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Phase equilibria study of systems composed of refined babassu oil, lauric acid, ethanol, and water at 303.2 K

REIPERT, Erika C. D`Anton; RODRIGUES, Christianne E. C.; MEIRELLES, Antonio J. A.
Fonte: ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD Publicador: ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
76.33%
Deacidification of vegetable oils can be performed using liquid-liquid extraction as an alternative method to the classical chemical and physical refining processes. This paper reports experimental data for systems containing refined babassu oil, lauric acid, ethanol, and water at 303.2 K with different water mass fractions in the alcoholic solvent (0, 0.0557, 0.1045, 0.2029, and 0.2972). The dilution of solvent with water reduced the distribution coefficient values, which indicates a reduction in the loss of neutral oil. The experimental data were used to adjust the NRTL equation parameters. The global deviation between the observed and the estimated compositions was 0.0085, indicating that the model can accurately predict the behavior of the compounds at different levels of solvent hydration. (C) 2011 Elsevier Ltd. All rights reserved.; FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo)[09/17855-3]; FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo)[08/56258-8]; CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico); FINEP (Financiadora de Estudos e Projetos); CAPES (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior)

Liquid-liquid equilibria for systems composed of refined soybean oil, free fatty acids, ethanol, and water at different temperatures

CHIYODA, Cristina; PEIXOTO, Elaine C. D.; MEIRELLES, Antonio J. A.; RODRIGUES, Christianne E. C.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
76.34%
Soybean oil can be deacidified by liquid-liquid extraction with ethanol. In the present paper, the liquid-liquid equilibria of systems composed of refined soybean oil, commercial linoleic acid, ethanol and water were investigated at 298.2 K. The experimental data set obtained from the present study (at 298.2 K) and the results of Mohsen-Nia et al. [1] (at 303.2 K) and Rodrigues et al. [2] (at 323.2 K) were correlated by applying the non-random two liquid (NRTL) model. The results of the present study indicated that the mutual solubility of the compounds decreased with an increase in the water content of the solvent and a decrease in the temperature of the solution. Among variables, the water content of the solvent had the strongest effect on the solubility of the components. The maximum deviation and average variance between the experimental and calculated compositions were 1.60% and 0.89%, indicating that the model could accurately predict the behavior of the compounds at different temperatures and degrees of hydration. (C) 2010 Elsevier B.V. All rights reserved.; FAPESP (Fundacao de Amparo Pesquisa do Estado de Sao Paulo)[09/17855-3]; FAPESP (Fundacao de Amparo Pesquisa do Estado de Sao Paulo)[08/53095-2]; FAPESP (Fundacao de Amparo Pesquisa do Estado de Sao Paulo)[08/07326-0]; FAPESP (Fundacao de Amparo Pesquisa do Estado de Sao Paulo)[06/00565-4]; FAPESP (Fundacao de Amparo Pesquisa do Estado de Sao Paulo)[05/53095-2]; CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico); FINEP (Financiadora de Estudos e Projetos); CAPES (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior)

Simultaneous Quantification of Lycopene, beta-Carotene, Retinol and alpha-Tocopherol in Plasma after a Simple Extraction Procedure: Stability Study and Application to Human Volunteers

Charao, Mariele F.; Moro, Angela M.; Brucker, Natalia; Bulcao, Rachel P.; Baierle, Marilia; Freitas, Fernando; Durgante, Juliano; Nascimento, Sabrina; Bubols, Guilherme B.; Saldiva, Paulo Hilario Nascimento; Bohrere, Denise; Garcia, Solange C.
Fonte: SOC BRASILEIRA QUIMICA; SAO PAULO Publicador: SOC BRASILEIRA QUIMICA; SAO PAULO
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
86.25%
A method for the simultaneous quantification of lycopene, beta-carotene, retinol and alpha-tocopherol by high-performance liquid chromatography (HPLC) with Vis/fluorescence detection with isocratic elution was optimized and validated. The method consists of a rapid and simple liquid-liquid extraction procedure and a posterior quantification of extracted supernatants by HPLC. Aliquots of plasma were stored at -20 degrees C for three months for stability study. The methodology was applied to samples from painters and individuals not exposed to paints (n = 75). The assay was linear for all vitamins (r > 0.99). Intra-and inter-run precisions were obtained with coefficient of variation smaller than 5%. The accuracies ranged from 0.29 to -5.80% and recoveries between 92.73 and 101.97%. Plasma samples and extracted supernatants were stable for 60 days at -20 degrees C. A significant decrease of lycopene, beta-carotene and retinol concentrations in plasma from exposed individuals compared to non-exposed individuals (p < 0.05) was observed. The method is simple, reproducible, precise, accurate and sensitive, and can be routinely utilized in clinical laboratories.; Um método para quantificação simultânea de licopeno, β-caroteno, retinol e α-tocoferol por cromatografia líquida de alta eficiência (HPLC) com detecção no visível/fluorescente e eluição isocrática foi otimizado e validado. O método consiste de extração líquido-líquido rápida e simples e posterior quantificação do sobrenadante extraído por HPLC. Alíquotas de plasma foram estocadas a –20°C por três meses para estudo da estabilidade. Aplicação metodológica foi realizada em amostras fornecidas por pintores e indivíduos não expostos a tintas (n = 75). O ensaio foi linear para todas as vitaminas analisadas (r > 0...

Simultaneous quantification of lycopene, β-carotene, retinol and α -tocopherol in plasma after a simple extraction procedure: stability study and application to human volunteers

Charão, Mariele F.; Moro, Angela M.; Brucker, Natália; Bulcão, Rachel P.; Baierle, Marília; Freitas, Fernando; Durgante, Juliano; Nascimento, Sabrina; Bubols, Guilherme B.; Saldiva, Paulo H.; Bohrer, Denise; Garcia, Solange C.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
86.23%
A method for the simultaneous quantification of lycopene, β-carotene, retinol and α-tocopherol by high-performance liquid chromatography (HPLC) with Vis/fluorescence detection with isocratic elution was optimized and validated. The method consists of a rapid and simple liquid-liquid extraction procedure and a posterior quantification of extracted supernatants by HPLC. Aliquots of plasma were stored at -20°C for three months for stability study. The methodology was applied to samples from painters and individuals not exposed to paints (n = 75). The assay was linear for all vitamins (r > 0.99). Intra- and inter-run precisions were obtained with coefficient of variation smaller than 5%. The accuracies ranged from 0.29 to -5.80% and recoveries between 92.73 and 101.97%. Plasma samples and extracted supernatants were stable for 60 days at -20°C. A significant decrease of lycopene, β-carotene and retinol concentrations in plasma from exposed individuals compared to non-exposed individuals (p < 0.05) was observed. The method is simple, reproducible, precise, accurate and sensitive, and can be routinely utilized in clinical laboratories.

Desenvolvimento da fase extratora SPME de poli(pirrol) e avaliação das técnicas SPME/LC e SBSE/LC para análises de antidepressivos em amostras de plasma; Developmento of polypyrrole SPME extraction phase and evaluation of the SPME/LC and SBSE/LC techniques to antidepressants plasma samples analyses

Chaves, Andréa Rodrigues
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 27/06/2008 PT
Relevância na Pesquisa
86.34%
A depressão em idosos é uma desordem persistente e recorrente, resultado do stress psicossocial ou efeito de doenças fisiológicas, que podem acarretar a desabilidade do indivíduo, aumento dos sintomas das doenças clínicas, na maior utilização dos serviços de saúde e altas taxas de suicídios.A monitorização terapêutica permite a ndividualização do regime de dosagem, assegurando a eficácia clínica e minimizando os efeitos adversos dos fármacos, prescritos na clínica. Os antidepressivos têm sido monitorados, pois, apresentam intervalos terapêuticos bem estabelecidos, ou seja, a maioria dos pacientes, que apresentam concentrações plasmáticas dentro deste intervalo fixo, tem as desordens psiquiátricas mantidas sob controle e efeitos adversos aceitáveis. Os antidepressivos tricíclicos (ADTs): imipramina, amitriptilina, nortriptilina e desipramina, embora eficazes e ainda muito utilizados, apresentam efeitos adversos, não desejáveis. Os antidepressivos, inibidores seletivos da recaptação de serotonina (SSRIs): citalopram, fluoxetina, paroxetina e sertralina, apresentam eficácia clínica comparável aos clássicos ADTs, mas destituídos dos efeitos adversos associados aos mesmos. Os métodos convencionais...

Desacidificação do oleo de farelo de arroz por extração liquido-liquido.; Desacidification of the oil of bran of rice for extration liquid-liquid.

Christianne Elisabete da Costa Rodrigues
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 04/05/2004 PT
Relevância na Pesquisa
76.37%
Este trabalho de pesquisa teve como objetivo o estudo do processo de desacidificação do óleo de farelo de arroz por extração líquido-líquido (ELL), em equipamento contínuo, utilizando como solvente etanol azeotrópico, bem como a determinação experimental e modelagem do equilíbrio de fases do sistema óleo de farelo de arroz / ácido graxo / solvente alcoólico. Este processo alternativo de desacidificação foi investigado sob a ótica de sua capacidade em minimizar a perda de óleo neutro, capacidade de extrair os ácidos graxos livres e capacidade de minimizar a perda de antioxidantes naturais, Y-orizanol, tocoferóis e tocotrienóis. Para se atingir os objetivos propostos, um amplo estudo do equilíbrio de fases de sistemas compostos por óleo de farelo de arroz e solvente alcoólico foi realizado. Os dados de equilíbrio foram correlacionados por modelos semi-empíricos descritivos (NRTL e UNIQUAC) e os parâmetros de interação binária obtidos foram utilizados para a predição do equilíbrio de fases e na simulação do processo de extração em equipamento contínuo. Dados de equilíbrio também foram analisados por metodologia de superfície de resposta (MSR). Esta análise permitiu o conhecimento da influência do teor de acidez no óleo e do teor de água no solvente etanólico sobre as perdas de óleo neutro...

Desacidificação de oleo de soja por extração liquido-liquido.; Deacidificationof soybean oil by liquid-liquid extraction.

Leticia Andrade de Sa
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 12/03/2007 PT
Relevância na Pesquisa
86.33%
O processo de desacidificação do óleo de soja por extração líquido-líquido (ELL) foi estudado em uma coluna de discos rotativos perfurados (PRDC), operada de modo contínuo e contra-corrente. Foram estudados sistemas-modelo formados por óleo de soja refinado com adição artificial de aproximadamente 2% de ácido linoléico comercial. Até o momento, os estudos de desacidificação de óleos vegetais por ELL realizados no Laboratório de Extração, Termodinâmica Aplicada e Equilíbrio (ExTrAE) haviam sido feitos com óleos que apresentavam teores mais altos de acidez (3 a 8%). O diferencial deste trabalho está no fato de o óleo de soja bruto apresentar baixa acidez (cerca de 2%). Outro diferencial foi a utilização de temperatura superior (50 °C) à ambiente e teor mais elevado de água no solvente, permitindo diminuir a perda de óleo neutro sem uma diminuição significativa da capacidade de o solvente extrair os ácidos graxos livres. Os experimentos foram analisados por metodologia de superfície de resposta, que permitiu avaliar a influência do teor de água no etanol (0 a 12% em massa) e da velocidade de rotação dos discos (50 a 150 rpm) na transferência de acidez e na perda de óleo neutro. Os resultados experimentais mostraram que é possível obter um óleo refinado com teor de acidez abaixo do exigido pela legislação (< 0...

Modelagem computacional para predição de equilibrio líquido-líquido de sistemas graxos; Computational modeling to predict liquid-liquid equilibrium of fatty systems

Gláucia de Freitas Hirata
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 25/02/2011 PT
Relevância na Pesquisa
76.06%
Na indústria de óleos, a remoção dos ácidos graxos livres é a etapa mais importante do processo de purificação. Geralmente, é realizada pelo refino químico ou físico. Em alguns casos, no entanto, o refino convencional provoca resultados indesejáveis. A desacidificação por extração líquido-líquido tem se mostrado uma alternativa viável tecnicamente. Nos estudos realizados, os dados de equilíbrio são determinados e modelados para cada tipo de óleo isoladamente, resultando em modelos que são específicos para cada óleo. No entanto, para obter uma ferramenta preditiva, é necessário considerar as verdadeiras composições presentes nas misturas para que se consiga distinguir o comportamento de cada tipo de sistema de forma satisfatória. Neste trabalho, os dados existentes na literatura foram usados para reajustar os parâmetros de interação entre grupos do método UNIFAC. Isto é necessário porque os parâmetros originais do UNIFAC-LLE não predizem bem o comportamento desse tipo de sistema. Para reajustar estes parâmetros, os sistemas foram modelados considerando sua complexidade. Entretanto, para conseguir comparar com os dados experimentais, as misturas foram consideradas pseudoternárias e pseudoquaternárias (como estão disponíveis os dados experimentais). Uma nova divisão também foi proposto para simplificar a descrição do pseudocomponente óleo. No caso...

Phase equilibria study of systems composed of refined babassu oil, lauric acid, ethanol, and water at 303.2 K

REIPERT, Erika C. D`Anton; RODRIGUES, Christianne E. C.; MEIRELLES, Antonio J. A.
Fonte: ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD Publicador: ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
76.25%
Deacidification of vegetable oils can be performed using liquid-liquid extraction as an alternative method to the classical chemical and physical refining processes. This paper reports experimental data for systems containing refined babassu oil, lauric acid, ethanol, and water at 303.2 K with different water mass fractions in the alcoholic solvent (0, 0.0557, 0.1045, 0.2029, and 0.2972). The dilution of solvent with water reduced the distribution coefficient values, which indicates a reduction in the loss of neutral oil. The experimental data were used to adjust the NRTL equation parameters. The global deviation between the observed and the estimated compositions was 0.0085, indicating that the model can accurately predict the behavior of the compounds at different levels of solvent hydration. (C) 2011 Elsevier Ltd. All rights reserved.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Liquid-liquid equilibria for systems composed of refined soybean oil, free fatty acids, ethanol, and water at different temperatures

CHIYODA, Cristina; PEIXOTO, Elaine C. D.; MEIRELLES, Antonio J. A.; RODRIGUES, Christianne E. C.
Fonte: ELSEVIER SCIENCE BV Publicador: ELSEVIER SCIENCE BV
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
76.29%
Soybean oil can be deacidified by liquid-liquid extraction with ethanol. In the present paper, the liquid-liquid equilibria of systems composed of refined soybean oil, commercial linoleic acid, ethanol and water were investigated at 298.2 K. The experimental data set obtained from the present study (at 298.2 K) and the results of Mohsen-Nia et al. [1] (at 303.2 K) and Rodrigues et al. [2] (at 323.2 K) were correlated by applying the non-random two liquid (NRTL) model. The results of the present study indicated that the mutual solubility of the compounds decreased with an increase in the water content of the solvent and a decrease in the temperature of the solution. Among variables, the water content of the solvent had the strongest effect on the solubility of the components. The maximum deviation and average variance between the experimental and calculated compositions were 1.60% and 0.89%, indicating that the model could accurately predict the behavior of the compounds at different temperatures and degrees of hydration. (C) 2010 Elsevier B.V. All rights reserved.; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Liquid-liquid extraction in the presence of electrolytes of nisin and green fluorescent protein (GFPuv)

Mazzola, Priscila Gava; Jozala, A. F.; Magalhães, Pérola de Oliveira; Pessoa Júnior, Adalberto; Penna, T. C. V.
Fonte: Universidade do Minho. Departamento de Engenharia Biológica Publicador: Universidade do Minho. Departamento de Engenharia Biológica
Tipo: Conferência ou Objeto de Conferência
Publicado em /09/2008 ENG
Relevância na Pesquisa
86.2%
In the biotechnology field, it has been suggested that extractions in two-phase aqueous complex-fluid systems can possibly be used instead of, or as complementary processes to, the more typical chromatographic operations, to reduce the cost of the downstream processing of many biological products (Lam et al., 2004; Mazzola et al., 2006). This method offer attractive conditions to be applied in this study, thereby two-phase systems can be exploited in separation science for the extraction/purification of desired biomolecules directly on the culture medium (Mazzola et al., 2008). This study aimed to evaluate the aqueous two phase system (ATPS) composed by a nonionic surfactant, Triton X-114 (TX), in presence or absence of electrolytes, to separate two interesting biomolecules: nisin and recombinant green fluorescent protein (GFP). Results indicated that nisin partitions preferentially to the micelle rich-phase, with significant antimicrobial activity increase (up to 10-fold). GFP partitioned evenly between the phases in TX system without electrolytes.; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Brazil (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brazil (CNPq); Fundação de Amparo à Pesquisa do Estado de São Paulo...

Use of solid-supported liquid-liquid extraction in the analysis of polyphenols in wine

Nave, Frederico; Cabrita, Maria Joao; Teixeira da Costa, Cristina
Fonte: Universidade de Évora Publicador: Universidade de Évora
Tipo: Artigo de Revista Científica Formato: 533929 bytes; application/pdf
ENG
Relevância na Pesquisa
76.33%
Solid-supported liquid–liquid extraction (SS-LLE) was compared to liquid–liquid extraction (LLE) for the analysis of phenolic compounds in wine. Diatomaceous earth commercial cartridges were evaluated together with “in-house” made cartridges for the wine phenolic extraction. Statistical treatment, analysis of variance ANOVA-single factor, was used to compare the extraction yields obtained by these methods, and for the majority of the studied compounds, significantly higher yields were obtained by the SS-LLE methodology using the “in-house” prepared cartridges. This is an environmentally friendly low-cost sample preparation method which proved to be reproducible (RSD < 5% for the most compounds) and yielding high recoveries (80–100%) for the compounds studied.

Simultaneous quantification of lycopene, β-carotene, retinol and α -tocopherol in plasma after a simple extraction procedure: stability study and application to human volunteers

Charão,Mariele F.; Moro,Angela M.; Brucker,Natália; Bulcão,Rachel P.; Baierle,Marília; Freitas,Fernando; Durgante,Juliano; Nascimento,Sabrina; Bubols,Guilherme B.; Saldiva,Paulo H.; Bohrer,Denise; Garcia,Solange C.
Fonte: Sociedade Brasileira de Química Publicador: Sociedade Brasileira de Química
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/08/2012 EN
Relevância na Pesquisa
86.23%
A method for the simultaneous quantification of lycopene, β-carotene, retinol and α-tocopherol by high-performance liquid chromatography (HPLC) with Vis/fluorescence detection with isocratic elution was optimized and validated. The method consists of a rapid and simple liquid-liquid extraction procedure and a posterior quantification of extracted supernatants by HPLC. Aliquots of plasma were stored at -20°C for three months for stability study. The methodology was applied to samples from painters and individuals not exposed to paints (n = 75). The assay was linear for all vitamins (r > 0.99). Intra- and inter-run precisions were obtained with coefficient of variation smaller than 5%. The accuracies ranged from 0.29 to -5.80% and recoveries between 92.73 and 101.97%. Plasma samples and extracted supernatants were stable for 60 days at -20°C. A significant decrease of lycopene, β-carotene and retinol concentrations in plasma from exposed individuals compared to non-exposed individuals (p < 0.05) was observed. The method is simple, reproducible, precise, accurate and sensitive, and can be routinely utilized in clinical laboratories.

Liquid-liquid extraction by reversed micelles in biotechnological processes

Kilikian,B. V.; Bastazin,M. R.; Minami,N. M.; Gonçalves,E. M. R.; Junior,A. P.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/03/2000 EN
Relevância na Pesquisa
86.33%
In biotechnology there is a need for new purification and concentration processes for biologically active compounds such as proteins, enzymes, nucleic acids, or cells that combine a high selectivity and biocompatibility with an easy scale-up. A liquid-liquid extraction with a reversed micellar phase might serve these purposes owing to its capacity to solubilize specific biomolecules from dilute aqueous solutions such as fermentation and cell culture media. Reversed micelles are aggregates of surfactant molecules containing an inner core of water molecules, dispersed in a continuous organic solvent medium. These reversed micelles are capable of selectively solubilizing polar compounds in an apolar solvent. This review gives an overview of liquid-liquid extraction by reversed micelles for a better understanding of this process.

Liquid-liquid equilibrium of water + PEG 8000 + magnesium sulfate or sodium sulfate aqueous two-phase systems at 35°C: experimental determination and thermodynamic modeling

Castro,B. D.; Aznar,M.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2005 EN
Relevância na Pesquisa
76.07%
Liquid-liquid extraction using aqueous two-phase systems is a highly efficient technique for separation and purification of biomolecules due to the mild properties of both liquid phases. Reliable data on the phase behavior of these systems are essential for the design and operation of new separation processes; several authors reported phase diagrams for polymer-polymer systems, but data on polymer-salt systems are still relatively scarce. In this work, experimental liquid-liquid equilibrium data on water + polyethylene glycol 8000 + magnesium sulfate and water + polyethylene glycol 8000 + sodium sulfate aqueous two-phase systems were obtained at 35°C. Both equilibrium phases were analyzed by lyophilization and ashing. Experimental results were correlated with a mass-fraction-based NRTL activity coefficient model. New interaction parameters were estimated with the Simplex method. The mean deviations between the experimental and calculated compositions in both equilibrium phases is about 2%.

Liquid - liquid extraction of matrine using TRPO/cyclohexane reverse micelles

Dong,Lichun; Li,Wenping; Zhou,Xiaohua; Kang,Qin; Shen,Weifeng
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2009 EN
Relevância na Pesquisa
126.24%
Reverse micellar extraction has been widely used in the purification of biomolecules. However, reverse micelles formed by ionic surfactants can only be employed for the extraction of biomolecules that are charged in the extraction system with the electrostatic interaction between surfactants and solutes as the driving force. In this study, the extraction of matrine by using reverse micelles formed by non-ionic TRPO surfactants was studied. Theoretical analysis and experimental results demonstrated that the driving force of the extraction is the coordination forces between matrines and TRPOs. Using this coordination-based reverse micellar extraction, matrine can be efficiently separated from oxymatrine and other components in the raw matrine materials. Experimental studies showed that the factors affecting matrine extraction include pH value and TRPO concentration. The existence of ions in the system does not affect the partition coefficient significantly and the addition of a small amount of chloroform in the solution of reverse micelles was found to improve the extraction significantly.

Liquid-Liquid Extraction for Recovery of Paclitaxel from Plant Cell Culture: Solvent Evaluation and Use of Extractants for Partitioning and Selectivity

McPartland, Timothy J.; Patil, Rohan A.; Malone, Michael F.; Roberts, Susan C.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
76.25%
A major challenge in the production of metabolites by plant cells is the separation and purification of a desired product from a number of impurities. An important application of plant cell culture is the biosynthesis of the anti-cancer agent paclitaxel. Liquid-liquid extraction plays a critical role in the recovery of paclitaxel and other valuable plant-derived products from culture broth. In this study, the extraction of paclitaxel and a major unwanted by-product, cephalomannine, from plant cell culture broth into organic solvents is quantified. Potential solvent mixtures show varying affinity and selectivity for paclitaxel over cephalomannine. The partition coefficient of paclitaxel is highest in ethyl acetate and dichloromethane, with measured values of 28 and 25, respectively; however selectivity coefficients are less than 1 for paclitaxel over cephalomannine for both solvents. Selectivity coefficient increases to 1.7 with extraction in n-hexane but the partition coefficient decreases to 1.9. Altering the pH of the aqueous phase results in an increase in both recovery and selectivity using n-hexane, but does not change the results for other solvents significantly. The addition of extractants trioctyl amine (TOA) or tributyl phosphate (TBP) to n-hexane gives significantly higher partition coefficients for paclitaxel (8.6 and 23.7...

Stir bar-sorptive extraction, solid phase extraction and liquid-liquid extraction for levetiracetam determination in human plasma: comparing recovery rates

Freitas-Lima, Priscila; Ferreira, Flavia Isaura Santi; Bertucci, Carlo; Alexandre Júnior, Veriano; Dreossi, Sônia Aparecida Carvalho; Pereira, Leonardo Regis Leira; Sakamoto, Américo Ceiki; Queiroz, Regina Helena Costa
Fonte: Universidade de São Paulo. Faculdade de Ciências Farmacêuticas Publicador: Universidade de São Paulo. Faculdade de Ciências Farmacêuticas
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; ; Formato: application/pdf
Publicado em 01/06/2015 ENG
Relevância na Pesquisa
76.35%
Levetiracetam (LEV), an antiepileptic drug (AED) with favorable pharmacokinetic profile, is increasingly being used in clinical practice, although information on its metabolism and disposition are still being generated. Therefore a simple, robust and fast liquid-liquid extraction (LLE) followed by high-performance liquid chromatography method is described that could be used for both pharmacokinetic and therapeutic drug monitoring (TDM) purposes. Moreover, recovery rates of LEV in plasma were compared among LLE, stir bar-sorptive extraction (SBSE), and solid-phase extraction (SPE). Solvent extraction with dichloromethane yielded a plasma residue free from usual interferences such as commonly co-prescribed AEDs, and recoveries around 90% (LLE), 60% (SPE) and 10% (SBSE). Separation was obtained using reverse phase Select B column with ultraviolet detection (235 nm). Mobile phase consisted of methanol:sodium acetate buffer 0.125 M pH 4.4 (20:80, v/v). The method was linear over a range of 2.8-220.0 µg mL;-1;. The intra- and inter-assay precision and accuracy were studied at three concentrations; relative standard deviation was less than 10%. The limit of quantification was 2.8 µg mL;-1;. This robust method was successfully applied to analyze plasma samples from patients with epilepsy and therefore might be used for pharmacokinetic and TDM purposes.; ;Levetiracetam...

Pressurized liquid extraction of selected molecular biomarkers in deep sea sediments used as proxies in paleoceanography

Calvo, Eva; Pelejero, Carles; Logan, Graham A
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
96.41%
Pressurized liquid extraction has been performed on a suite of deep-sea sediments to assess its capability as an extraction technique in the analysis of molecular biomarkers used in paleoceanography. Specific compounds assessed comprise long-chain alkenones, n-alkanes, n-alcohols and, additionally, one diol and one keto-ol. These have been extracted by both pressurized liquid extraction and ultrasonication for comparison. One key result is that the U37K′ index (based on the degree of unsaturation of the alkenones and used as a paleothermometer in paleoceanography) remains intact after both extraction techniques. In terms of biomarker concentrations, which are often used to qualitatively assess changes in marine productivity and/or terrigenous inputs, pressurized liquid extraction is substantially more efficient than ultrasonication, providing higher amounts of extracted constituents, particularly for polar compounds.

Liquid-Liquid Extraction of Platinum from Chloride Media by N,N'-Dimethyl-N,N'-Dicyclohexyltetradecylmalonamide

Costa, M. Clara; Assunção, Ana; Costa, Ana M. Rosa da; Nogueira, C. A.; Paiva, A. P.
Fonte: Taylor & Francis Publicador: Taylor & Francis
Tipo: Artigo de Revista Científica
Publicado em //2013 ENG
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Liquid-liquid extraction of platinum(IV) from chloride media was carried out using N,N'-dimethyl-N,N'-dicyclohexyltetradecylmalonamide (DMDCHTDMA) in 1,2-dichloroethane. Platinum can be effectively extracted by DMDCHTDMA without addition of tin(II) chloride, since extraction percentages (%E) of 88% and 99% have been achieved from 6 M and 8 M HCl, respectively. Moreover, platinum can be successfully stripped through a simple contact with a 1 M HCl solution. The effect of some experimental parameters such as equilibration time, diluent, extractant and HCl concentrations was systematically investigated. The loading capacity of DMDCHTDMA was also evaluated. Data obtained from successive extraction-stripping cycles suggest a good stability pattern of DMDCHTDMA. Preliminary extraction data achieved with single metal ion solutions pointed out to a possible separation of platinum(IV) from palladium(II).