| Recently, the application of nanoparticles in separation, especially in capillary electrophoresis, has attracted much attention of researchers. It attributed to the special properties of the nanoparticles such as large specific surface area, high stability, easy for functionalization and so on. To study the application of nanoparticles in capillary electrochromatography (CEC), the following major innovative researches which were developed at Ph.D. level (three years) were carried out in this thesis on the basis of the previous works.1. A novel MIL-100(Fe) coated open tubular capilalry column was successfully prepared with an in situ, layer-by-layer self-assembly approach for the first time. This novel coating capilalry was used to separae four neutral organic molecules, four basic organic molecules and three acidic organic molecules successfully in CEC.2. A novel graphene oxide (GO) coated capillary column was successfully prepared by grafting the GO nanoparticles on the inner wall of the capillary. Four kinds of neutral oragnic molecules, five basic organic molecules and four acidic organic molecules were baseline separated with this novel GO-capillary.3. Cu3(BTC)2 was grafted on the inner wall of the capillary by covalent bonds for the first time. Through a controlled method, series of capillary columns with different coating thickness were prepared. The separating property of these coating capilalry was tested with four alkylbenzenes.This dissertation consists of six chapters.Chapter 1:The application of nanoparticles in capillary electrophoresis were reviewed especially as stationary phase in CEC.Chapter 2:An open tubular capillary column coated with MIL-100(Fe) nanoparticles was successfully synethesised through an in situ, layer-by-layer self-assembly approach. The results of scanning electron microscope (SEM), fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD), and inductively coupled plasma atomic emission spectrometry (ICP-AES) indicated that MIL-100(Fe) was successfully grafted on the inner wall of the capillary. Four kinds of neutral organic molucles were separated with different cycles coating capillary. The results indicated that the neutral analytes could be separated completely with 10 cycles coating capillary (10-LC), instead of 3,5,15 and 20 cycles coating capillary. Except for that, three acidic organic molucles and four basic orgainc molucles were also baseline separated with the 10-LC. The selectively of the apertures size of MIL-100(Fe), the hydrophobic and electrostatic interactions between the analytes and the solid phase were the main separating mechanism. The stability of the coated capillary were also studied. Taking 10-LC as an example, it could be used for more than 150 times with no obviously changes of the separating efficiency.Chapter 3:A novel coated capillary was prepared by immobilising GO on the fused-silica capillary. The coated capillary columns were characterized by streaming potentials (SPs), SEM and fluorescence microscope. The results indicated that GO sheets was successfully gragted on the inner wall of the capillary. The new GO-capillary is employed to separate a series of neutral, basic and acidic orgainc molecules by CEC mode. The results illustrated that the separating property of the coating capillary was improved greatly and some neutral, basic and acidic orgainc molecules were separated successfully with this novel GO-capillary.Chapter 4:A series of capillary columns coated with Cu3(BTC)2 nanoparticles by covalent bond were synthesised in a controlled way. The results of SEM, XRD and ICP-AES indicated that Cu3(BTC)2 was successfully grafted on the inner wall of the capillary. The separating performance of 3,5,10,15,20 and 25 layers coating capillary were studied with four neutral small organic molecules. The results indicated that,10,15 and 20 layers coating capillary can successfully separate the analytes. But for 3,5 and 25 layers coating capillary, the analytes cannot be separated successfully.Chapter 5:Conclusion. |
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