The removal and recovery of trace-metal compounds in complex matrices, such as heavy crude petroleum's and shale oils, is a basic problem in the general area of fundamental petroleum chemistry. We are developing innovative methods to remove arsenic compounds from shale oil and vanadium and nickel compounds from heavy crude petroleum's. This involves placing ligands onto polymers that will react with the trace metal compounds present in these matrices. As well, studies directed toward the molecular characterization of the trace-metal compounds in the above-mentioned petroleum's allows selective methods to be utilized in the polymer pendant ligand experiments designed to remove these trace-metals.