The production and distribution of counterfeit drugs is a serious worldwide health problem. One recent example is the appearance of fake artesunate antimalarial tablets in Southeast Asia. Due to the malevolent circumstances in which these fakes are produced, concern over the presence of toxic tablet ingredients is very much a legitimate health issue. Therefore, quantification of the amount of active ingredient present in tablets marketed as artesunate, a drug used for the treatment of the multidrug-resistant Plasmodium falciparum malaria in Southeast Asia required liquid chromatography coupled to mass spectrometry (LC-MS). This quantification allows the classification of the tablets as genuine, sub-therapeutic or fake and the validation of field results using colorimetric tests. During the LC-MS experiments, there were the observations that several of the samples contained a “wrong” active ingredient (AI). This was identified via accurate mass measurements, chromatographic retention time and in-source collision-induced dissociation (CID)as erythromycin, a common antibiotic. Using multivariate unsupervised clustering algorithms, the LC-MS data was utilized for “chemically fingerprinting” the fake tablet samples and investigating the similarities between them. The results of this initial survey show a correlation between sample origin, the different types of fake authentication holograms found in the packaging and sample composition.

In this thesis we synthesize discotic liquid crystal materials. After demonstrating the molecular structures by 1H-NMR of Acid-6, we measure the properties of this material. We use discotic liquid crystal Acid-6 and measure its¡¦ properties. It shows the properties of Acid-6 which is having the ability of absorbing visible light. By UV-Vis spectrum, we can realize the absorption band is located at 400 nm and confirm that it is able to be a photo-sensitized dye. Besides, the property of discotic liquid crystal is the self-assembly ability, the molecular can assemble into hexagonal columnar structure by themselves, which enable discotic liquid crystal to have better mobility. The DSSCs have good power conversion efficiency with using discotic liquid crystals Acid-6. We can measure its¡¦ mobility to know the component with which the most appropriate.

Discotic liquid crystals (DLCs), which consist of disk-like molecules, have recently attracted considerable attention for their interesting electronic properties. One of the most significant of DLCs is their high charge carrier mobility in their columnar structure. Recently the number of researches have been increasing on applications such as organic light-emitting diodes (OLED), photovoltaic devices (OPV) and organic field-effect transistors (OFET). The purpose of the study is to investigate the mobility of different alignment of DLCs. The material used in the present study is HDBP-8. We will show that the stack of DLCs depended on temperature strongly. We will also discuss charge transport properties of homeotropic alignment. Carrier transport has been investigated in the hexagonal columnar (Colh) mesophase of HDBP-8 using time-of-flight (TOF) technique. The carrier mobilities are up to the order of 10-3 cm2V-1s-1 for both positive and negative charges with weak dependence on the electric fields.

In this thesis, we investigated charge carrier properties of two series of organic semiconductors with time of flight measurement. Charge carrier mobility is calculated in different electron filed and fitted to Poole-Frenkel model. In the first part, we investigated carrier properties of pyrrole derivatives .The mea- surement result of pyrrole derivatives with different functional group indicate that trans- port properties may effected by this different functional group and the bonding position. There have two different type of transport properties that is single transport and bipolar transport. In addition, carrier mobility have more than two order difference with this different functional group. Finally, we investigated carrier properties of anthracene derivatives. The measure- ment result indicate that the intermolecular aggregation can be solved by synthesizing another functional group to form polymer. This method not only perform excellent thin film stability but also keep bipolar transport property after synthesizing.

This study focuses on the application of 193-nm excimer laser (ArF) photodissociation to tandem time-of-flight mass spectrometry. In particular, it focuses on identifying the optimal experimental conditions for peptide sequencing and applying the technology to interesting systems. The early focus is on optimizing the sample preparation conditions that define the initial internal energy state of MALDI-produced ions. Subsequent chapters investigate the effect of changing photodissociation laser conditions and define conditions under which the information content of the spectrum is maximized. Later chapters compare the photodissociation experiment to technologies that represent the current state of the art in tandem mass spectrometry, illustrating both the advantages and shortcoming of photodissociation TOF methodology. Finally, we apply photodissociation to the study of interesting systems of biological relevance, including (1) peptides derived from enzymatic digestion, (2) post-translationally modified peptides, and (3) peptide-transition metal ion complexes. In the final chapter we consider the analytical implications of the work as a whole and comment on the analytical viability of the methodology and look forward to new directions for the experiments.

The construction of a liquid nitrogen-cooled ion mobility spectrometer coupled with time-of-flight mass spectrometry was implemented to demonstrate the ability to discriminate between electronic isomers. Ion mobility allows for the separation of ions based on differing cross-sections-to-charge ratio. This allows for the possible discrimination of species with same mass if the ions differ by cross-section. Time-offlight mass spectrometry was added to mass identify the separated peak for proper identification. A liquid nitrogen-cooled mobility cell was employed for a two-fold purpose. First, the low temperatures increase the peak resolution to aid in resolving the separated ions. This is necessary when isomers may have similar cross-sections. Second, low temperature shortens the mean free path and decreases the neutral buffer gas speeds allowing for more interactions between the ions and the drift gas. Kr2+ study was performed to verify instrument performance. The variable-temperature ion mobility spectrometer was utilized to separate the distonic and conventional ion forms of CH3OH, CH3F, and CH3NH2 and to discriminate between the keto and enol forms of the acetone radical cation. Density functional theory and ab initio calculations were employed to aid in proper identification of separating isomers. Monte Carlo integration tools were also developed to predict ion cross-section and resolution within a buffer gas.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references. Also available on the Internet.

Thesis (Ph. D.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains ix, 99 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

Thesis (Ph. D.) in Physics--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 153-158).