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A Superhydrophobic Melamine Formaldehyde Sorbent for Micro Extraction of Pollutants from Aquatic Media

Zeinali, Shakiba | 2016

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 48793 (03)
  4. University: Sharif University of Technology
  5. Department: Chemistry
  6. Advisor(s): Bagheri, Habib
  7. Abstract:
  8. In this project, melamine formaldehyde was chosen as initial substrate for its high porosity. Then for having superhydrophobic surface, surface functional groups were silanized and deactivated as a result. It was assumed that high porosity of prepared sorbent and its nonpolar nature, can increase extraction efficiency. To study extraction efficiency of the prepared sorbent, it was filled inside a needle and used for needle-trap head-space extraction of BTEX (abbreviation for Benzene, Toluene, Ethylbenzene and Xylenes). Needle packed with sorbent was held on headspace of sample containing BTEX and head- space was pumped with a peristaltic pump. Pumping introduces fresh sample to sorbent continuously, and increases extraction efficiency. To increase sensitivity, influential parameters such as desorption temperature, desorption time, extraction time, sample flow, extraction temperature, salt content and agitation were optimized. Dynamic linear range for quantification was calculated between 20-1000 ng L-1 with R2>0.99. Relative standard deviations for sample containing 1mg L-1 for inter-day,intra-day and fiber-to-fiber were calculated and acceptable values (below 13%) wereobtained. LOD in the range of 5-10 ng L-1 were obtained for the method. Finally, hookah were studied as a real sample, as it was assumed it contains organic pollutants in its smoke. Three tobaccos with different flavors (2apples, orange and cinnamon) were used. Water inside hookah was used and pollutants were extracted from it. Toluene was found in the water of 2apples tobacco with concentration of 439(±12) ng L-1. Benzene was also found but it was lower the LOQ, so, quantification can’t be done. Other pollutants werealso found in the smoke and water of hookah
  9. Keywords:
  10. Needle Trap Extraction ; Gas Chromatography ; BTEX ; Superhydrophobic Surfaces ; Environmental Pollutant ; Melamine Formaldehyde Foam ; Aquatic Media

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