Synthesis of hydrogel adsorbent for high selectivity and strong chelate removal of transition metals Cr, Cu and Ni was accomplished via sol-gel method using ligand monomers maleic acid and (2, 2' ethylenedioxy) bis (ethylamine) reagent. We obtained a 14-membered macrocyclic functional unit called poly (1, 4-dioxa-7, 12-diazacyclotetradecane-8, 11-dione) as the main active sites for metal adsorption. The new adsorbent's cross-linked polymer chains was clearly visualized using SEM spectroscopy; whereas the FTIR, C-13 NMR and EDX techniques demonstrated its structural and functional groups. With an improved chelating power, this macrocyclic hydrogel was able to ignore non-target substrates, instead showing high specificity for only Cu, Cr and Ni from both single and multi-ion competitive aqueous solutions, in the order Cr > Cu > Ni. Pseudo-second order kinetic model aptly described the adsorption process, revealing chemisorption as the main mechanism which proceeded based on the host-guest chelation principle of metal ions onto the gel's macrocyclic active sites. Thus a high performance, high selectivity adsorbent system was achieved using active sites bearing substrate recognition and isolation properties.