Photo-diode array provides a variety of options to reveal the presence of more than a single substance in a peak. The commonly used approaches are checking the ratio of absorbance at two wavelengths, spectral similarity at upslope and downslope positions, derivative of chromatograms, and variation of time profile maximum at different wavelengths. But the reliability of these methods is affected by small resolution, spectral similarity, drift, and signal to noise ratio. A method of detecting overlapped peaks based on multi-variate analysis of data of LC/UV-Vis diode array detector has been developed to determine the peak purity. It is not required to have an assumption of the peak shape of the chromatogram or spectra of individual components. Pseudo tailing and real tailing elution can be identified easily. / The Raman spectra of the pure crystalline phase and pure amorphous are now well characterized. However, the experimental determination of the Raman spectrum of the interface has been elusive because of the impossibility of having a structure made of these characteristics. A deconvolution by factor analysis of the Raman spectra in the internal mode region of different linear polyethylene covering a wide range of crystallinity content is used in this work in order to generate the Raman spectrum of the interface of a polymeric crystal. / A major hurdle to the rapid development of conductive polymers is the lack of knowledge of the relationship between structure and physical and chemical properties. The analysis of polypyrrole is limited by its insolubility, lack of processability, and opacity. Raman spectroscopy has proved to be an effective technique in measuring opaque or turbid samples whereas conventional IR and UV methods are restricted. In situ Raman scattering has been used to follow the kinetics of the heterogeneous oxidative chemical polymerization of pyrrole. The recently developed fiber optics techniques provide a convenient and flexible approach to in-situ monitoring and circumvent the limitations of experimental conditions such as distance, vibration, size, and temperature. / Source: Dissertation Abstracts International, Volume: 52-12, Section: B, page: 6357. / Major Professor: Charles K. Mann. / Thesis (Ph.D.)--The Florida State University, 1991.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_76561 |
| Contributors | Shen, Chengbo., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 151 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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