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Magnetic adsorption separation process for industrial wastewater treatment using polypyrrole-magnetite nanocomposite.Muthui, Muliwa Anthony. January 2013 (has links)
M.Tech. Engineering: Chemical. / Aims at demonstrating the application of semi-continuous and continuous magnetic adsorption separation (MAS) techniques to extract Cr (VI) ions from wastewater streams using PPy-Fe3O4 nanocomposite. Specifically, the research aims to achieve the following objectives: to design, synthesize and characterize new generation PPy-Fe3O4 nanocomposite with varied magnetite composition for hexavalent chromium removal ; to generate batch adsorption kinetic data in a continuously stirred tank reactor (CSTR) and apply existing kinetic models to aid in water treatment system design.; to design and construct magnetic adsorption separation (MAS) device that can operate in a semi-continuous and continuous mode and explore their performances and to optimize the systems' performance.
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Extração e caracterização da composição lipídica da borra de café e o estudo do potencial aproveitamento deste resíduo / Extraction and characterization of lipid composition coffee borra and the study of potential utilization of this wasteMoura, Cleber Luiz de 30 September 2016 (has links)
A borra de café, gerada em grande quantidade na produção de café solúvel, tornou- se um problema por se tratar de um resíduo industrial, porém por apresentar um alto teor de lipídios, em torno de 20%, uma alternativa comercial viável é a extração e a utilização desse óleo Este trabalho teve por objetivo extrair e caracterizar a fração lipídica da borra de Café Robusta e Arábica por dois processos: por Soxtec utilizando como solvente éter de petróleo, e por meio pressurizado usando etanol. Os rendimentos da extração por meio convencional soxhlet (soxtec, extrator da marca FOSS), foram em média 19,18% e 22,16% para as qualidades Robusta e Arábica, respectivamente. Por meio pressurizado o rendimento obtido foi 18,1% para a qualidade Robusta. Realizou-se a transesterificação dos óleos da borra de café para posterior caracterização do perfil lipídico do óleo da borra, utilizando cromatografia gasosa com espectrometria de massas (GC-MS). A transesterificação via catálise ácida mostrou-se mais eficiente na conversão dos triagliceróis em ésteres, já que na catálise básica favorece a reação de saponificação devido elevado teor ácidos graxos livres. Foram identificados como componentes majoritários o Palmitato de metila em torno de 30% e o Linoleato de Metila em torno de 40% nas duas espécies de café avaliadas. / The coffee grounds generated in large quantities in the production of instant coffee, has become a problem because it is an industrial waste. For the present a lipid content of about 20%, is the extraction of this oil for varied purposes. This study aimed to extract and characterize the lipid fraction of Robusta coffee grounds and Arabica for two extraction processes: extraction Soxtec as solvent petroleum ether, and pressurized by using ethanol as a solvent. It carried out the transesterification of oils from the coffee grounds through acidic and basic, for further characterization of the lipid profile of the oil sludge using gas chromatography-mass spectrometry (GC- MS). The hot extraction yields were on average 19.18% and 22.16% for Robusta and Arabica quality, respectively, whereas the yield obtained by the pressure was 18.1% Robusta quality. The transesterification via acid catalysis was more efficient in conversion of triagliceróis esters, as in base catalysis favors a saponification reaction because high free fatty acids content. The majority were identified as methyl palmitate around 30% Methyl linoleate and around 40% in about two species.
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Otimização multivariada de extração de compostos bioativos em folhas, casca e resíduos de seiva de Croton lechleri / Multivariate optimization of bioactive compounds extraction in Croton lechleri leaves, bark and sap residueDiedrich, Camila 28 February 2018 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / As plantas naturais da Amazônia vêm instigando o interesse de pesquisadores a extrair os produtos desta região. O intuito destas pesquisas foca no desenvolvimento de novos fármacos a partir dos compostos bioativos de plantas visando o combate de inúmeras doenças associadas ao aumento na produção de espécies reativas de oxigênio. A seiva, folhas e cascas de plantas do gênero Croton são utilizadas pelos povos nativos amazônicos para fins medicinais com ação cicatrizante, anti-inflamatória e antibacteriana. Este estudo teve como objetivo otimizar o processo de extração de produtos naturais de folhas, cascas de extratos de C. lechleri. O delineamento para extração de compostos naturais foi realizado por meio de planejamento fatorial 2³ e análise por metodologia de superfície de resposta (RSM). Três fatores (variáveis independentes); tipo de solvente (água ou etanol), tempo de extração (30 ou 90 min) e temperatura de extração (35°C e 70°C) foram utilizados para o delineamento experimental. Enquanto que as variáveis dependentes; teor de compostos fenólicos, atividade antioxidante por DPPH, e teor de antocianinas foram avaliadas nos extratos de C. lechleri. A composição da diversidade de compostos fenólicos foi investigada por cromatografia líquida de alta eficiência. O conjunto de dados foi submetido à análise de componentes principais (ACP). A melhor condição de extração de compostos fenólicos foi água, a 70 ºC por 30 min, enquanto que para os compostos com atividade antioxidante foi etanol, a 70 ºC por 90 min. A análise por cromatografia revelou a presença majoritariamente de ácido gálico, catequina, epicatequina, ácido siríngico, ácido cumárico e ácido ferrúlico. Por fim, o delineamento fatorial permitiu a redução do número de ensaios realizados sem diminuir a qualidade da informação e dos resultados da análise de variância. Metodologia de superfície de resposta e análise de componentes principais empregadas provaram ser ferramentas eficientes para analisar dados da bioatividade de extratos de C. lechleri. / The natural plants of the Amazon have been instigating the interest of researchers to extract the products of the region. The purpose of this research focuses on no development of new drugs from bioactive plant compounds aimed at fighting numerous diseases associated with increased production of reactive oxygen species. The sap, leaves and barks of plants of the genus Croton are used by native Amazonian peoples for medicinal purposes with healing, anti-inflammatory and antibacterial action. This study aimed to optimize the extraction process of natural products from leaves, bark of C. lechleri extracts. The design for the extraction of natural compounds was performed by 2³ factorial experimental design and analysis using Response Surface Methodology (RSM). Three factors (independent variables); type of solvent (water or ethanol), extraction time (30 or 90 min) and extraction temperature (35 °C and 70 °C) were used for the experimental design. While the dependent variables; content of phenolic compounds, antioxidant activity by DPPH, and anthocyanin content were evaluated in extracts of C. lechleri. The composition of the diversity of phenolic compounds was investigated by high performance liquid chromatography. The data set was submitted to Principal Component Analysis (PCA). The best extraction condition of phenolic compounds was water, at 70 ºC for 30 min, while for the compounds with antioxidant activity was ethanol, at 70 ºC for 90 min. Chromatographic analysis revealed the presence of gallic acid, catechin, epicatechin, syringic acid, coumaric acid and ferulic acid. Finally, the factorial design allowed the reduction of the number of tests carried out without diminishing the quality of information and the results of analysis of variance. Response Surface Methodology and Principal Component Analysis proved to be efficient tools used to analyze data bioactivity of extracts from C. lechleri.
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Bioatividade da Quassia amara L. e estabilidade oxidativa sobre o óleo de soja / Bioavailability of Quassia amara L. and oxidative stability on soybean oilReis, Amália Soares dos 21 February 2017 (has links)
CAPES / A procura cada vez maior por produtos naturais pelos consumidores, leva a uma busca intensificada por antioxidantes naturais, visando a substituição dos antioxidantes sintéticos utilizados pela indústria de alimentos. Essa substituição faz-se necessária devido aos efeitos danosos que essas substâncias causam a saúde. A Quassia amara é uma planta nativa do norte do Brasil, pertencente a família Simaroubaceae e utilizada para combater a malária e problemas gastrointestinais. Este trabalho teve como objetivo otimizar o método de extração de compostos com atividade antioxidante presentes nas folhas de Quassia amara por meio de um delineamento fatorial, avaliar a atividade antioxidante e antibacteriana, identificar e isolar suas substâncias ativas. Foi também objetivo aplicar o extrato em óleo de soja e avaliar os efeitos na inibição oxidativa e nas caracteristicas sensoriais. A melhor condição encontrada para extração de compostos com atividade antioxidante das folhas de Quassia amara foi com o solvente metanol, a 70 °C durante 60 minutos. A análise cromatográfica revelou a presença de ácido gálico (58,12 μg.g-1) e catequina (42,4 μg.g-1). Por meio da análise espectroscópica de RMN de 1H e 13C, foi possível a identificação do alcano octadecano, o qual foi isolado pela primeira vez nas folhas de Quassia amara. O extrato metanólico revelou elevada atividade antioxidante pelo método do sequestro do radical DPPH (1898,02 μmol Trolox.g-1), e apresentou ação inibitória frente aos microrganismos Staphylococcus aureus e Salmonella bongori, com concentração inibitória mínima (CIM) de 0,625 mg.mL-1 e 0,312 mg.mL-1, respectivamente. Por fim, o extrato metanólico de Quassia amara conseguiu retardar a oxidação do óleo de soja. Tal capacidade pôde ser confirmada tanto pelas análises químicas como também pela análise sensorial com painel de julgadores treinados quanto o sabor ranço. Em vista disso, a planta possui potencial para a substituição aos antioxidantes sintéticos amplamente utilizados na indústria alimentícia. / The increasing demand for natural products by consumers leads to an intensified search for natural antioxidants, aimed at replacing the synthetic antioxidants used by the food industry. Such substitution is necessary because of the harmful effects these substances cause to health. Quassia amara is a plant native to northern Brazil, belonging to the family Simaroubaceae and used to combat malaria and gastrointestinal problems. The objective of this work was to optimize the extraction of compounds with antioxidant activity in the leaves of Quassia amara by means of a factorial design, to evaluate antioxidant and antibacterial activity, to identify and isolate their active substances. It was also the objective to apply the extract in soybean oil and evaluate the effects on oxidative inhibition and sensorial characteristics. The optimal condition found for extracting compounds with antioxidant activity from Quassia amara leaves was with solvent methanol at 70 °C for 60 minutes of extraction. Chromatographic analysis revealed the presence of gallic acid (58.12 μg.g-1) and catechin (42.4 μg.g-1). By means of 1H and 13C NMR spectroscopic analysis, it was possible to identify the alkane octadecane, which was isolated for the first time in the leaves of Quassia amara. The methanolic extract of Quassia amara showed high antioxidant activity by the sequestration method of the DPPH radical (1898.02 μmol Trolox.g-1), and presented an inhibitory action against Staphylococcus aureus and Salmonella bongori microorganisms, with minimum inhibitory concentration (MIC) of 0.625 mg.mL-1 and 0.312 mg.mL-1, respectively. Finally, the methanolic extract of Quassia amara was able to retard the oxidation of soybean oil. Such ability could be confirmed by both chemical analyzes and by the sensory analysis with panel of judges trained as to the rancid flavor. In view of this, the plant has potential for substitution to synthetic antioxidants widely used in the food industry.
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Desacidificação do OFA atraves do processo de extração liquido-liquido descontinuo utilizando alcoois / Rice poil Brain desacidification in a descontinuous liquid-liquid extraction process using alcoholsOrlandelli, Maria Claudia Faes da Silva 25 July 2008 (has links)
Orientador: Elias Basile Tambourgi / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-11T17:05:57Z (GMT). No. of bitstreams: 1
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Previous issue date: 2008 / Resumo: Os óleos vegetais estão presentes na gastronomia de diferentes culturas tornando os pratos típicos ainda mais atraentes para os nossos sentidos: olfato, visão e paladar, além de constituírem importante fonte de energia, ácidos graxos essenciais, vitaminas e antioxidantes lipossolúveis. O óleo de farelo de arroz (OFA) destaca-se entre outros óleos vegetais, sendo equiparável aos óleos de soja, milho e algodão. O OFA apresenta em sua composição um alto nível de substâncias nutracêuticas, as quais tem poderosos agentes antioxidantes eficientes na prevenção de doenças. Dentre os diversos meios conhecidos para extração de óleos vegetais, os processos mais utilizados são os físico e químico, que apresentam desvantagens em relação ao processo líquido-líquido. A desacidificação de óleos vegetais por extração líquido-líquido tem-se mostrado como um caminho alternativo na obtenção de óleos vegetais com teores aceitáveis de ácidos graxos livres. A razão para a utilização deste novo processo em relação aos processos citados, está no fato de consumir menor quantidade de energia, pois é realizado a temperatura ambiente e pressão atmosférica além de não gerar sabão e minimizar a perda do óleo neutro. Neste contexto, o presente trabalho tem como objetivo selecionar o solvente mais eficiente na desacidificação do OFA durante o processo de extração líquido-líquido descontínuo. Tendo se em vista o estudo feito para determinação do coeficiente de partição K nos sistemas bifásicos aquosos OFA/Solvente, após análise dos resultados parece-nos lógico concluir que: o sistema OFA/Etanol, nas condições testadas foi o que apresentou a melhor separação dos ácidos graxos, tendo o menor valor de K igual a 0,07. Os resultados obtidos no presente trabalho permitiram concluir que, a partir da comparação feita entre Metanol, Etanol, Isopropanol e Propanol, o Etanol apresenta os menores valores de K portanto, melhor separação dos ácido graxos / Abstract: The vegetable oil is present in the gastronomy of different cultures,making the food even more attractive to our senses: smell,sight and taste.Besides being an important source of energy it also contains vitamins, nutraceutical compounds and antioxidant liposoluble. Rice brain oil is one of the best vegetable oil, it possesses powerful antioxidant compound thus is is very effective in preventing disease. The deacidification oil process throught liquid-liquid extraction has revealed a new way to extract the vegetable oil with an acceptable level of free fatty acid and it has advantages over the physical and chemical ones. The reason for the use of this new process in regardining to those ones, it is for the fact of optimising the waste of energy because it can be undertaken at room temperature and with atmospheric pressure (at non-especial grounds), besides this, also the liquid-liquid extraction avoid the formation of soap normally resultant from the other process, and it can minimize the loss of neutral oil. This piece of work aims to point out the importance of select the most effective solvent in the deacidification of the rice bran oil during the liquid-liquid discontinuos extraction process. This study has been done to determine the coefficient of patition K, in biphasic watery systems RBO/solvent above mentioned. The experience showed that the Ethanol pesented the best results among all solvents used to separate the free fatty acid, with K 0,07 / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestre em Engenharia Química
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Steam extraction of essential oils : investigation of process parametersKabuba, John Tshilenge 12 September 2012 (has links)
M.Tech. / Essential oils are volatile oils, generally odorous, which occur in certain plants or specified parts of plants, and are recovered by accepted procedures, such that the nature and composition of the product is, as nearly as practicable, unchanged by such procedures (ISO, 1968). The principal uses are as: flavouring agent, medicinal and aromatherapy application. Today, the essential oils are sought-after for innumerable applications starting from markers for plant identifications to bases for semi-synthesis of highly complex molecules. The extraction of highly delicate essential oils from plants remains a crucial step in all these applications. By using steam to mediate the extraction, it is possible to maintain mild conditions and effect superior extraction. In the current work, an integrated procedure for steam extraction followed by volatiles sampling and analysis from the leaves of the Eucalyptus tree was explored. There are two problems to overcome in the extraction from solid plant materials: that of releasing the essential oils from solid matrix and letting it diffuse out successfully in a manner that can be scaled-up to industrial volumes. Towards this end, the effect of different parameters, such as temperature, pressure and extraction time on the extraction yield was investigated and the experimental results show that all of these temperatures (90 °C, 97°C, and 99°C), were significant parameters affecting yield. Increase in yield was observed as pressure was increased and the use of high pressure (150 kPa) in steam extraction units permits much more rapid and complete distillation of essential oils over atmospheric pressure. The yield was calculated from the relation between the essential oil mass extracted and the raw material mass used in the extraction. The volatiles, Eucalyptus oil in vapour form released from the leaves were condensed and analyzed using Gas chromatography, and eight major components were found to be contained in this species. A mathematical model based on diffusion of essential oil from the leaves was developed. Using a numerical method, the best diffusion coefficient was established for different operating conditions by comparing the model concentration of oil remaining in the leaves with the experimental amount of oil recovered; hence minimizing the sum of squared errors. It was found that one cannot simply assume that the oil leached and recovered was the same as that originally present in the leaves. The initial mass of oil was determined by fitting the diffusion model to the data. An Arrhenius model was used to account for the effect of temperature. The resulting expression for the diffusion coefficient as a function of temperature can now be used to model the large scale extraction of the essential oils from Eucalyptus leaves.
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Facile Methods for the Analysis of Lysophosphatidic Acids in Human PlasmaWang, Jialu 16 March 2015 (has links)
Lysophosphatidic acid (LPA) influences many physiological processes, such as brain and vascular development. It is associated with several diseases including ovarian cancer, breast cancer, prostate cancer, colorectal cancer, hepatocellular carcinoma, multiple myeloma atherosclerotic diseases, cardiovascular diseases, pulmonary inflammatory diseases and renal diseases. LPA plasma and serum levels have been reported to be important values in diagnosing ovarian cancer and other diseases. However, the extraction and quantification of LPA in plasma are very challenging because of the low physiological concentration and similar structures of LPA to other phospholipids. Many previous studies have not described the separation of LPA from other phospholipids, which may make analyses more challenging than necessary.
We developed an SPE extraction method for plasma LPA that can extract LPA at high purity. We also developed an HPLC post-column fluorescence detection method that allows the efficient quantification of LPA. These methods were used in a clinical study for ovarian cancer diagnosis to help validate LPA as a biomarker of ovarian cancer. Moreover, molecular imprinted polymers (MIPs) were designed and synthesized as material for the improved extraction of LPA. Compared to the commercially available materials, the MIP developed shows enhanced selectivity for LPA. The extraction was overall relatively more efficient and less labor-intensive.
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Identification of Tobacco-Related Compounds in Tobacco Products and Human HairRainey, Christina 04 September 2014 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Analyses of tobacco products and their usage are well-researched and have implications in analytical chemistry, forensic science, toxicology, and medicine. As such, analytical methods must be developed to extract compounds of interest from tobacco products and biological specimens in order to determine tobacco exposure.
In 2009, R.J. Reynolds Tobacco Co. released a line of dissolvable tobacco products that are marketed as a smoking alternative. The dissolvables were extracted and prepared by ultrasonic extractions, derivatization, and headspace solid phase microextraction (SPME) with analysis by gas chromatography-mass spectrometry (GC-MS). The results show that the compounds present are nicotine, flavoring compounds, humectants and binders. Humectant concentrations vary among different tobacco types depending on the intended use. Humectants were quantified in various tobacco types by GC and “splitting” the column flow between a flame ionization detector (FID) and an MS using a microfluidic splitter in order to gain advantage from the MS’s selectivity. The results demonstrated excellent correlation between FID and MS
and show that MS provides a higher level of selectivity and ensures peak purity. Chemometrics was also used to distinguish products by tobacco type.
Hair is a common type of evidence in forensic investigations, and it is often subjected to mitochondrial DNA (mtDNA) analysis. Preliminary data was gathered on potential “lifestyle” markers for smoking status as well as any indications of subject age, gender, or race by investigating the organic “waste” produced during a mtDNA extraction procedure. The normally discarded organic fractions were analyzed by GC-MS and various lipids and fatty acids were detected.
At this point, a total vaporization-SPME (TV-SPME) method was theorized, developed, and optimized for the specific determination of nicotine and its metabolite, cotinine. The theory of TV-SPME is to completely vaporize an organic extract which will eliminate the partitioning between the sample and the headspace, thereby simplifying the thermodynamic equilibrium. Parameters such as sample volume, incubation temperature, and extraction time were optimized to achieve the maximum analyte signal. Response surface methodology (RSM) is a statistical model that is very useful in predicting and determining optimum values for variables to ensure the ideal response. RSM was used to optimize the technique of TV-SPME for the analysis of nicotine and cotinine.
Lastly, quantitation of nicotine and cotinine in human hair typically requires large sample sizes and extensive extraction procedures. Hence, a method using small sample sizes and a simple alkaline digestion followed by TV-SPME-GC-MS has been developed. Hair samples were collected from anonymous volunteers and nicotine and cotinine were identified and quantitated in the hair of tobacco users.
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Modeling in-situ vapor extraction during flow boiling in microscale channelSalakij, Saran 25 March 2014 (has links)
In-situ vapor extraction is performed by applying a pressure differential across a hydrophobic porous membrane that forms a wall of the channel as a means of reducing the local quality of flow boiling within the channel. As the local quality is reduced, the heat transfer capability can be improve while large pressure drops and flow instability can be mitigated. The present study investigates the potential of vapor extraction, by examining the characteristics and mechanisms of extraction. The physics based models for transition among extraction regimes are developed which can be used as a basis for a regime-based vapor extraction rate model. The effects of vapor extraction on flow boiling in a microscale fractal-like branching network and diverging channels are studied by using a one-dimensional numerical model based on conservation of mass and energy, along with heat transfer and pressure drop correlations. The results show the improvement in reduced pressure drop and enhanced flow stability, and show the potential of heat transfer enhancement. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from March 25, 2013 - March 25, 2014
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Monitoring, characterizing, and preventing microbial degradation of ignitable liquids on soilTurner, Dee Ann January 2013 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Organic-rich substrates such as soil provide an excellent carbon source for bacteria. However, hydrocarbons such as those found in various ignitable liquids can also serve as a source of carbon to support bacterial growth. This is problematic for fire debris analysis as samples may be stored at room temperature for extended periods before they are analyzed due to case backlog. As a result, selective loss of key components due to bacterial metabolism can make identifying and classifying ignitable liquid residues by their chemical composition and boiling point range very difficult. The ultimate goal of this project is to preserve ignitable liquid residues against microbial degradation as efficiently and quickly as possible. Field and laboratory studies were conducted to monitor microbial degradation of gasoline and other ignitable liquids in soil samples. In addition to monitoring degradation in potting soil, as a worst case scenario, the effect of soil type and season were also studied. The effect of microbial action was also compared to the effect of weathering by evaporation (under nitrogen in the laboratory and by the passive headspace analysis of the glass fragments from the incendiary devices in the field studies). All studies showed that microbial degradation resulted in the significant loss of n-alkanes and lesser substituted alkylbenzenes predominantly and quickly, while more highly substituted alkanes and aromatics were not significantly affected. Additionally, the residential soil during the fall season showed the most significant loss of these compounds over the course of 30 days. To combat this problem, a chemical solution is to be immediately applied to the samples as they are collected. Various household and commercial products were tested for their efficacy at low concentrations to eliminate all living bacteria in the soil. Triclosan (2% (w/v) in NaOH) proved to be the most effective at preserving ignitable liquid residues for at least 30 days.
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