Evaluation of a Selective Approach for the Determination of 5-Nitroimidazoles in Aquaculture Products by Capillary Liquid Chromatography Using Molecularly Imprinted Solid-Phase Extraction

Capillary liquid chromatography with UV detection is proposed for the determination of 5-nitroimidazole residues in aquaculture products. The separation was carried out in a C18 column at 20 °C, using a mobile phase consisting of water and acetonitrile, at 7 μL/min and 320 nm as detection wavelength. Furthermore, full loop injection mode (8 μL) was selected and water was considered as injection solvent. The optimized method was applied to the monitoring of nine 5-nitroimidazoles, including three metabolites, in crab, salmon, prawn, and velvet swimming crab. Molecularly imprinted solid-phase extraction has been evaluated for sample cleanup. The method was characterized in all the matrices in terms of linearity (R ² ≥ 0.9964), precision (repeatability, RSD ≤ 7.9%, and reproducibility, RSD ≤ 11.1%) and trueness (recoveries between 80.4 and 108.7%). Decision limits, CCα, ranging from 0.2 to 1.5 μg/kg and detection capabilities, CCβ, from 0.2 to 1.8 μg/kg, were obtained.