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An Interior Needle Electropolymerized Pyrrole-Based Coating for Headspace Solid-Phase Dynamic Extraction of Chlorophenols

Kamal Abyaneh, Zahra | 2008

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 39422 (03)
  4. University: Sharif University of Technology
  5. Department: chemistry science
  6. Advisor(s): Bagheri, Habib
  7. Abstract:
  8. Nowadays, the inside needle capillary adsorption trap (INCAT) technique as a solventless sample preparation approach and alternative extraction method derived from SPME is gaining rising attentions. The INCAT and needle-trap devices are inexpensive, robust, reusable, and are applicable for sampling and analyzing suitable organic compounds from many different sample matrices. Compared to the fragile silica-based SPME fiber, the needle device is nearly impossible to break mechanically. In addition, the extraction medium possesses quite a large extraction phase volume and a powerful preconcentration capability. Similar to SPME, needle-like devices are particularly convenient for automation and development of on-line procedures. This particular advantage is more pronounced when needle type sampler is compared to mega bore sorbent tubes which generally need an extra heating system for the thermal desorption. In this study a headspace solid-phase dynamic extraction (HS-SPDE) technique was developed using polypyrrole (PPy) sorbent, electropolymerized inside the surface of a needle, as a possible alternative to SPME. Thermal desorption was subsequently, employed to transfer the extracted analytes into the injection port of a GC-MS.
    The PPy sorbent including polypyrrole-dodecyl sulfate (PPy-DS) was deposited on the interior surface of a stainless steel needle from the corresponding aqueous electrolyte by applying a constant deposition potential. The developed technique was applied to the trace level extraction of phenol and five chlorophenols (1-chlorophenol, 2-chlorophenol, 4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol) from water samples. Optimization of influential experimental conditions including the extraction time, the extraction temperature, the peristaltic pump flow rate, the ionic strength and the desorption temperature were also investigated. The detection limits (LOD) of the method under optimized conditions were in the range of 0.15 to 0.4 ng/mL (S/N=3). The relative standard deviations (RSD) were obtained between 2 and 16% (n=5)
  9. Keywords:
  10. Polypyrrole ; Gas Chromatography/Mass Spectrometry (GC/MS) ; Neadle Trap ; Water Samples ; Chlorophenols

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