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Magnetic Field Assistedand Flow Injection μ-Solid Pahse Extraction Techniques

Khanipour Mehrin, Peyman | 2014

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 46149 (03)
  4. University: Sharif University of Technology
  5. Department: Chemistry
  6. Advisor(s): Bagheri, Habib
  7. Abstract:
  8. The main goal of this thesis was to develop μ-solid extraction techniques using electrspun nanofibers under the influence of magnetic field along with flow injection system. The thesis is divided into two sections:The first chapter deals with the use of magnetic field for improving μ-solid phase extraction efficiencies. After preparing the magnetic-based electrospun nanofibers (PBt/MNPs), sufficient numbers of disc from the prepared electrospun composite mat were cut and used as packing materials in a cartridge. The prepared system was coupled on-line to liquid chromatography for microextraction of selected drugs of furosemide, naproxene, diclofenac and clobetasol propionate. The homogeneity and the porosity of the electrospun nanofibers were studied using the scanning electron microscopy (SEM) and FT-IR spectra was used to characterize the electrospun magnetic composite. Major parameters affecting the extraction efficiency were optimized. The limits of detection (LOD)of four drugs furosemide, naproxene, diclofenac and clobetasol propionate were1.6, 0.4, 0.8 and 1.3 μg L−1respectively under optimized conditions. Also the limits of quantification (LOQ)were 4, 1, 2 and 3 μg L−1for mentioned drugs respectively. Relative standard addition percentage (RSD%) for three replicates at three concentration of 6, 100 and 500 μg L−1 of drugs were 5.9-8%. Acceptable linear range of the calibration curve with two order of magnitude was obtained (R2 = 0.99). The method was applied to the determination of these selected drugs in urfLine samples. The results indicated that this method has sufficient potential for enrichment and determination of drugs in body fluids.The second part of thesis introduces flow injection μ-solid phase extraction (FI-μ-SPE) technique based on a novel electrospun polyaniline (PANI) nanofibers combined with gas chromatography-mass spectrometry. The method was used for determination of trace residues of triazines herbiscides. The main objective was towards automation of solvent desorption. The PANI nanofibers were prepared by removing the polyvinyl alcohol (PVA) as template from electrospun blend of electrospun PVA/PANI nanofibers in boiling water. A HPLC pump was used for flowing the sample and desorption solvent. Again, sufficient numbers of disc were cut from the prepared electrospun composite mat and used as packing materials in a cartridge. The SEM and IR instruments were used for examination of porosity and characterization of the naofibers, respectively. Major parameters affecting the extraction efficiency were optimized. At the optimum conditions, RSD% values for a double distilled water spiked with the selected triazines were in range of %8.9-9.5 (n = 3) while the limit of detection (LOD) for atrazine, ametryn and terbutryn were 0.09, 0.05 and 0.03 μg L−1 respectively. Also the limits of quantification (LOQ) were 0.5, 0.1 and 0.1 μg L−1for mentioned triazines respectively. Acceptable linear range of the calibration curve with three order of magnitude was obtained. For validation of the developed method and sorbent capability, the analysis of paddy, well and tap water samples were implemented and successful results confirmed its strong potential for pre-concenration and determination of triazines in environmental samples
  9. Keywords:
  10. Constant Magnetic Field ; Electrospun Nanofibers ; Micro-Solid Phase Extraction ; Drugs ; Triazines Herbicides ; High Performance Liquid Chromatography ; Gas Chromatography/Mass Spectrometry (GC/MS) ; Flow Injection Analysis (FIA)

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