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Resorcinol-Formaldehyde Xerogel for Analysis of Environmental Pollutant in Aqueous Sample

Zare, Maryam | 2013

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 45197 (03)
  4. University: Sharif University of Technology
  5. Department: Chemistry
  6. Advisor(s): Bagheri, Habib; Es-haghi, Ali
  7. Abstract:
  8. In this study, a new resorcinol-formaldehyde xerogel was synthesized based on sol-gel technology and employed as a sorbent for micro solid phase extraction (µ-SPE) of BTEX and some selected pesticides from aqueous samples.
    In the first part, a µ-SPE method in combined with headspace solvent microextraction (HS-SME) along with gas chromatography- mass spectrometry detection (GC–MS) was developed for the analysis of BTEX in aqueous samples. In our knowledge, this is for the first time that these two different extraction methods has been coupled to maximize the advantage of each extraction method. Influential parameters such as the peristaltic pump flow rate, extraction volume, extraction time, extraction temperature and drop hanging time were optimized.
    Under the optimized conditions, a detection limit range of 0.03-0.1 µg L-1 was obtained. The linear range was obtained in the range of 0.1 to 100 µg L-1 with correlation coefficient of greater than 0.99. The RSD% value at three concentration levels was lower than 8%. The enrichment factor (EF) of the coupled system was found to be higher than HS-SME. The optimized method was applied to the determination of BTEX in Zayenderood and paddy water samples while accuracy and matrix effect were also studied.
    In the second part, the novel sol-gel based µ-SPE sorbent was employed for preconcentration of some selected pesticides. Three pesticides from aryloxy phenoxy propioniate group including clodinafop propargyl, haloxyfop and fenoxaprop-p-ethyl were extracted from aqueous samples by µ-SPE and subsequently determined by GC-MS. Effect of different parameters influencing the extraction efficiency of these pesticides including the peristaltic pump flow rate, sample volume and extraction time were optimized. Under optimum conditions a linear calibration curve in the range of 0.10-500 ng L−1 with R2 > 0.99 were obtained. The RSD% for samples at 50 µg L-1 level was lower than 10% (n=5) and detection limits were between 0.05 and 0.20 µg L-1. The optimized method was successfully applied to the sampling of Pesticides from the Zayende rood and paddy water samples
  9. Keywords:
  10. Solid Phase Extraction ; Mass Spectrometery ; BTEX ; Headspace-Single Drop Microextraction ; Resorcinol-Formaldehyde Xerogel ; Gas Chromatography/Mass Spectrometry (GC/MS) ; Headspace Solvent Microextraction ; Herbicides

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