| The generalized two-dimensional correlation infrared spectroscopy based on time-resolved IR signals, has been applied to analyze the inter-molecular and intra-molecular interaction. 2D-IR spectra can enhance apparent spectral resolution efficiently and provide information about the specific order of the spectral intensity changes from different functional groups during the measurement from the analysis of the synchronous and corresponding asynchronous spectra. Thus 2D-IR is often looked upon as a useful initial probing tool to aid in the analysis of complex infrared spectra and has received wide applications in the different fields.Six kinds of starch from different kinds of plant origin were identified by two-dimensional correlation infrared spectroscopy in this thesis. Different kinds of starch were similar to each other in 1D-IR spectra but quite different in 2D-IR spectra. Combined with 1D-IR spectra and the secondary derivative IR spectra, the relationships among the different functional groups of starch and their change sequence under thermal interference were revealed by 2D-IR correlation analysis, and the fingerprint features of starch was directly displayed. In this thesis, the identification method of different kind of starch was developed by 2D-IR, and its feasible ability was tested.In the study of thermal stability of cyclodextrin, using 2D-IR correlation analysis method, the changes of cyclodextrin during heating up were discovered. The variable temperature process can be divided into three stages. At 50~150℃, the water of absroption and crystallization was desorbed; 150~250℃, the 1o hydroxyl group was oxidized to carbonyl group by oxygen; over 260℃, cyclodextrin was oxidized intensely, the glyc ring and big ring were destructed, and ultimately CO2 and H2O were engendered. 2D-IR analysis offers a valuable theory gist to the study of thermal stability mechanism of cyclydextrin. |
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