Development Of Raman Spectrometer And Its Spectroscopy Pretreatment

Raman spectroscopy is a kind of non-intruding technology arising from Raman scattering effect. It can be used to analyze sample's composition and structure. Recently, for its non-destructive, rapid, green and real-time advantages, Raman spectroscopy has become a research focus in the field of analytical chemistry. This thesis reviewed the application techniques of Raman spectroscopy and developed a low-cost Raman spectroscopy analyzer. The main contents of this thesis are as follows:1. Review the development and application of Raman spectroscopy analytical technology;discuss the theory background, detail modeling steps and current application situation of Raman spectroscopy.2. Develop a portable Raman spectrometer independently. For a set of test samples, experiment results show that the analyzer performs satisfactorily on the resolution, precision and stability.3. To overcome the limitations of existing wavelet transform (WT) preprocessing methods for Raman spectra, two novel preprocessing method - WT frequency component stepwise selection algorithm and WT frequency component correlative selection algorithm - were proposed. Experimental results show that application of new algorithms obviously improves the prediction performance of Partial Least Square (PLS) model, comparing with existing pretreatment methods.4. Gasoline Raman spectra were obtained using our new spectrometer, and effective preprocessing method combined with PLS model was applied to predict its octane number. Experiment results show that Raman spectroscopy is feasible to determine gasoline's octane number.