Ultrasound-assisted dispersive liquid-liquid microextraction for determination of fluoroquinolones in pharmaceutical wastewater.

A simple and rapid ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) coupled with liquid chromatography-ultraviolet detection (LC-UV) was developed for the determination of four fluoroquinolones (ofloxacin, norfloxacin, enrofloxacin, and lomefloxacin) in pharmaceutical wastewater samples. Various parameters affecting the extraction efficiency including type and volume of extraction and dispersive solvents, sample pH, and extraction time were investigated. Good linear relationships were obtained for all analytes in a range of 0.01-2.0 μg/ml with LODs ranged from 0.14 to 0.81 μg/l. Average recoveries at three spiking levels were over the range of 82.7-110.9% with RSD less than 5.2% (n=3). Under the optimized conditions the enrichment factors for the four fluoroquinolones were ranged from 32 to 134 folds. The presented method was applied for the determination of four fluoroquinolones in pharmaceutical wastewater samples.