Ultrasound-assisted dispersive liquid-liquid microextraction for determination of enrofloxacin in surface waters

This work describes the development of an HPLC-FLD methodology for separation five fluoroquinolones (ciprofloxacin, enrofloxacin, sarafloxacin, norfloxacin and levofloxacin) followed by optimization DLLME process clean-up preconcentration enrofloxacin in samples seawater river water. The mobile phase used chromatographic consisted methanol: phosphate buffer (NaHPO4 H2O 0.04 M pH 3 with H3PO4 85%), gradient eluted at a ratio 20:80 (v:v). flow was maintained 1.2 mL min−1. For ultrasonic-assisted dispersive liquid-liquid microextraction (UA-DLLME), following conditions were used: 8 sample adjusted to 8, extraction solvent: 500 μL chloroform, acetonitrile; vortexed sonicated 2 min, each. enrichment factor (EF) 54.7 recovery 70%, achieving limit detection (LOD) 0.11 µg L−1. Repeatability intermediate reproducibility presented values relative standard deviation (RSD) lower than 2%. Finally, optimized method applied analysis water detected both concentration 0.20 L−1 0.12 seawater. However, tests performed evaluate matrices' effects on performance, recoveries 72 ± 6.1 27 8.3 These results demonstrate that hereby developed is only suitable low salinity content.