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Strategies for chemometric analysis of gas chromatographic data /Johnson, Kevin J., January 2003 (has links)
Thesis (Ph. D.)--University of Washington, 2003. / Vita. Includes bibliographical references (leaves 145-155).
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Simultaneous Part-Per-Billion Determination of Sodium and Chloride IonsGan, Din-Chung 08 1900 (has links)
The method utilizes both cation and anion concentrator columns in parallel as a preconcentration system. The preconcentrator system is loaded using a reagent delivery module operated for a specific time at a preset flow rate. Total injection volumes of 2-5 ml are routinely used. Various chromatograms are discussed along with detailed information concerning detection limits for sodium and chloride, the system operating conditions, and the solutions to other pitfalls which have arisen during the course of this work.
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Optical Properties and Chemical Composition of Secondary Organic AerosolKameel, Fathima R. 21 April 2009 (has links)
No description available.
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Process development for downstream processing of human growth hormone and its antagonistZheng, Yizhou January 1994 (has links)
No description available.
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Multivariate Statistical Methods Applied to the Analysis of Trace EvidenceSzkudlarek, Cheryl Ann 22 August 2013 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The aim of this study was to use multivariate statistical techniques to: (1) determine the reproducibility of fiber evidence analyzed by MSP, (2) determine whether XRF is an appropriate technique for forensic tape analysis, and (3) determine if DART/MS is an appropriate technique for forensic tape analysis. This was achieved by employing several multivariate statistical techniques including agglomerative hierarchical clustering, principal component analysis, discriminant analysis, and analysis of variance. First, twelve dyed textile fibers were analyzed by UV-Visible MSP. This analysis included an inter-laboratory study, external validations, differing preprocessing techniques, and color coordinates. The inter-laboratory study showed no statistically significant difference between the different instruments. The external validations had overall acceptable results. Using first derivatives as a preprocessing technique and color coordinates to define color did not result in any additional information. Next, the tape backings of thirty-three brands were analyzed by XRF. After chemometric analysis it was concluded that the 3M tapes with black adhesive can be classified by brand except for Super 33+ (Cold Weather) and Super 88. The colorless adhesive tapes were separated into two large groups which were correlated with the presence of aluminosilicate filler. Overall, no additional discrimination was seen by using XRF compared to the traditional instrumentation for tape analysis previously published. Lastly, the backings of eighty-nine brands of tape were analyzed by DART/MS. The analysis of the black adhesive tapes showed that again discrimination between brands is possible except for Super 33+ and Super 88. However, now Tartan and Temflex have become indistinguishable. The colorless adhesive tapes again were more or less indistinguishable from one another with the exception of Tuff Hand Tool, Qualpack, and a roll of 3M Tartan, which were found to be unique. It cannot be determined if additional discrimination was achieved with DART/MS because the multivariate statistical techniques have not been applied to the other instrumental techniques used during tape analysis.
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Avaliação dos níveis de concentração e identificação de fontes de hidrocarbonetos na Bacia do Alto Iguaçu: estudo de caso pós derrame acidental de óleo na refinaria Presidente Getúlio VargasGallota, Fabiana Dias Costa 02 May 2016 (has links)
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GALLOTTA_30_06_14.pdf: 62695484 bytes, checksum: 33335ee3affc2bcffb11fc10caf9ae3f (MD5) / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências-Geoquímica. Niterói, RJ / Os hidrocarbonetos presentes no ambiente consistem em misturas complexas de
compostos derivados de múltiplas fontes. Os combustíveis fósseis representam a
principal contribuição, devido à taxa e escala espacial, em que o petróleo tem sido
usado como fonte de energia e matéria-prima para a indústria química. O objetivo
deste estudo foi avaliar os níveis de concentração e identificar fontes de
hidrocarbonetos na Bacia do Alto Iguaçu e, em especial, na área de influência da
Refinaria Presidente Getúlio Vargas (REPAR). Além dos fatores de poluição crônica,
a área de estudo foi alvo de um derrame acidental de petróleo em julho de 2000.
Diversos indicadores em diferentes compartimentos ambientais (água superficial,
sedimento, solo e água subterrânea) foram avaliados na fase pós-derrame e no
monitoramento ambiental ao longo de várias campanhas por mais de uma década.
Os esforços de avaliação foram concentrados nos seguintes indicadores: os nalcanos,
os alcanos isoprenoides, os hidrocarbonetos policíclicos aromáticos (HPA),
os biomarcadores de petróleo e ainda o total de hidrocarbonetos de petróleo (THP).
Os resultados identificaram como principal aporte de matéria orgânica para as águas
superficiais dos rios Barigüi e Iguaçu, os fluxos materiais originados em região a
montante do acidente, refletindo a contribuição antropogênica crônica da cidade de
Curitiba. Em 2007 e 2008, as concentrações de THP e HPA nas águas superficiais e
sedimentos dos rios Barigüi e Iguaçu refletem uma expressiva melhoria nas
condições desses rios em relação a 2000. Na área interna da refinaria (Ponto Zero),
observou-se uma nítida diminuição (atenuação) natural das concentrações de THP
no solo em todas as profundidades dos perfis amostrados ao longo do tempo nos
Banhados 1 e 4 e, em particular, uma diminuição importante das concentrações
entre 2004 e 2007. Para a identificação das fontes de hidrocarbonetos foram
utilizadas razões diagnósticas e quimiometria. As razões diagnósticas calculadas a
partir de concentrações de HPA sugeriram que, na maioria dos sedimentos dos Rios
Barigüi e Iguaçu coletados nas campanhas de 2000 e 2001, a fonte petrogênica é a
principal. Somente na estação a montante do acidente no Rio Barigüi, a fonte
pirolítica predominou nestas duas campanhas. As razões diagnósticas que
apresentaram maior eficiência na identificação de fontes de hidrocarbonetos nos
sedimentos dos rios Barigüi e Iguaçu foram: ΣC1-Fenantrenos/Fenantreno; e (ΣHPA
parentais de 3-6 anéis)/(Σ5 séries de HPA alquilados). A identificação de fontes
através de razões diagnósticas calculadas a partir de áreas e alturas de picos
cromatográficos demonstrou sua aplicabilidade verificando a relação entre os
compostos encontrados em amostras de solo da área interna da refinaria com a
amostra de petróleo derramado no acidente, após quase uma década da ocorrência
do vazamento. A identificação de fontes através método de quimiométrico baseado
na análise de componentes principais (ACP) de seções pré-processadas e
combinadas dos Cromatogramas de Íons Selecionados (CIS) mostrou que as
amostras mais contaminadas estão na área interna da refinaria. Essas amostras
apresentam um padrão de distribuição petrogênica e diferentes graus de
intemperismo. As amostras da área externa à refinaria (Guajuvira, General Lúcio e
Balsa Nova) são menos ou não contaminadas e/ou contém uma mistura de
contribuições diagenéticas, pirolíticas e petrogênicas onde predominam diferentes
proporções. Os locais mais distantes da atividade industrial (Balsa Nova) contem,
como esperado, os níveis mais baixos de contaminação por HPA. Os resultados de
biomarcadores demonstraram que não há evidências para concluir que as amostras
da área externa à refinaria e o óleo Cusiana vazado tenham a mesma origem. Os
resultados ao longo dos rios Barigüi e Iguaçu e do Ponto Zero demonstraram que as
ações de emergência para a contenção do óleo foram adequadas para os rios, e que
a contaminação decorrente do derrame ficou predominantemente contida no Ponto
Zero e diminuiu significativamente após uma década. / Hydrocarbons present in the environment consist of complex mixtures of compounds
derived from multiple sources. The main contribution lies on fossil fuel inputs due to
the rate and spatial scale by which petroleum has been used as an energy source
and chemical feedstock. The aim of this study was to assess the concentration levels
and identify sources of hydrocarbons in the Upper Iguaçu Watershed and, in
particular, in the area of influence of the President Getulio Vargas Refinery (REPAR).
In addition to the factors of chronic pollution, the study area was the scenario of an
acute accidental oil spill in July 2000. Numerous indicators in different environmental
compartments (surface water, sediment, soil and groundwater) were assessed in the
post spill phase and during the environmental monitoring programs over the course
of several campaigns for more than a decade. Assessment efforts were concentrated
on the following indicators: n-alkanes, alkanes isoprenoids, polycyclic aromatic
hydrocarbons (PAH), petroleum biomarkers and total petroleum hydrocarbons (TPH).
The results identified as the main contribution of organic matter to surface waters of
the Barigüi and Iguaçu Rivers the materials flows originated in the region upstream of
the accident, reflecting chronic anthropogenic contribution of the city of Curitiba. In
2007 and 2008, the TPH and PAH concentrations in surface waters and sediments of
the Barigüi and Iguaçu Rivers revealed a significant improvement in the conditions of
these rivers when compared with 2000. Inside the refinery area (Point Zero), it was
observed a clear natural decrease (attenuation) of the concentrations of TPH in the
soil at all depths sampled over time in Marshes 1 and 4 and, in particular, an
important decrease of concentrations between 2004 and 2007. Diagnostic ratios and
chemometrics were used to identity hydrocarbon sources. The diagnostic ratios
calculated from the concentrations of PAH suggested that, in the majority of
sediments from the Barigüi and Iguaçu Rivers collected in 2000 and 2001
campaigns, the main source is petrogenic. Only in the station upstream the accident
in the Barigüi River, the pyrolytic source predominated in these two campaigns. The
diagnostic ratios that presented higher efficiency in identifying sources of
hydrocarbons in sediments of the Barigüi and Iguaçu Rivers were: ΣC1-
Phenantrenes/Phenanthrene; and (Σ3-6 rings parental PAH)/(Σ5 alkylated PAH
series). The source identification through diagnostic ratios calculated from heights
and areas of chromatographic peaks demonstrated its applicability establishing a
relationship between the compounds found in soil samples of the internal area of the
refinery and the sample of the oil spilled in the accident, after nearly a decade of
occurrence of the spillage. The source identification through chemometric method
based on principal components analysis (PCA) of preprocessed and combined
sections of Selected Ion Chromatograms (SIC) showed that the most contaminated
samples are inside the refinery area. These samples present a petrogenic pattern
and different weathering degrees. Samples from outside the refinery area (Guajuvira,
General Lúcio e Balsa Nova) are either less or not contaminated, and/or contain
mixtures of diagenetic, pyrogenic and petrogenic inputs where different proportions
predominate. The locations farthest away from industrial activity (Balsa Nova)
contain, as expected, the lowest levels of PAH contamination. The biomarkers results
do not show any evidences to conclude positive matches between the samples from
outside the refinery area and the spilled Cusiana oil. The results along Barigüi and
Iguaçu rivers and Point Zero demonstrated that emergency actions to contain the oil
were appropriate for the rivers, and that the contamination resulting from the spill was
mostly contained in the Point Zero and decreased significantly after one decade
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