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Synthesis and Application of Nanocomposites Containing Metallic Nanoparticles for Microextraction of Environmental and Biological Samples

Banihashemi, Solmaz | 2016

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 48702 (03)
  4. University: Sharif University of Technology
  5. Department: Chemistry
  6. Advisor(s): Bagheri, Habib
  7. Abstract:
  8. This thesis deals with the synthesis and characterization of some nanostructured conductive polymers and their applications toward microextraction of drugs, environmental pollutants and pesticides from aqueous and biological samples. In chapters 3–6, silver nanoparticles and their relevant nanocomposites were applied as the desired extracting media while in the last chapter, a polyaniline nanocomposite, containing titanium oxide nanoparticles, was synthesized and employed as an efficient medium for the extraction purposes. In the first work, a nanocomposite based on polyaniline-silver nanoparticles (PANI-Ag NPs) was synthesized and used as an extraction medium for microextraction in packed syringe (MEPS) of drug furosemide from urine samples. The limit of detection (S/N=3) and limit of quantification (S/N=10) were 7 and 15 µg L-1, respectively. The developed method was applied to the determination of furosemide in real urine samples obtained from a healthy female volunteer. The desired drug was easily detected in different interval times. Next, the pre-synthesized Ag NPs were applied to prepare a nanocomposite of silica-polydiphenylamine doped with Ag NPs (Ag-SiO2-PDPA) using the sol-gel technology. PDPA was mixed with butanethiol capped Ag NPs and added to the silica sol solution. The Ag NPs were stabilized as a result of their adsorption on the SiO2 spheres. This nanocomposite was employed as an efficient sorbent for micro-solid-phase extraction of some selected pesticides from aquatic samples. Limits of detections were in the range of 0.02-0.05 µg L-1 and the relative standard deviation (RSD %) with four replicates was in the range of 6-10%. Then, a nanocomposite from polydopamine, silver nanoparticles, and polypyrrole (PDA-Ag-PPy) was synthesized and used for the microextraction in packed syringe (MEPS) of tricyclic antidepressants from urine samples. The PDA-Ag-PPy composite was prepared in-situ by the reduction of silver ion doped PPy during oxidative polymerization of dopamine. The limits of detection were in the range from 0.03 - 0.05 µg L-1 and the relative recoveries were between 88 and 104% for the analysis of spiked urine samples.In the fourth work, colloidal Ag NPs with narrow size distribution and high stability was synthesized in water–in–oil microemulsion. In this procedure, microemulsions were prepared by dissolving the bis (2-ethylhexyl) sulfosuccinate sodium salt (surfactant) in n–decane as the oil phase. Hydrazine hydrate was used to reduce the Ag ions. The polymeric composites were prepared by dispersing the PT powder with the pre-formed Ag NPs solution in n–decane. The 2–dimentional synthesized nanocomposite of PT–Ag was introduced as a needle trap device (NTD) sorbent for the extraction and determination of some selected polycyclic aromatic hydrocarbons, as model analytes. The effect of Ag NPs amount on nanocomposite efficiency was evaluated. The limits of detections and limit of quantification were in the range of 0.002–0.01 ng mL−1 and 0.01-10 ng mL-1, respectively. Finally, a titanium dioxide–polyaniline (TiO2–PANI) core–shell nanocomposite was synthesized and implemented as an efficient sorbent for needle trap extraction (NTE) of some volatile organic compounds from urine samples. The TiO2 NPs were encapsulated inside the conducting polymer shell, by adapting the in–situ dispersing approach. The limits of detection and limits of quantification values were in the range of 0.5–3 ng L−1 and 2–5 ng L−1, respectively. The applicability of the developed NT method was examined by analyzing urine samples and the relative recovery percentages for the spiked samples were in the range of 81–105%
  9. Keywords:
  10. Titanium Dioxide Nanoparticles ; Conductive polymer nanocomposite ; Needle Trap Extraction ; High Performance Liquid Chromatography ; Silver Nanoparticles ; Micro-Solid Phase Extraction ; Conductive Polymer

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