Solid phase microextraction techniques for determination of environmental contaminants

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Title: Solid phase microextraction techniques for determination of environmental contaminants
Author: Ding, Yuehang
Contributor: University of Helsinki, Faculty of Science, Department of Chemistry
Thesis level: master's thesis
Abstract: Solid phase microextraction is an analytical chemical technique where a fiber is coated with various extracting phase. By changing the properties of the coating, SPME techniques provide an easy, fast and solvent-free way to analyze distinct matters in different matrix. If the extraction time is long enough to establish the equilibrium, the analytes can be quantified according to basic of thermodynamics and diffusion theory. In the theoretical parts, the author gave a brief introduction of the fundamentals of the SPME technique. The fiber coating is the soul of fiber SPME techniques since the coating material decides the coating method, the choices of the target compounds, and the working condition. Besides, the selection of the commercial fiber is very narrow. Therefore, the author reviewed various types of fiber coatings which are current applied in environmental analysis but made at home or laboratory. IL is an organic salt in liquid phase where organic cations coordinated with organic or inorganic anions. ILs fibers attact researchers' eyes because of their alterable ion moieties and matural solvation interactions which are especially good for analysis of polar compounds. Sol-gel silica fiber is superior due to its coating method (sol-gel) producing unique porsity which enlarges the surface capacity in separation science. MIPs fiber is famous for its molecular recognition which can overcome the shortcomings of the commercial fibers without selectivity. This fiber is suitable for the special extraction which needs high selectivity. Conductive polymers as SPME fibers are hot thanks to their various adsorption mechanism and natural hydrophobicity. Besides, the quality of fiber can be well-controlled by electrochemical coating methods which makes extractions more reproducible. MOF fibers give potential in SPME application attributable to its unique structure where metal ion or metal clusters bonded with organic ligand via coordinative bonds. Through the proper modification, MOF can achieve extreme high selectivity. Nanomaterial SPME fibers combine not only material original advantages but also nanoscale effect. That is the reason for being highlighted. SPME techniques can always couple with GC-MS for quantification of the analytes. The experimental part mainly consists the choices of the working Arrow, optimization of the parameters, validation study and natural sample applications. As a result, PDMS Arrow was proved to provide better selectivity and sensitivity compared to (CAR-1000) and the headspace mode yielded sufficiently high for the PAHs with less than five rings. After analysis, it is found that both influent and effluent water samples were contaminated according to EPA limitation
URI: URN:NBN:fi-fe2017112251552
Date: 2017
Discipline: Analytical Chemistry
Analyyttinen kemia
Analytisk kemi

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