The Preparation And Application Of CNTs@SiO₂ And Study On The Finger-Print Of Total Flavniods In Cynomorium Songaricum

In this dissertation, multi-walled carbon nanotubes coated silica microspheres(MWCNTs@Si O2) were synthesized by covalent binding of amido bond. It can be used in solid phase extraction and chromatographic packing materials. Meanwhile, in order to control the quality, the fingerprint of total flavonoids in Cynomorium songaricum was established based on the techniques coupled with macroporous adsorption resin(MAR) and high performance liquid chromatography(HPLC).The main content of this dissertation was carried out by the following several aspects:1. The application of MWCNTs@Si O2 in analytical chemistry especially in chromatographic packing and sample preparated materials were reviewed in this paper. In addition, the chemical component and pharmacological activity of Cynomorium songaricum were elucidated. Furthermore, the chromatographic fingerprint technology used in quality control for traditional Chinese medicine was also summarized.2. The chromatographic columns with different MWCNTs@Si O2 ratios were prepared by covalent binding of amido bond. We investigated the effect of separation conditions on the retention values between aromatic compounds and stationary phases, such as different ratios of methanol and water in mobile phase, column temperatures and flow rates. The results showed that the hydrophobicity of stationary phases was enhanced by coating carbon nanotubes. The column efficiencies were increased from 1418~3545 to 2600~5708 because of π-π conjugate effects of carbon nanotubes. In addition, from the perspective of thermal analysis, due to the addition of carbon nanotubes enhanced the retention of analytes on stationary phase, the arrangements of analytes changed from disordered to ordered. Besides, the retention mechanisms of analytes on different chromatographic columns were not dominated by one single retention mechanism, but by various mechanisms in a coordinated way.3. As a new type of solid phase extraction material, this procedure afforded a convenient, sensitive and accurate method for the simutanious determination of four kinds of nucleic acids and nucleotides in human urine. After optiming the extraction conditions, the enrichment factor of target compounds were improved 3-27 times. Besides, the adsorption mechanisms were also discussed by the studies of adsorption kinetics and adsorption isotherm. Finally, the target compounds in human urine were determined using this method.4. 10 batches of Cynomorium songaricum were collected in main production regions. We have established fingerprint of total flaviond in Cynomorium songaricum by using HPLC.The relative retention time and relative peak were chosen as evaluating indicators. The RSD values of precision, repeatability and stability for nine common peaks were less than 3%, their similarity were between 0.84 and 0.99. The result showed that the established fingerprint conformed to the technical requirements of chromatographic fingerprint for traditional Chinese medicine.The innovations of this dissertation are summarized as three aspects: 1. MWCNTs@Si O2 was synthesized by optimizing optimal synthesized condition, and the separated mechanisms were discussed in details by the theory of kinetics and thermodynamics. 2. It provided a new method to collecting and separating nucleosides and nucleobases compounds by solid phase extraction 3. It is the first time to establishing a HPLC fingerprint for total flavonoid of Cynomorium songaricum and providing a theoretical basis for quality control for total flavonoids in Cynomorium songaricum related productions.