Deep eutectic solvent-based nanofluid in vortex-assisted liquid–liquid microextraction of two antibiotics in milk: Application of the method in evaluating the effects of ultraviolet and microwave radiation, as well as sonication on antibiotic deconta

A new eco-friendly and efficient nanofluid based vortex-assisted liquid-liquid microextraction approach was developed for extracting of two antibiotics in milk samples. Eight new nanofluids were prepared utilizing graphene oxide aerogel as the nanoparticle and deep eutectic solvents. An appropriate amount of zinc sulfate was added to the milk sample. Then, 50 μL of the nanofluid was added to the deproteinized and diluted sample solution. The mixture was vortexed and the cloudy solution obtained was centrifuged. After back extraction, the analytes were analyzed by the determination system. The proposed method showed linear calibration range of 2.73-200 ng/mL with a good correlation coefficient of ≥0.9955. Limits of detection and quantitation were found to be 0.745 and 0.820 ng/mL and 2.48 and 2.73 ng/mL, for oxytetracycline and ciprofloxacin, respectively. The relative standard deviations were ≤ 14.30 %. All results were statistically evaluated and a <i>p</i>-value <0.05 confidence was considered statistically significant. Negligible matrix effect was also confirmed.