Chemometric Methods Spectroscopy In Rhubarb And Organic Environmental Pollutants, Uv Spectra Retrieval Applications

Rhubarb is a well-known traditional medicinal material used in China as a cathartic and a promoter of gastric health. In the Chinese pharmacopoeia there are only three recorded species, namely, R. palmatum, R. tanguticum and R. officinale, and these are referred to as official rhubarbs. Besides the official rhubarbs, radix and rhizome of other species within the genus Rheum are often used in folkloric medicine in various minority regions. However, the purgative activity of some unofficial rhubarb is much lower than that of the official rhubarb and some may even cause stomach ache. To ensure the safety and curative effectiveness of rhubarb in clinical practice, it is important and necessary to distinguish between official and unofficial rhubarbs.In recent years, many modern instrumental analysis methods have been used in identification and qualification of herbal medicine. Middle infrared (MIR) spectroscopy plays an important part in qualitative and quantitative analyses of herbal medicine. Near infrared spectroscopy (NIR) technique has become a new method of qualitative identification and quantitative analysis of traditional Chinese medicine as a simple, rapid, undestroyed method. Temperature constrained cascade correlation networks (TCCCN) have gained more interests in building the nonlinear models especially for identification of the medicine herbs, because of its faster training rate, greater generalized ability and more robustness.In chapters two and three of this thesis, TCCCN with leave-one-out and Latin-partition cross validation were attempted for classification of the official and unofficial rhubarb samples, respectively, based on MIR, NIR spectra. The parameters of TCCCN were discussed in detail. The results showed that the correctness of TCCCN based on MIR spectra with optimized parameters was 96.13%, and the correctness of TCCCN based on NIR was 100%.The two dimensional correlation between MIR and NIR spectroscopy analysis is expected to provide rich insight and clarification into vibration spectra of complex systems, because of the complementary nature of the two spectroscopic techniques. In chapter four of this thesis, the two dimensional middle infrared - near infrared spectroscopy correlation analysis was attempted to study of official and unofficial rhubarbs. The results showed that the differences of 2D correlation spectra between official and unofficial rhubarb samples were obvious. So the official and unofficial rhubarbs samples were discriminated according to this difference. And then, some 2D correlation bands, for example at 2280-2300 run and at 1750 nm were assigned to H2O and...