Preconcentration and separation of trace acetylspiramycin in environmental samples by use of ionic liquid-(NH4)2SO4 aqueous two-phase flotation system

Ionic liquid aqueous two-phase flotation (ILATPF) consisting of ionic liquid aqueous two-phase system (ILATPS) and solvent sublation (SS), which is a novel, non-toxic and green sample pretreatment technique coupled with molecular fluorescence spectrophotometry, was developed for the simultaneous separation, enrichment and rapid analysis of acetylspiramycin. In this ILATPF system of 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF₄)/(NH₄)₂SO₄, the effects of the solution pH, condition for phase separation, sublation time and gas flow rate were investigated and discussed in details, and the optimal conditions for ILATPF were obtained. Under the optimum conditions, this method was successfully applied to analysis of acetylspiramycin in environmental samples with the recovery of 85.8-90.4%, the detection limit of 0.04 μg/mL, and the relative standard deviation of 4 μg/mL for 10 parallel determination was lower than 0.33%. This method showed to be promising for separation and enrichment of trace acetylspiramycin as well as other substances in the environment.