ABSTRACT
A cheap and simple sample preparation method, consisting of a dispersive solid-phase method and an ad-sorbent, activated carbon decorated PAN nanofibers, was employed and used for the extraction of antibiotics (ciprofloxacin, danofloxacin, and enrofloxacin) in wastewater. Electrospun PAN nanofibers that were deco-rated with activated carbon produced from waste tires were used as the solid phase and the antibiotics analyzed by using high-performance liquid chromatography. Parameters such as pH, mass of adsorbent (MA), extraction volume (EV), and extraction time (ET) were optimized owing to their potential effect on the extraction of antibiotics from water. The recovery of all antibiotics was satisfactory, in the range of 90％–99％. The limits of detection and quantification were 0.05, 0.11, 0.20, and 0.53, 1.21, 2.17 μg/L, respectively. The precision was determined from the repeatability and reproducibility and expressed as the intra-day (n = 20) and inter-day (n = 5) precision. The intra-day and inter-day precision was reported in terms of the per-centage relative standard deviation, which was 3％ and 4％, respectively. The adsorption capacity of the ac-tivated carbon-decorated PAN nanofibers was satisfactory, and the reusability of the adsorbent was im-pressive when reused ten times. The accuracy of the dispersive solid phase extraction (DSPE) was validated by spike recovery tests; the results proved the reliability and efficiency of adsorbing antibiotics from was-tewater. Finally, the proposed method was applied to wastewater samples collected from a wastewater treatment plant, which included influent, secondary, and effluent wastewater.
ABSTRACT
A new method was proposed for analysis of the organic compounds in cigarette smoke by high resolution Orbitrap mass spectrometry based on polyacrylonitrile-silica (PAN-SiO2) nanofiber membrane extraction and methanol elution.Hydrophobic PAN-SiO2 nanofiber membrane which was used to enrich small molecular organic compounds in cigarette smoke was prepared by the technology of electrospinning.Several parameters including the concentrations of PAN and SiO2 nanopartical,elecrospining voltage,needle aperture and flow rate of spinning solution were optimized.Under the optimal conditions,a PAN-SiO2 nanofiber membrane with good adsorption performance and great physical strength was obtained.A total of 21 compounds including acetone,styrene,acrolein,isoprene,and acrylonitrile were identified by analyzing the cigarette smoke with Orbitrap MS spectrometry in the positive ion mode.Six organic acids including salicylic acid,malic acid and lactic acid were detected in negative ion mode.The limits of detection and quantification for nicotine were 0.071 ng/L and 0.236 ng/L,respectively.
ABSTRACT
Preparations of polyacrylonitrile (PAN) are now being considered as possible new therapeutic embolization agents. This study evaluated two different liquid PAN formulations and a solid particle form (particle diameters, 100-400?m). Eighteen rabbits underwent unilateral renal embolization with one of the three different preparations (n=6 in each group). PAN was effective in causing infarcts in all embolized kidneys, which were documented with both angiograms and pathologic findings. These preliminary results show that PAN may have promise as an effective agent for clinical renal embolizations.