| The dissertation focuses on the studies of cryogenic fluorescence spectrometries and their combination with various fluorescence techniques for the direct or simultaneous determination of polycyclic aromatic hydrocarbons (PAHs) in the environment. The dissertation consists of four chapters.In the first chapter, the development of cryogenic fluorescence techniques was reviewed. Various cryogenic fluorescence spectrometries(especially the Shpol'skii spectroscopy) theoretical principle of the Shpol'skii effect the coupling between cryogenic fluorescence techniques and other analytical techniques and their application for the analysis of PAHs in the environment were described in detail. At last, the plans for the whole dissertation were put forward. This chapter was divided into five sections.In the second chapter, an instrumental system for the low-temperature measurements was developed,which was realized through a spectrofluorimeter combined with a cryo-unit system connected by optical fibers. In addition, a new sample cell was designed to meet the requirement for the qualitative and quantitative analysis and the factors (including monochromator bandpass Shpol'skii solvent matrix concentration effect cooling rate) that influence the Shpol'skii spectra were discussed. Finally, the procedure of the preparation for the frozen samples was determined.In the third chapter, a method that can determine the PAHs in the realsamples by utilizing Shpol'skii effect coupled with constant wavelength synchronous fluorescence (CWSF) spectrometry was described. The method can gain high resolution and reduce the spectral interference more effectively. This chapter was divided into two sections.In the first Secton, the direct determination of Benzo[a]pyrene in the environmental samples was introduced. Benzo[a] pyrene is the typical polycyclic aromatic compound among the PAHs which can cause cancer and is regarded as the marker as the level of contamination in the environment. Compared with the spectra at the room temperature, the cryogenic constant wavelength synchronous fluorescence spectra showed the superiority much more at the aspects of reducing the spectral interference and the background signal. With the optimal value(14 nm) and the Shpol'skii matrix(n-Octane), the Benzo[a] pyrene in the real samples (tap water sea wate waste water and soil of the factory) was determined directly by this method. The recoveries were above 85%In the second section a method of simultaneous determination of two substances (Coronene and 3.4,8.9-Dibenzopyrene) in the synthetic samples was described by using the shpol'skii effect combined with CWSF. The CWSF spectra of Coronene and 3.4,8.9-Dibenzopyrene overlap badly with each other, which results in the difficulty in identifying them at the room temperature. However, the cyrogenic CWSF spectra of this two substances in the mixture(n-Octane being the common Shpol'skii matrix) can be separated and determined simultaneously due to the Shpol'skii effect plus optimal value(138 ran). The method has been applied to the determination of these two substances in the synthetic samples. The recoveries were above 88% and 80% for the Coronene and 3.4,8.9-Dibenzopyrene respectively.In the forth chapter, two novel techniques were suggested, cryogenic non-linear variable-angle synchronous fluorescence spectroscopy and cryogenic derivative fluorescence spectroscopy, which haven't been reported yet in the literature. This chapter was separated into two parts.In the first part, the feasibility of the cryogenic non-linear variable-angle synchronous fluorescence was studied. This method made full use of the high resolution capability of the ShpoFskii effect and the flexibility of the non-linear variable-angle synchronous fluorescence, and would facilitate the analysis for the PAHs in the complexity. After checking out the cryogenic contour maps of the four substances carefully, we obtained the optimal detection route. By using cryogenic non-linear variable-angle synchronous fluoresc...
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