Rapid and selective detection of tetracyclic antibiotics in environmental water using Cu2+-doped hydrophilic imprinted melamine resin

Antibiotic contamination in environmental waters often occurs at low residue levels, necessitating pre-analysis concentration. To address this, we synthesized a hydrophilic molecularly imprinted resin (MIR) using melamine, urea, and formaldehyde as monomers, with oxytetracycline as the template molecule. Enhanced adsorption efficiency was achieved by doping the resin with Cu2+, which forms stable complexes with oxytetracycline. This Cu2+-doped MIR (Cu-MIR) was employed as a selective adsorbent in solid-phase extraction (SPE) to enrich four tetracycline antibiotics (TCs) from aqueous solutions. The optimized parameters for Cu-MIR in environmental water sample analysis resulted in linear detection ranges from 0.20 to 40 ng/mL, recoveries between 80.2 % to 102.4 %, relative standard deviations ≤ 9.0 %, a detection limit of 0.1 ng/mL, and the enrichment factors were between 4.79–5.13, as determined by HPLC-MS. Given its diverse adsorption mechanisms and specificity, Cu-MIR shows promise for practical applications in real-world sample analysis.