to  claim 17 ,
 wherein the R groups are C 1  to C 20  groups.   
     
     
         28 . The method according to  claim 17 , wherein the tracer compound is added to the hydrocarbon liquid to yield a concentration of tracer compound in a range 1 μg/l to 10,000 μg/l. 
     
     
         29 . A method of identifying a source of a hydrocarbon liquid comprising:
 analysing said hydrocarbon liquid to detect a tracer compound as defined in  claim 17 ; and   determining the source of the hydrocarbon liquid by the presence of the tracer compound.   
     
     
         30 . A hydrocarbon liquid comprising a tracer compound as defined in  claim 17 . 
     
     
         31 . The hydrocarbon liquid according to  claim 30 , wherein the hydrocarbon liquid is a diesel fuel, a gasoline fuel, a liquified petroleum gas fuel, or a biofuel in which the tracer compound is disposed. 
     
     
         32 . The hydrocarbon liquid according to  claim 30 , wherein the tracer compound is present at a concentration in a range 1 μg/l to 10,000 μg/l.