Applications Of Novel Chemometric Models To Quntitative Fluorescence Spectroscopy And Liquid Chromatography-mass Spectrometry

During quantitive analysis of complex systems using spectroscopic intruments and gass/liquid chromatography-mass spectrometry, the data recorded contains not only the concentration information of the analytes of interest but also interfering signals caused by the variations in samples'physical properties, measurement conditions, and background intereferences as well. When measurements are subject to the changes and variations mentioned above, methods for the correction and mitigation of interfering effects are needed to prevent degradation in the accuracy and reliability of multivariate calibration models. To address this issue, our research group proposed an advanced quantitave fluorescence model (QFM) for quantitative flourescence spectroscopy and a multiplicative effects model for mass spectrometry (MEMMS), respectively. In this thesis, the two novel models have been combined with flourescence spectroscopy and liquid chromatography-mass spectrometry to realize accurate quantitative analysis of analytes of interest in complex samples. The main contents of this thesis include the following aspects:In Chapter 2, the influence of scatterers and absorbates in suspension systems on the shape and intensity of fluorescence spectrum of ratiometric fluorescence indicator was investigated in detail. The QFM model was tentatively applied to the correction of the effects of scatterers and absorbers on fluorescence spectra of cell lysates with a view to realize direct quantitative fluorescence analysis of DNA in cell lysates. The method developed in this chapter has the advantages of rapidness, simplicity, high precision and accuracy. It has the potential to be developed into a promising alternative for accurate quantification of genomic DNA.In Chapter 3, a intensity-based fluorescent probe with high selectivity for aluminum ion was synthesized. A generalized ratiometric fluorescence probe for the quantitatification of aluminum ion was designed by combining the intensity-based fluorescent probe with an inert fluorescence dye. With the aid of QFM model, the generalized ratiometric probe was successfully applied to the direct quantitative analysis of aluminium ion in water samples collected from Peach Lake without any pretreatment.In Chapter 4, the experimental investigation was carried out on the influence of ionization efficiency and background impurities on the signal intensity in quantitative LC-MS analysis. The MEMMS model was adopted to mitigate the detrimental effects of ionization efficiency and background impurities, and hence achieved simutaneous accurate quantification of caffeine and three kinds of catechins in biluochun tea.