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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Molecular breeding of functional spinaches rich in folate and betacyanin based on metabolome analysis / メタボローム解析に基づく葉酸及びベタシアニン富化機能性ホウレンソウの育種

Ohtani, Yuta 23 March 2020 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第22487号 / 農博第2391号 / 新制||農||1076(附属図書館) / 学位論文||R2||N5267(農学部図書室) / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 植田 充美, 教授 梅澤 俊明, 教授 栗原 達夫 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
2

Towards more selective sorbents for extraction of drugs and biomarkers from biological fluids using molecularly imprinted polymers

Moein, Mohammad Mahdi January 2014 (has links)
Sample preparation has a critical role as a first step in analytical processes, especially in bioanalysis and environmental analysis. A good sample preparation technique should be robust and stable, regardless of the sample matrix. The aim of this thesis is to design and synthesize molecularly imprinted polymers that can be used in various sample preparation techniques, such as on-line MEPS, on-line SPE and on-line monolithic pre-columns used for the extraction of drugs, hormones, and cancer biomarkers from human plasma and urine samples. Additional aim was to provide full automation, on-line coupling, short sample preparation time and high-throughput. In this thesis MIP in MEPS was used on-line with liquid chromatography-tandem mass spectrometry (LC/MS/MS) for the determination of sarcosine in human urine and plasma samples. The method was fully automated and the packed sorbent could be used for about hundred extractions. In additional work a coated needle with MIP-Sol-Gel as thin layer was prepared and used for the microextraction of bilirubin from human plasma and urine. Small sample volumes could be handled and the validation of the method showed that the method was robust and selective. In a further work MIP-SPE on-line with HPLC was used for the extraction and determination of dextromethorphan in human plasma samples. MIP-SPE showed a good selectivity and high recovery (87% - 92%). On-line MIP monolithic pre-column was prepared and used in a coupled system for the extraction of tramadol in human plasma and urine samples. The MIP monolithic pre-column showed good selectivity and high extraction recovery was obtained (91-96%). The extraction and analysis of human insulin in plasma and pharmaceutical formulation solutions were carried out using MIP-SPE on-line with HPLC. The validation of the method showed that the method was accurate and robust. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 5: Submitted.</p>
3

Pore Size Characterization of Monolithic Capillary Columns Using Capillary Flow Porometry

Fang, Yan 25 September 2009 (has links) (PDF)
A simple capillary flow porometer (CFP) was assembled for pore structure characterization of monolithic capillary liquid chromatography columns based on ASTM standard F316-86. Determination of differential pressures and flow rates through dry and wet samples provided the necessary information to determine the through-pore throat diameter, bubble point pore diameter, mean flow pore diameter, and pore distribution. Unlike measurements in bulk using traditional techniques to provide indirect information about the pore properties of monolithic columns, monoliths can be characterized in their original chromatographic forms with this system. The performance of the new CFP was first evaluated by characterizing the pore size distributions of capillary columns packed with 3, 5, and 7 µm spherical silica particles. The mean through-pore diameters of the three packed columns were measured to be 0.5, 1.0 and 1.4 µm, which are all smaller than the pore diameters calculated from a close-packed arrangement (i.e., 0.7, 1.1 and 1.6 µm), with distributions ranging from 0.1 - 0.7, 0.3 - 1.1 and 0.4 - 2.6 µm, respectively. This is reasonable, since visual inspection of SEM images of the particles showed relatively large fractions of smaller than specified particles in the samples. Typical silica monoliths were fabricated via phase separation by polymerization of tetramethoxysilane (TMOS) in the presence of poly(ethylene glycol) (PEG). The mean pore diameter and pore size distribution measured using the CFP system verified that a greater number of pores with small throat diameters were prepared in columns with higher PEG content in the prepolymer mixture. SEM images also showed that the pore diameters of monoliths fabricated in bulk were found to be smaller than those in monoliths synthesized by the same procedure, but confined in capillary tubes. The CFP system was also used to study the effects of column inner diameter and length on pore properties of polymeric monoliths. Typical monoliths based on butyl methacrylate (BMA) and poly(ethylene glycol) diacrylate (PEGDA) in capillary columns with different inner diameters (i.e., 50 to 250 µm) and lengths (i.e., 1.5 to 3.0 cm) were characterized. The mean pore diameters and the pore size distributions indicated that varying the inner diameter and/or the length of the column affected little the pore properties. The latter finding is especially important to substantiate the use of CFP for determination of monolithic pore structures in capillaries. The results indicate that the through-pores are highly interconnected and, therefore, pore structure determinations by CFP are independent of capillary length. A negatively charged polymer monolith based on BMA, ethylene glycol dimethacrylate (EDMA) and 2-acryloylamido-2-methylpropanesulfonic acid monomer (AMPS), was successfully prepared in silica sacrificial layer, planar (SLP) microchannels. Extraction of FITC (fluorescein 5-isothiocyanate) labeled phenylalanine and capillary electrochromatography (CEC) of FITC labeled glycine using this monolithic stationary phase were demonstrated.
4

Desenvolvimento e avaliação de métodos de extração e separação cromatográfica em colunas monolíticas e superficialmente porosas para determinação de herbicidas triazínicos em solos e águas / Development and evaluation of extraction and chromatographic methods in monolithic and core-shell columns for determination of triazine herbicides in soils and waters

Urio, Ricardo De Prá 10 December 2015 (has links)
O uso de pesticidas levou ao aumento da produtividade e qualidade dos produtos agrícolas, porém o seu uso acarreta na intoxicação dos seres vivos pela ingestão gradativa de seus resíduos que contaminam o solo, a água e os alimentos. Dessa forma, há a necessidade do monitoramento constante de suas concentrações nos compartimentos ambientais. Para isto, busca-se o desenvolvimento de métodos de extração e enriquecimento de forma rápida, com baixo custo, gerando um baixo volume de resíduos, contribuindo com a química verde. Dentre estes métodos destacam-se a extração por banho de ultrassom e a extração por ponto nuvem. Após o procedimento de extração, o extrato obtido pode ser analisado por técnicas de Cromatografia a Líquido de Alta Eficiência (HPLC) e a Cromatografia por Injeção Sequencial (SIC), empregando fases estacionárias modernas, tais como as monolíticas e as partículas superficialmente porosas. O emprego de SIC com coluna monolítica (C18, 50 x 4,6 mm) e empacotada com partículas superficialmente porosas (C18, 30 x 4,6 mm, tamanho de partícula 2,7 µm) foi estudado para separação de simazina (SIM) e atrazina (ATR), e seus metabólitos, desetilatrazina (DEA), desisopropilatrazina (DIA) e hidroxiatrazina (HAT). A separação foi obtida por eluição passo-a-passo, com fases móveis compostas de acetonitrila (ACN) e tampão Acetato de Amônio/Ácido acético (NH4Ac/HAc) 2,5 mM pH 4,2. A separação na coluna monolítica foi realizada com duas fases móveis: MP1= 15:85 (v v-1) ACN:NH4Ac/HAc e MP2= 35:65 (v v-1) ACN:NH4Ac/HAc a uma vazão de 35 µL s-1. A separação na coluna com partículas superficialmente porosas foi efetivada com as fases móveis MP1= 13:87 (v v-1) ACN: NH4Ac/HAc e MP2= 35:65 (v v-1) ACN:NH4Ac/HAc à vazão de 8 µL s-1. A extração por banho de ultrassom em solo fortificado com os herbicidas (100 e 1000 µg kg-1) resultou em recuperações entre 42 e 160%. A separação de DEA, DIA, HAT, SIM e ATR empregando HPLC foi obtida por um gradiente linear de 13 a 35% para a coluna monolítica e de 10 a 35% ACN na coluna com partículas superficialmente porosas, sendo a fase aquosa constituída por tampão NH4Ac/HAc 2,5 mM pH 4,2. Em ambas as colunas a vazão foi de 1,5 mL min-1 e o tempo de análise 15 min. A extração por banho de ultrassom das amostras de solo com presença de ATR, fortificadas com concentrações de 250 a 1000 µg kg-1, proporcionou recuperações entre 40 e 86%. A presença de ATR foi confirmada por espectrometria de massas. Foram realizados estudos de fortificação com ATR e SIM em amostras de água empregando a extração por ponto nuvem com o surfactante Triton-X114. A separação empregando HPLC foi obtida por um gradiente linear de 13 a 90% de ACN para a coluna monolítica e de 10 a 90% de ACN para a coluna empacotada, sempre em tampão NH4Ac/HAc 2,5 mM pH 4,2. Em ambas as colunas a vazão foi de 1,5 mL min-1 e o tempo de análise 16 min. Fortificações entre 1 e 50 µg L-1 resultaram em recuperações entre 65 e 132%. / The use of pesticides has led to increased productivity and quality of agricultural products, but its use brings the intoxication of living beings by the gradual intake of their residues that contaminate soil, water and food. Thus, there is the need for constant monitoring of their concentrations in environmental compartments. For this, there is a quest for development of fast extraction and enrichment methods, at low cost, generating a low volume of waste, contributing to green chemistry. These methods include the extraction assisted by ultrasound bath and the cloud point extraction. After the extraction, the extract obtained can be analyzed by techniques such as High Performance Liquid Chromatography (HPLC) and Sequential Injection Chromatography (SIC) employing modern stationary phases, such as monolithic and superficially porous particles. The use of SIC with either monolithic column (C18, 50 x 4.6 mm) or column packed with superficially porous particles (C18, 30 x 4.6 mm, 2.7 µM particle size) was studied for separating simazine (SIM) and atrazine (ATR), and metabolites, deethylatrazine (DEA), deisopropylatrazine (DIA) and hydroxyatrazine (HAT). Separation was obtained by stepwise elution, with a mobile phase consisting of acetonitrile (ACN) and 2.5 mM ammonium acetate / acetic acid (NH4Ac / HAc) pH 4.2 buffer. The separation was performed with two mobile phases: MP1 = 15:85 (v v -1) ACN: NH4Ac / HAc and MP2 = 35:65 (v v-1) ACN: NH4Ac / HAc at a flow rate of 35 µL s-1. The separation in the column with superficially porous particles was carried out with the mobile phases MP1 = 13:87 (v v-1) ACN: NH4Ac / HAc and MP2 = 35:65 (v v-1) ACN: NH4Ac / HAc at 8 µL s-1. The ultrasound bath extraction from a soil fortified with herbicides (100 and 1000 µg kg-1) resulted in recoveries between 42 and 160 %. Separation of DEA, DIA, HAT SIM and ATR was obtained by HPLC employing a linear gradient from 13 to 35% for the monolithic column and from 10 to 35% ACN in the column packed with superficially porous particles, with the aqueous phases consisting of 2.5 mM NH4Ac / HAc buffer pH 4.2. In both columns the flow rate was 1.5 mL min-1 and the analysis time was15 min. Ultrasonic extraction from a soil sample containing ATR, fortified with concentrations from 250 to 1000 µg kg-1, provided recoveries between 40 and 86%. The presence of ATR was confirmed by mass spectrometry. Fortification studies with ATR and SIM were carried out in water samples employing cloud point extraction using Triton-X114 surfactant. The separation was accomplished by HPLC using a linear gradient from 13 to 90 % of ACN for the monolithic column and from 10 to 90 % ACN for the packed column, always in 2.5 mM NH4Ac / HAc pH 4.2 buffer. In both columns the flow rate was 1.5 mL min -1 and the analysis time 16 min. Fortifications between 1 and 50 µg L-1 resulted in recoveries between 65 and 132%.
5

Desenvolvimento e avaliação de métodos de extração e separação cromatográfica em colunas monolíticas e superficialmente porosas para determinação de herbicidas triazínicos em solos e águas / Development and evaluation of extraction and chromatographic methods in monolithic and core-shell columns for determination of triazine herbicides in soils and waters

Ricardo De Prá Urio 10 December 2015 (has links)
O uso de pesticidas levou ao aumento da produtividade e qualidade dos produtos agrícolas, porém o seu uso acarreta na intoxicação dos seres vivos pela ingestão gradativa de seus resíduos que contaminam o solo, a água e os alimentos. Dessa forma, há a necessidade do monitoramento constante de suas concentrações nos compartimentos ambientais. Para isto, busca-se o desenvolvimento de métodos de extração e enriquecimento de forma rápida, com baixo custo, gerando um baixo volume de resíduos, contribuindo com a química verde. Dentre estes métodos destacam-se a extração por banho de ultrassom e a extração por ponto nuvem. Após o procedimento de extração, o extrato obtido pode ser analisado por técnicas de Cromatografia a Líquido de Alta Eficiência (HPLC) e a Cromatografia por Injeção Sequencial (SIC), empregando fases estacionárias modernas, tais como as monolíticas e as partículas superficialmente porosas. O emprego de SIC com coluna monolítica (C18, 50 x 4,6 mm) e empacotada com partículas superficialmente porosas (C18, 30 x 4,6 mm, tamanho de partícula 2,7 µm) foi estudado para separação de simazina (SIM) e atrazina (ATR), e seus metabólitos, desetilatrazina (DEA), desisopropilatrazina (DIA) e hidroxiatrazina (HAT). A separação foi obtida por eluição passo-a-passo, com fases móveis compostas de acetonitrila (ACN) e tampão Acetato de Amônio/Ácido acético (NH4Ac/HAc) 2,5 mM pH 4,2. A separação na coluna monolítica foi realizada com duas fases móveis: MP1= 15:85 (v v-1) ACN:NH4Ac/HAc e MP2= 35:65 (v v-1) ACN:NH4Ac/HAc a uma vazão de 35 µL s-1. A separação na coluna com partículas superficialmente porosas foi efetivada com as fases móveis MP1= 13:87 (v v-1) ACN: NH4Ac/HAc e MP2= 35:65 (v v-1) ACN:NH4Ac/HAc à vazão de 8 µL s-1. A extração por banho de ultrassom em solo fortificado com os herbicidas (100 e 1000 µg kg-1) resultou em recuperações entre 42 e 160%. A separação de DEA, DIA, HAT, SIM e ATR empregando HPLC foi obtida por um gradiente linear de 13 a 35% para a coluna monolítica e de 10 a 35% ACN na coluna com partículas superficialmente porosas, sendo a fase aquosa constituída por tampão NH4Ac/HAc 2,5 mM pH 4,2. Em ambas as colunas a vazão foi de 1,5 mL min-1 e o tempo de análise 15 min. A extração por banho de ultrassom das amostras de solo com presença de ATR, fortificadas com concentrações de 250 a 1000 µg kg-1, proporcionou recuperações entre 40 e 86%. A presença de ATR foi confirmada por espectrometria de massas. Foram realizados estudos de fortificação com ATR e SIM em amostras de água empregando a extração por ponto nuvem com o surfactante Triton-X114. A separação empregando HPLC foi obtida por um gradiente linear de 13 a 90% de ACN para a coluna monolítica e de 10 a 90% de ACN para a coluna empacotada, sempre em tampão NH4Ac/HAc 2,5 mM pH 4,2. Em ambas as colunas a vazão foi de 1,5 mL min-1 e o tempo de análise 16 min. Fortificações entre 1 e 50 µg L-1 resultaram em recuperações entre 65 e 132%. / The use of pesticides has led to increased productivity and quality of agricultural products, but its use brings the intoxication of living beings by the gradual intake of their residues that contaminate soil, water and food. Thus, there is the need for constant monitoring of their concentrations in environmental compartments. For this, there is a quest for development of fast extraction and enrichment methods, at low cost, generating a low volume of waste, contributing to green chemistry. These methods include the extraction assisted by ultrasound bath and the cloud point extraction. After the extraction, the extract obtained can be analyzed by techniques such as High Performance Liquid Chromatography (HPLC) and Sequential Injection Chromatography (SIC) employing modern stationary phases, such as monolithic and superficially porous particles. The use of SIC with either monolithic column (C18, 50 x 4.6 mm) or column packed with superficially porous particles (C18, 30 x 4.6 mm, 2.7 µM particle size) was studied for separating simazine (SIM) and atrazine (ATR), and metabolites, deethylatrazine (DEA), deisopropylatrazine (DIA) and hydroxyatrazine (HAT). Separation was obtained by stepwise elution, with a mobile phase consisting of acetonitrile (ACN) and 2.5 mM ammonium acetate / acetic acid (NH4Ac / HAc) pH 4.2 buffer. The separation was performed with two mobile phases: MP1 = 15:85 (v v -1) ACN: NH4Ac / HAc and MP2 = 35:65 (v v-1) ACN: NH4Ac / HAc at a flow rate of 35 µL s-1. The separation in the column with superficially porous particles was carried out with the mobile phases MP1 = 13:87 (v v-1) ACN: NH4Ac / HAc and MP2 = 35:65 (v v-1) ACN: NH4Ac / HAc at 8 µL s-1. The ultrasound bath extraction from a soil fortified with herbicides (100 and 1000 µg kg-1) resulted in recoveries between 42 and 160 %. Separation of DEA, DIA, HAT SIM and ATR was obtained by HPLC employing a linear gradient from 13 to 35% for the monolithic column and from 10 to 35% ACN in the column packed with superficially porous particles, with the aqueous phases consisting of 2.5 mM NH4Ac / HAc buffer pH 4.2. In both columns the flow rate was 1.5 mL min-1 and the analysis time was15 min. Ultrasonic extraction from a soil sample containing ATR, fortified with concentrations from 250 to 1000 µg kg-1, provided recoveries between 40 and 86%. The presence of ATR was confirmed by mass spectrometry. Fortification studies with ATR and SIM were carried out in water samples employing cloud point extraction using Triton-X114 surfactant. The separation was accomplished by HPLC using a linear gradient from 13 to 90 % of ACN for the monolithic column and from 10 to 90 % ACN for the packed column, always in 2.5 mM NH4Ac / HAc pH 4.2 buffer. In both columns the flow rate was 1.5 mL min -1 and the analysis time 16 min. Fortifications between 1 and 50 µg L-1 resulted in recoveries between 65 and 132%.
6

Nosná konstrukce víceúčelové budovy / Load-bearing Structure of Multi-purpose Building

Hetmer, Jakub January 2015 (has links)
This master´s thesis“ Load-bearing Structure of Multi-purpose Building“ is processed in the form of project documentation according to applicable regulations. It deals with static solution of monolitic reinforced concrete construction of administrative building of Česká spořitelna. Subject of the solutions is reinforced concrete monolithic point – supported ceiling slab, columns and staircase.
7

Cromatografia a líquido por injeção sequencial para a determinação de herbicidas triazínicos e metabólitos da atrazina explorando o uso de cela de longo caminho óptico e monitoramento on-line em estudos de adsorção / Sequential injection liquid chromatography for the determination of triazine herbicides and metabolites of atrazine exploring the use of long optical pathlength flow cell and on line monitoring of adsorption studies

Urio, Ricardo de Prá 16 May 2011 (has links)
Estudou-se o emprego da Cromatografia a Líquido por Injeção Seqüencial (SIC) explorando o uso de uma cela de longo caminho óptico com guia de onda (LCW) de 100 cm para a melhora dos limites de detecção (LOD) e quantificação (LOQ) na determinação de atrazina (ATR), propazina (PRO) e simazina (SIM). Para isto, utilizou-se uma fase móvel com composição de 44:56 (v v-1) metanol : tampão acetato de amônio 1,25 mM, pH 4,7, coluna monolítica e a detecção espectrofotométrica em 238 nm. Obtiveram-se valores de LOD e LOQ, respectivamente, de 1,76 e 5,86 &#181;g L-1 para ATR, 4,51 e 15 &#181;g L-1 para PRO e 2,25 e 7,5 &#181;g L-1 para SIM. Com o emprego da cela de longo caminho óptico os valores de LOD ficaram abaixo dos recomendados pela US-EPA, que permite para águas potáveis uma concentração de 3 &#181;g L-1 para ATR, 4 &#181;g L-1 para SIM e 10 &#181;g L-1 para PRO. Realizaram-se estudos de adsorção de SIM, PRO e ATR e seus metabólitos desisopropilatrazina (DIA), desetilatrazina (DEA) e 2-hidroxiatrazina (HAT) em solo, ácido húmico e solo modificado com ácido húmico. Para isso foi utilizado um sistema de monitoramento on-line composto por um filtro tangencial e uma bomba peristáltica para circulação da suspensão. Foram realizados estudos cinéticos em duas etapas e, em ambas, foi utilizado um mix dos compostos com concentração inicial de 1,0 mg L-1 e gradiente de eluição passo a passo para a separação dos compostos utilizando três fases móveis com composições de 15 ou 28, 40 e 50% (v v-1) metanol : tampão acetato de amônio 1,25 mM pH 4,7. Na primeira etapa o tempo de contato entre triazinas e adsorventes foi de 90 min. Na segunda etapa foi utilizado apenas o solo como adsorvente e o tempo de contato foi de 24 h. Para a primeira etapa do estudo só foi possível aplicar modelo cinético de pseudo-segunda ordem, o qual permitiu estimar os valores de massa adsorvida de triazina por massa de adsorvente, sendo que o ácido húmico é o material com maior capacidade adsortiva (1470 ± 43&#181;g g-1 para DIA a 2380 ± 51 &#181;g g-1 para PRO). O composto mais adsorvido em solo é PRO (26,5 ± 0,1 &#181;g g-1). A presença de ácido húmico no solo aumentou a adsorção de ATR (de 19,4 ± 0,7 para 23 ± 2 &#181;g g-1), de HAT (10,9 ± 0,7 para 18 ± 2 &#181;g g-1) e de PRO (26,5 ± 0,7 para 29,8 ±0,2 &#181;g g-1), mas diminuiu a adsorção de SIM e não afetou DIA e DEA. No estudo com tempo de contato de 24 h foi possível aplicar modelos de pseudo-primeira e segunda ordem. Os resultados obtidos confirmaram a maior adsorção de PRO, seguidos da ATR. HAT, SIM, DEA e DIA apresentaram as menores taxas de adsorção em solo, sendo que os dois últimos apresentaram uma tendência de dessorção após 4 h de contato, tendo maior potencial de lixiviação para corpos d\'água próximos aos locais de aplicação. / This work describes the use of Sequential Injection Liquid Chromatography (SIC) coupled to a long path length optical flow cell with 100 cm long Liquid Core Waveguide (LCW) to improve the limits of detection (LOD) and quantification (LOQ) for determination of atrazine (ATR), propazine (PRO) and simazine (SIM). Separation was achieved with a mobile phase composition of 44:56 (v v-1) methanol:1.25 mM ammonium acetate buffer, pH 4.7, monolithic column and spectrophotometric detection at 238 nm. The values of LOD and LOQ were, respectively, 1.76 and 5.86 &#181;g L-1 for ATR, 4.51 and 15 &#181;g L-1 for PRO and 2.25 and 7.5 &#181;g L-1 for SIM. The LOD values achieved with the employment of long optical path cell were lower than those recommended by US-EPA, which allows for drinking water, maximum concentration levels of 3 &#181;g L-1 for ATR, 4 &#181;g L-1 for SIM and 10 &#181;g L-1 for PRO. Adsorption of SIM, PRO and ATR, as well as their metabolites desisopropylatrazine (DIA), desethylatrazine (DEA) and 2-hidroxyatrazine (HAT) on soil, humic acid and soil modified with humic acidic was studied. An on-line monitoring system was assembled, composed of a tangential filter and a peristaltic pump for circulation of the suspension. Kinetic studies were carried out in two steps, and in both, it was used a mix of compounds with initial concentration of 1,0 mg L-1 and a stepwise gradient elution for separation of the compounds using three mobile phases with compositions of 15 or 28, 40 and 50% (v v-1) methanol: 1.25 mM ammonium acetate buffer, pH 4.7. In the first step the contact time between triazines and adsorbents was 90 minutes. In a second study made only with soil, the contact time was 24 h. Data obtained in the first stage of the study was only fitted to pseudo-second order kinetic equation, which allowed one to estimate the values of the adsorbed mass of triazine per mass of adsorbent. Humic acid was the material with higher adsorptive capacity (from 1470 ± 43 &#181;g g-1 for DIA to 2380 ± 50 &#181;g g-1 for PRO). In soil, PRO exhibited the highest adsorption (26.5 ± 0.1 &#181;g g-1). The presence of humic acid in the soil increased adsorption of ATR (19.4±0.7 to 23±2 &#181;g g-1), HAT (10.9 ± 0.7 to 18 ± 2 &#181;g g-1) and PRO (26.5 ± 0.7 to 29.8 ± 0.2 &#181;g g-1), but decreased adsorption of SIM, not affecting DIA and DEA. In the study with contact time of 24 h, it was possible apply pseudo-first and pseudo-second order equations for SIM, ATR and PRO. The results confirmed the greatest adsorption of PRO, followed by ATR. HAT, SIM, DEA and DIA had low rates of adsorption on soil, the latter two showed a trend of desorption after 4 h of contact, having the greatest potential for leaching to water bodies near to the places of application.
8

Cromatografia a líquido por injeção sequencial para a determinação de herbicidas triazínicos e metabólitos da atrazina explorando o uso de cela de longo caminho óptico e monitoramento on-line em estudos de adsorção / Sequential injection liquid chromatography for the determination of triazine herbicides and metabolites of atrazine exploring the use of long optical pathlength flow cell and on line monitoring of adsorption studies

Ricardo de Prá Urio 16 May 2011 (has links)
Estudou-se o emprego da Cromatografia a Líquido por Injeção Seqüencial (SIC) explorando o uso de uma cela de longo caminho óptico com guia de onda (LCW) de 100 cm para a melhora dos limites de detecção (LOD) e quantificação (LOQ) na determinação de atrazina (ATR), propazina (PRO) e simazina (SIM). Para isto, utilizou-se uma fase móvel com composição de 44:56 (v v-1) metanol : tampão acetato de amônio 1,25 mM, pH 4,7, coluna monolítica e a detecção espectrofotométrica em 238 nm. Obtiveram-se valores de LOD e LOQ, respectivamente, de 1,76 e 5,86 &#181;g L-1 para ATR, 4,51 e 15 &#181;g L-1 para PRO e 2,25 e 7,5 &#181;g L-1 para SIM. Com o emprego da cela de longo caminho óptico os valores de LOD ficaram abaixo dos recomendados pela US-EPA, que permite para águas potáveis uma concentração de 3 &#181;g L-1 para ATR, 4 &#181;g L-1 para SIM e 10 &#181;g L-1 para PRO. Realizaram-se estudos de adsorção de SIM, PRO e ATR e seus metabólitos desisopropilatrazina (DIA), desetilatrazina (DEA) e 2-hidroxiatrazina (HAT) em solo, ácido húmico e solo modificado com ácido húmico. Para isso foi utilizado um sistema de monitoramento on-line composto por um filtro tangencial e uma bomba peristáltica para circulação da suspensão. Foram realizados estudos cinéticos em duas etapas e, em ambas, foi utilizado um mix dos compostos com concentração inicial de 1,0 mg L-1 e gradiente de eluição passo a passo para a separação dos compostos utilizando três fases móveis com composições de 15 ou 28, 40 e 50% (v v-1) metanol : tampão acetato de amônio 1,25 mM pH 4,7. Na primeira etapa o tempo de contato entre triazinas e adsorventes foi de 90 min. Na segunda etapa foi utilizado apenas o solo como adsorvente e o tempo de contato foi de 24 h. Para a primeira etapa do estudo só foi possível aplicar modelo cinético de pseudo-segunda ordem, o qual permitiu estimar os valores de massa adsorvida de triazina por massa de adsorvente, sendo que o ácido húmico é o material com maior capacidade adsortiva (1470 ± 43&#181;g g-1 para DIA a 2380 ± 51 &#181;g g-1 para PRO). O composto mais adsorvido em solo é PRO (26,5 ± 0,1 &#181;g g-1). A presença de ácido húmico no solo aumentou a adsorção de ATR (de 19,4 ± 0,7 para 23 ± 2 &#181;g g-1), de HAT (10,9 ± 0,7 para 18 ± 2 &#181;g g-1) e de PRO (26,5 ± 0,7 para 29,8 ±0,2 &#181;g g-1), mas diminuiu a adsorção de SIM e não afetou DIA e DEA. No estudo com tempo de contato de 24 h foi possível aplicar modelos de pseudo-primeira e segunda ordem. Os resultados obtidos confirmaram a maior adsorção de PRO, seguidos da ATR. HAT, SIM, DEA e DIA apresentaram as menores taxas de adsorção em solo, sendo que os dois últimos apresentaram uma tendência de dessorção após 4 h de contato, tendo maior potencial de lixiviação para corpos d\'água próximos aos locais de aplicação. / This work describes the use of Sequential Injection Liquid Chromatography (SIC) coupled to a long path length optical flow cell with 100 cm long Liquid Core Waveguide (LCW) to improve the limits of detection (LOD) and quantification (LOQ) for determination of atrazine (ATR), propazine (PRO) and simazine (SIM). Separation was achieved with a mobile phase composition of 44:56 (v v-1) methanol:1.25 mM ammonium acetate buffer, pH 4.7, monolithic column and spectrophotometric detection at 238 nm. The values of LOD and LOQ were, respectively, 1.76 and 5.86 &#181;g L-1 for ATR, 4.51 and 15 &#181;g L-1 for PRO and 2.25 and 7.5 &#181;g L-1 for SIM. The LOD values achieved with the employment of long optical path cell were lower than those recommended by US-EPA, which allows for drinking water, maximum concentration levels of 3 &#181;g L-1 for ATR, 4 &#181;g L-1 for SIM and 10 &#181;g L-1 for PRO. Adsorption of SIM, PRO and ATR, as well as their metabolites desisopropylatrazine (DIA), desethylatrazine (DEA) and 2-hidroxyatrazine (HAT) on soil, humic acid and soil modified with humic acidic was studied. An on-line monitoring system was assembled, composed of a tangential filter and a peristaltic pump for circulation of the suspension. Kinetic studies were carried out in two steps, and in both, it was used a mix of compounds with initial concentration of 1,0 mg L-1 and a stepwise gradient elution for separation of the compounds using three mobile phases with compositions of 15 or 28, 40 and 50% (v v-1) methanol: 1.25 mM ammonium acetate buffer, pH 4.7. In the first step the contact time between triazines and adsorbents was 90 minutes. In a second study made only with soil, the contact time was 24 h. Data obtained in the first stage of the study was only fitted to pseudo-second order kinetic equation, which allowed one to estimate the values of the adsorbed mass of triazine per mass of adsorbent. Humic acid was the material with higher adsorptive capacity (from 1470 ± 43 &#181;g g-1 for DIA to 2380 ± 50 &#181;g g-1 for PRO). In soil, PRO exhibited the highest adsorption (26.5 ± 0.1 &#181;g g-1). The presence of humic acid in the soil increased adsorption of ATR (19.4±0.7 to 23±2 &#181;g g-1), HAT (10.9 ± 0.7 to 18 ± 2 &#181;g g-1) and PRO (26.5 ± 0.7 to 29.8 ± 0.2 &#181;g g-1), but decreased adsorption of SIM, not affecting DIA and DEA. In the study with contact time of 24 h, it was possible apply pseudo-first and pseudo-second order equations for SIM, ATR and PRO. The results confirmed the greatest adsorption of PRO, followed by ATR. HAT, SIM, DEA and DIA had low rates of adsorption on soil, the latter two showed a trend of desorption after 4 h of contact, having the greatest potential for leaching to water bodies near to the places of application.
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Nosná ŽB konstrukce objektu hotelu / Load bearing RC structure of hotel building

Macourková, Klára January 2014 (has links)
The thesis deals with the static solution of monolitic reinforced concrete concstruction of hotel building. Subject of the solutions is reinforced concrete monolithic point – supported ceiling slab, columns, foundations and staircase. Assesment of these structures by the first ultimate state – carrying capacity.

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