Design of sulfonic acid-functionalized hyper cross-linked polymer as a mixed-mode sorbent for nitroimidazoles detection.

Accurate monitoring of nitroimidazole antibiotics (NDZs) in environmental and food matrices is critical for safeguarding public health and food safety. In this study, a novel sulfonic acid-functionalized hyper-cross-linked polymer (NDF-TPE-HCP) was synthesized via Friedel-Crafts alkylation reaction. The polymer exhibited unique mixed-mode interactions, which enabled efficient extraction of NDZs. Leveraging its strong ExEf, NDF-TPE-HCP was integrated into a solid-phase extraction system coupled with HPLC for the analysis of NDZs (metronidazole, ronidazole, secnidazole, dimetridazole and ornidazole) in water and fish muscle. The developed method demonstrated a good linearity with NDZs concentrations from 0.07 to 400 ng/g (or ng/mL) with the correlation coefficients (R2) ≥ 0.9972. Moreover, low limits of detection for the analytes (0.02-5.00 ng/g (or ng/mL)) were achieved. The method recoveries ranged from 85.2 % to 118.0 %, with the relative standard deviation (RSD) ≤ 9.8 %. The NDF-TPE-HCP based method can serve as a robust and sensitive tool for monitoring NDZs residues.