Based on a polyglycidyl methacrylate-co-ethylene glycol dimethacrylate copolymer (PGMA-co-EGDMA), nitrogen, sulfur, and aromatic compounds were removed from light and heavy gas oil feeds. The method in which PGMA-co-EGDMA is synthesized can influence the textural and chemical characteristics of the polymer and thus its adsorption capacity. Studies have shown that using cerium initiated graft polymerization in PGMA-co-EDGMA synthesis can improve the adsorption capacity of the polymer. In this work, nitrogen, sulfur, and aromatics removal capacity of (PGMA-co-EGDMA) polymer incorporated with tetranitrofluorenone (TENF) via 1,3 diaminopropane (PDA) using cerium initiated graft polymerization were compared with the same polymer without using cerium. A third polymer with different linker, ethylenediamine (EDA) instead of PDA, was synthesized using cerium initiated graft polymerization to inspect the impact of the linker on the removal efficiency. The synthesized polymers were characterized using different characterization methods. The synthesized polymers were tested at different nitrogen, sulfur, and aromatic content using light and heavy gas oil feeds. In addition, the removal capacity of the synthesized polymers toward nonbasic nitrogen were determined using automatic potentiometric titrator. Results have shown that using cerium graft polymerization on the synthesis of PGMA-co-EGDMA polymer reduced surface area, pore size and volume, and amount TENF grafted, thus decreasing the removal efficiency of nitrogen, sulfur, and aromatics. However, polymer selectivity toward nonbasic nitrogen was not affected by cerium graft polymerization. Furthermore, the adsorption capacity of the PGMA-co-EGDMA decreased with increasing linker length due to steric hindrance effect that influences the adsorption capacity of the polymer.