Synthesis And Applications Of Functionalized Mesoporous Materials In Solid-phase Microextraction

Since the first report on the synthesis of the novel M41S silica mesoporous materials (particularly MCM-41) by Mobil researchers in 1992, a variety of mesoporous materials such as MCM,SBA and MSU has been achieved. Compared with microporous materials, mesoporous materials not only have larger surface area and thicker wall between pores, uniform pore size distribution and huge pore volume, but also they have excellently mechanical and chemical stability. They were widely used in catalysis, separation, nanoscience and biomaterials in the past decade. As a novel inorganic or inorganic/organic functional material, MSU and its functionalized MSU have potential applications in many fields such as sorption, separation and catalysis because of their advantages of structure and property.Solid-phase microextraction (SPME) is a novel solvent-free extraction technique that integrates extraction, concentration and sample introduction in a single step. It has advantages of simplicity, rapid extraction, and easy quantification. SPME could be easily coupled with gas chromatography (GC) and high performance liquid chromatography (HPLC). SPME was successfully applied to extractiion and concentration of various analytes in environmental samples (gas, liquid and solid), foodstuff, biological samples. Fiber coating is the most important part of SPME. The property of coating determines the extraction capacity, sensitivity, selectivity and the resultes of analysis. Currently, the general applications for SPME are devoted to fused silica fibers coated with various polymeric coatings. To improve the sensitivity and selectivity of SPME technique, some novel coatings have been developed as the fiber coatings of SPME. With the development of these novel coatings, the SPME technique has a wide application in extraction and separation.This thesis consists of five parts:Chapter 1 reviews the current state of the art in mesoporous material research and briefly introduces its synthesis according to different channel structure, morphology and derivation. The emphasis is placed on its applications in the fields of adsorption and separation. The current SPME technique and its development of SPME fiber coating were also covered. In Chapter 2, one-pot synthesis of phenyl functionalized MSU (ph-MSU) was performed under alkaline reaction conditions using trimethoxyphenysiliane as a silanized reagent. The synthesized mesoporous composite was characterized by FT-IR, small angle XRD, nitrogen adsorption-desorption, SEM and DTA.In Chapter 3, one-pot synthesis of alkyl functionalized MSU was performed under alkaline reaction conditions using trimethoxyphenysiliane as a silanized reagent. The synthesized mesoporous composite was characterized by FT-IR, small angle XRD, nitrogen adsorption-desorption, SEM and DTA.In Chapter 4, the Ph-MSU was employed as the new fiber coating of SPME coupled with HPLC. The performance of the fiber coating was examined with extraction and desorption time, extraction temperature, stirring rate and ionic strength for determination of PCBs. The linear range, detection limit, recovery and precision were investigated. The results were satisfactory. A rapid, easy, sensitive and precise procedure was established for the determination of PCBs in environmental samples.