Original research articleDetermination of fluoroquinolones in fishes using microwave-assisted extraction combined with ultra-high performance liquid chromatography and fluorescence detection

- Performance of an extraction method to determine five fluororoquinolones in fishes.
- Combination of MAE and SPE for extracting fluoroquinolones in fishes.
- Proposed method combines selectivity, resolution, low cost and good results.

A new analytical methodology based on ultra-high performance liquid chromatography with fluorescence detection (UHPLC-FD) has been developed for the determination of five fluoroquinolone antibiotics (FQs) used in aquaculture (norfloxacin, ciprofloxacin, enrofloxacin, danofloxacin and sarafloxacin) in fish muscles (e.g. gilthead seabream (Sparus aurata)). The extraction and determination process was carried out by combining microwave-assisted extraction (MAE) along with a clean-up and pre‐concentration step with solid phase extraction (SPE) followed by UHPLC-FD detection. The effects of different variables on MAE-SPE were studied and optimized using an experimental design. Validation was made in accordance with Decision 2002/657/EC. CCα and CCβ were determined according to the maximum residue limit (MRL). The method detection limit (MDL) of the entire process ranged between 0.1 and 6.0 ng g−1. The recoveries obtained at two spiked concentrations levels (25 and 250 ng g−1) were greater than 90%, and the relative standard deviation was less than 8.7%. The developed methodology was successfully applied for the evaluation of the presence of FQs in fish muscle samples from aquaculture farms bought in various commercial shops in Gran Canaria Island (Spain).