부산대학교 도서관

In the present work, a counter current salting-out homogenous liquid–liquid extraction combined with deep eutectic solvent-based–solidification of floating organic droplet-dispersive liquid–liquid microextraction has been used for the extraction of some antibiotics from hamburger and cow liver samples before their quantitative analysis by ion mobility spectrometry. In this process after removing the lipid from the sample, a mixture of sodium hydroxide solution and acetonitrile is added to the sample and the obtained mixture is vortexed. After that, the supernatant is passed through the glass tube filled with sodium sulphate. By this action the homogenous state is broken and the tiny droplets of acetonitrile are separated and collected on top of the tube. The separated acetonitrile is mixed with newly synthesised choline chloride: pivalic acid deep eutectic solvent at μL–level and immediately dispersed into deionised water. After placing the mixture into an ice bath, the solidified drop (extraction solvent containing the analytes) is removed and injected into ion mobility spectrometry for quantitative analysis. Under the optimised extraction conditions, the method revealed good extraction recoveries (67–90%), high enrichment factors (670–900), satisfactory repeatability (relative standard deviation ≤ 6.2) and low limits of detection (1.7–2.8 ng g−1). Finally, the introduced approach was applied to the analysis of the investigated antibiotics (penicillin G, oxytetracycline and tilmicosin) in the various hamburger and cow liver samples marketed in Tabriz, Iran. [ABSTRACT FROM AUTHOR]