Supramolecular solvent based liquid-liquid microextraction for preconcentration of selected fluoroquinolone antibiotics in environmental water sample prior to high performance liquid chromatographic determination

Background and Objectives: A rapid, simple and environmental friendly supramolecular solvent (SUPRAS) based liquid-liquid microextraction method for preconcentration of ciprofloxacin (CIPRO), danofloxacin (DANO) and enrofloxacin (ENRO) from wastewater was developed. Methods: This microextraction technique was coupled with high-performance liquid chromatography equipped with a diode array detector (HPLC-PDA) for detection and separation of the antibiotics. The SUPRAS composed of decanoic acid and tricaprylymethylammonium chloride. Optimum conditions for the extraction and preconcentration of all the antibiotics were obtained using surface response methodology (RSM) based on Box-Behnken design. Results: Under optimum conditions, the limits of detection (LOD) and limit of quantification (LOQ) ranged from 0.06-0.14 µg L⁻¹ and 0.22-0.47 µg L⁻¹, respectively with the preconcentration factors ranging from 153-241. The linear dynamic ranges were between LOQ and 850 µg L⁻¹ with correlation coefficients ranging from 0.9928 to 0.9999. The intra-day (n = 15) and inter-day (n = 5) precisions (ex-pressed in terms of %RSD) for 50 µg L⁻¹ of CIPRO, DANO and ENRO were in the range of 3.3–4% and 4.1–5.8%, respectively. Conclusion: Lastly, the developed method was used for the extraction, preconcentration and quantification of selected CIPRO, DANO and ENRO in influent and effluent wastewater samples.