Made available in DSpace on 2014-10-09T12:30:45Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:02Z (GMT). No. of bitstreams: 1 01366.pdf: 2764676 bytes, checksum: eb0ee3f52111d5d6caca21c0dc82fd30 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:30:45Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:01:02Z (GMT). No. of bitstreams: 1 01366.pdf: 2764676 bytes, checksum: eb0ee3f52111d5d6caca21c0dc82fd30 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:42:31Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:09Z (GMT). No. of bitstreams: 0 / A ampla utilização de medicamentos, a falta de gerenciamento na produção e no descarte desses produtos, bem como a dificuldade na remoção de resíduos de fármacos das águas residuais durante as fases do tratamento de efluentes tem causado a liberação destes micropoluentes nos recursos hídricos. O cloridrato de fluoxetina, conhecido comercialmente como Prozac®, tem sido muito utilizado em diversos países. Estudos demonstram sua presença no meio ambiente e o potencial de danos que este fármaco pode causar à biota. Desta forma, este trabalho estudou uma tecnologia de tratamento (POA - Processo Oxidativo Avançado) utilizando-se radiação ionizante, proveniente de um acelerador de elétrons, para a degradação do fármaco cloridrato de fluoxetina em solução aquosa e na mistura com esgoto doméstico. Após a irradiação foram feitas análises químicas na solução aquosa do fármaco com Espectrofotometria UV/VIS, Cromatografia Líquida Ultra Rápida (detectores UV/VIS e fluorescência) e quantificação do Carbono Orgânico Total (COT). Também foram empregados ensaios de toxicidade aguda (Daphnia similis e Vibrio fischeri) e crônica (Ceriodaphnia dubia). A eficiência na degradação do fármaco foi superior a 98,00% na menor dose de radiação (0,5 kGy), porém houve baixa taxa de mineralização para as doses aplicadas neste estudo. Para a Daphnia similis na dose de 0,5 kGy houve eficiência de 83,75% na redução da toxicidade do cloridrato de fluoxetina e 87,24% para 5,0 kGy, houve eficiência de 100,00% na redução da toxicidade para o esgoto doméstico e para a mistura (CF + esgoto) 79,32% na dose de 5,0 kGy. A eficiência para a Vibrio fischeri foi de 17,26% (melhor eficiência na dose de 5,0 kGy) e após a correção do pH das amostras a melhor eficiência foi para 20,0 kGy (26,78%), para o esgoto e para a mistura as eficiências ficaram em torno dos 20,00% para todas as doses de radiação aplicadas. Em relação a toxicidade crônica para Ceriodaphnia dubia a eficiência foi de 97,50% para 5,0 kGy. Verificou-se que a Ceriodaphnia dubia possui maior sensibilidade ao fármaco, seguido da bactéria Vibrio fischeri e por fim a Daphnia similis. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

An extensive study of disubstituted cycloalkanes like CnH2n where n=3,4,5 and 6 using DFT((U)B3LYP/6-31G(d) and 6-311+G(2df,2p)) calculations is presented focusing on the effect of pyramidalization of the radical center. A potential energy surface (PES) analysis shows that the radical prefers to pyramidalize anti to the two cis fluorines in the disubstituted cycloalkanes. The degree of pyramidalization for 1,2-difluorocyclopropyl radical is 43.9o away from the cis fluorines whereas for 1,3-difluorocyclobutyl radical, 1,3-difluorocyclopentyl radical and 1,3-difluorocyclohexyl radical is 3.8o, 5.4o and 14.5o respectively away from the cis fluorines. The importance of this pyramidality effect in these compounds is discussed in context with the carbon-hydrogen bond dissociation energies (BDE's) because the preference of the radical centers to pyramidalize anti to the fluorines affects the bond dissociation energy. Importance of steric effect and unfavorable electronic interactions have been extensively explored in planar permethylated cyclobutadiene (Me4CBD) and cyclooctatetraene (Me8COT) using ((U)B3LYP/6-31G(d) and 6-311+G(2df,2p)) calculations. It is thought that steric interactions dominate electronic interactions in Me8COT, while this works opposite in case of Me4CBT. Instead, in Me4CBD the number of unfavorable electronic interactions between π bonds and out-of-plane hydrogens plays the dominant role in determining the relative energies. Interactions between the π bonds of CBD and the out-of-plane hydrogens on carbons attached to the four-membered ring becomes very interesting when the ring size changes. With ethano bridge on the cyclobutadiene ring interaction with the diagonal bonds results in non-bonding AOs across the other diagonal having the opposite phase in the highest occupied (HO)MO. If the HOMO and LUMO are switched, bis-ethano-bridged tetrahedrane is formed. It is suggested that bis-ethano-bridged tetrahedrane is thermodynamically more stable than bis-ethano-bridged cyclobutadienes. While the reverse is true for unsubstituted cyclobutadienes. The ability of ethano bridges to reverse the usual order is because it causes the doubly-bonded carbons to pyramidalize.

Made available in DSpace on 2014-10-09T12:42:31Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:02:09Z (GMT). No. of bitstreams: 0 / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

The development of analytical methods for emerging contaminants creates many unique challenges for analytical chemists. By their nature, emerging contaminants have inherent data gaps related to their environmental occurrence, fate, and impact. This dissertation is a compilation of three studies related to method development for the structural identification of emerging contaminants, the detection and quantification of chemicals used in unprecedented quantities and applications, and the extraction of compounds from complex matrices where the solvent-solute-matrix interactions are not completely understood. The three studies present analytical methods developed for emerging contaminants in complex matrices, including: fluorochemical surfactants in aqueous film-forming foams, oil dispersant surfactants in seawater, and fullerene nanomaterials in carbonaceous solids. Aqueous film-forming foams, used in military and commercial firefighting, represent environmentally-relevant commercial mixtures that contain a variety of fluorochemical surfactants. Combining the surfactant-selective ionization of fast atom bombardment mass spectrometry with high resolution mass spectrometry, chemical formulas for 11 different fluorochemical classes were identified. Then AFFF-related patents were used to determine the structures. Of the eleven classes of fluorochemicals, ten have little, if any, data on their environmental occurrence, fate, and potential impacts in the peer-reviewed literature. In addition, nine of the identified classes had either cationic or zwitterionic functionalities and are likely to have different transport properties compared to the well-studied anionic fluorochemicals, such as perfluorooctanoate. After the Deepwater Horizon oil spill in the summer of 2010, one of the emergency response methods for the mitigation of the oil's environmental impact was the use of unprecedented amounts of oil dispersant to break down the oil slick and encourage biodegradation. This event illustrated the need for rapid analytical method development in order to respond to the potential environmental disaster in a timely manner. Using large volume injection liquid chromatography with tandem mass spectrometry, an analytical method was developed for the trace analysis of the multiple dispersant surfactant classes and the potential degradation products of the primary surfactant. Limits of detection ranged from 49 ��� 3,000 ng/L. The method provided excellent recovery (86 ��� 119%) and precision (10 ��� 23% RSD), while also accommodating for the high salinity of seawater samples and analyte contamination. Despite the fact that fullerene nanomaterials have been studied for almost three decades, research is still being conducted to fully understand the environmental properties of these materials. Previous studies to extract fullerenes from environmental matrices have resulted in low efficiency, high variability, or the extraction efficiencies have gone unreported. Extraction by ultrasonication with toluene and 1-methylnaphthalene increased the recovery 5-fold of a spiked, isotopically-labeled C������ surrogate from carbon lampblack as compared to that of the conventional approach of extracting with 100% toluene. The study revealed the importance of evaluating experimental variables such as extraction solvent composition and volume, and sample mass, as they have a significant impact on the quantitative extraction of fullerenes from environmental matrices. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from Aug. 15, 2012 - Aug. 15, 2013