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New Calibration Approaches in Solid Phase Microextraction for On-Site AnalysisChen, Yong January 2004 (has links)
Calibration methods for quantitative on-site sampling using solid phase microextraction (SPME) were developed based on diffusion mass transfer theory. This was investigated using adsorptive polydimethylsiloxane/divinylbenzene (PDMS/DVB) and Carboxen/polydimethylsiloxane (CAR/PDMS) SPME fiber coatings with volatile aromatic hydrocarbons (BTEX: benzene, toluene, ethylbenzene, and o-xylene) as test analytes. Parameters that affected the extraction process (sampling time, analyte concentration, water velocity, and temperature) were investigated. Very short sampling times (10-300 s) and sorbents with a strong affinity and large capacity were used to ensure a 'zero sink' effect calibrate process. It was found that mass uptake of analyte changed linearly with concentration. Increase of water velocity increased mass uptake, though the increase is not linear. Temperature did not affect mass uptake significantly under typical field sampling conditions. To further describe rapid SPME analysis of aqueous samples, a new model translated from heat transfer to a circular cylinder in cross flow was used. An empirical correlation to this model was used to predict the mass transfer coefficient. Findings indicated that the predicted mass uptake compared well with experimental mass uptake. The new model also predicted rapid air sampling accurately. To further integrate the sampling and analysis processes, especially for on-site or <i>in-vivo</i> investigations where the composition of the sample matrix is very complicated and/or agitation of the sample matrix is variable or unknown, a new approach for calibration was developed. This involved the loading internal standards onto the extraction fiber prior to the extraction step. During sampling, the standard partially desorbs into the sample matrix and the rate at which this process occurs, was for calibration. The kinetics of the absorption/desorption was investigated, and the isotropy of the two processes was demonstrated, thus validating this approach for calibration. A modified SPME device was used as a passive sampler to determine the time-weighted average (TWA) concentration of volatile organic compounds (VOCs) in air. The sampler collects the VOCs by the mechanism of molecular diffusion and sorption on to a coated fiber as collection medium. This process was shown to be described by Fick's first law of diffusion, whereby the amount of analyte accumulated over time enable measurement of the TWA concentration to which the sampler was exposed. TWA passive sampling with a SPME device was shown to be almost independent of face velocity, and to be more tolerant of high and low analyte concentrations and long and short sampling times, because of the ease with which the diffusional path length could be changed. Environmental conditions (temperature, pressure, relative humidity, and ozone) had little or no effect on sampling rate. When the SPME device was tested in the field and the results compared with those from National Institute of Occupational Health and Safety (NIOSH) method 1501 good agreement was obtained. To facilitate the use of SPME for field sampling, a new field sampler was designed and tested. The sampler was versatile and user-friendly. The SPME fiber can be positioned precisely inside the needle for TWA sampling, or exposed completely outside the needle for rapid sampling. The needle is protected within a shield at all times hereby eliminating the risk of operator injury and fiber damage. A replaceable Teflon cap is used to seal the needle to preserve sample integrity. Factors that affect the preservation of sample integrity (sorbent efficiency, temperature, and sealing materials) were studied. The use of a highly efficient sorbent is recommended as the first choice for the preservation of sample integrity. Teflon was a good material for sealing the fiber needle, had little memory effect, and could be used repeatedly. To address adsorption of high boiling point compounds on fiber needles, several kinds of deactivated needles were evaluated. RSC-2 blue fiber needles were the more effective. A preliminary field sampling investigation demonstrated the validity of the new SPME device for field applications.
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New Calibration Approaches in Solid Phase Microextraction for On-Site AnalysisChen, Yong January 2004 (has links)
Calibration methods for quantitative on-site sampling using solid phase microextraction (SPME) were developed based on diffusion mass transfer theory. This was investigated using adsorptive polydimethylsiloxane/divinylbenzene (PDMS/DVB) and Carboxen/polydimethylsiloxane (CAR/PDMS) SPME fiber coatings with volatile aromatic hydrocarbons (BTEX: benzene, toluene, ethylbenzene, and o-xylene) as test analytes. Parameters that affected the extraction process (sampling time, analyte concentration, water velocity, and temperature) were investigated. Very short sampling times (10-300 s) and sorbents with a strong affinity and large capacity were used to ensure a 'zero sink' effect calibrate process. It was found that mass uptake of analyte changed linearly with concentration. Increase of water velocity increased mass uptake, though the increase is not linear. Temperature did not affect mass uptake significantly under typical field sampling conditions. To further describe rapid SPME analysis of aqueous samples, a new model translated from heat transfer to a circular cylinder in cross flow was used. An empirical correlation to this model was used to predict the mass transfer coefficient. Findings indicated that the predicted mass uptake compared well with experimental mass uptake. The new model also predicted rapid air sampling accurately. To further integrate the sampling and analysis processes, especially for on-site or <i>in-vivo</i> investigations where the composition of the sample matrix is very complicated and/or agitation of the sample matrix is variable or unknown, a new approach for calibration was developed. This involved the loading internal standards onto the extraction fiber prior to the extraction step. During sampling, the standard partially desorbs into the sample matrix and the rate at which this process occurs, was for calibration. The kinetics of the absorption/desorption was investigated, and the isotropy of the two processes was demonstrated, thus validating this approach for calibration. A modified SPME device was used as a passive sampler to determine the time-weighted average (TWA) concentration of volatile organic compounds (VOCs) in air. The sampler collects the VOCs by the mechanism of molecular diffusion and sorption on to a coated fiber as collection medium. This process was shown to be described by Fick's first law of diffusion, whereby the amount of analyte accumulated over time enable measurement of the TWA concentration to which the sampler was exposed. TWA passive sampling with a SPME device was shown to be almost independent of face velocity, and to be more tolerant of high and low analyte concentrations and long and short sampling times, because of the ease with which the diffusional path length could be changed. Environmental conditions (temperature, pressure, relative humidity, and ozone) had little or no effect on sampling rate. When the SPME device was tested in the field and the results compared with those from National Institute of Occupational Health and Safety (NIOSH) method 1501 good agreement was obtained. To facilitate the use of SPME for field sampling, a new field sampler was designed and tested. The sampler was versatile and user-friendly. The SPME fiber can be positioned precisely inside the needle for TWA sampling, or exposed completely outside the needle for rapid sampling. The needle is protected within a shield at all times hereby eliminating the risk of operator injury and fiber damage. A replaceable Teflon cap is used to seal the needle to preserve sample integrity. Factors that affect the preservation of sample integrity (sorbent efficiency, temperature, and sealing materials) were studied. The use of a highly efficient sorbent is recommended as the first choice for the preservation of sample integrity. Teflon was a good material for sealing the fiber needle, had little memory effect, and could be used repeatedly. To address adsorption of high boiling point compounds on fiber needles, several kinds of deactivated needles were evaluated. RSC-2 blue fiber needles were the more effective. A preliminary field sampling investigation demonstrated the validity of the new SPME device for field applications.
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The Study of Binding Behaviors between Dissolved Organic Matter and Polycyclic Aromatic CompoundsHsieh, Ping-Chieh 23 June 2011 (has links)
Polycyclic aromatic hydrocarbons (PAHs) and nitrogen-containing polycyclic aromatic compound (N-PAC) are widespread toxic pollutants in environments. The fate of PAHs and N-PACs are of great concern because some of these compounds were identified as caricinogenic, mutagenic and teratogenic compounds. As described in literature, dissolved organic matter (DOM) is an important factor in control of their fate; however, the binding behaviors between these compounds and DOM are still not fully understood. The binding constants (KDOC) between humic substances and one selected N-PAC, benzo[h]quinoline, were measured at varying pH levels using fluorescence quenching (FQ) method. As fluorescence characteristics of benzo[h]quinoline change with pH, determination required two optimum sets of excitation and emission wavelength pairs. A simple mixing model was proposed and used to eliminate the inherent fluorescence interference between benzo[h]quinoline (BQ) and its protonated form, benzo[h]quinolinium (BQH+), and to deduce Kmix which represents the overall binding as the sum of that for the individual analogs. The characteristics of humic substances, especially their hydrophobicity and aromaticity, established by principal components analysis of structural and elemental compositions, were the main determinants of their binding affinity with both benzo[h]quinoline and benzo[h]quinolinium (KBQ and KBQH+) across a range of pH values. Hydrophobic interaction is likely to control the binding between humic substance and benzo[h]quinoline and benzo[h]quinolinium, in lower and higher pH ranges (pH<3, pH>6). In contrast, cation exchange seems to control on the binding affinity of benzo[h]quinolinium in the middle range of pH.
Determination of PAH concentration is quite essential for investigating the fate of PAHs in environments. Microwave-assisted headspace solid-phase microextraction (MA-HS-SPME) with a polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber was applied as a single step prior to determination of PAH concentrations in water using GC-MS. To optimize the extraction efficiency of PAHs by MA-HS-SPME, the influence of various parameters, including temperature, duration of thermal desorption, microwave irradiation power and duration, and the temperature of the circulating cooling water system, was studied. The proposed method was demonstrated applicable to environmental water samples. In addition, DOM matrix effect did not influence the determination and extraction efficiency of PAHs.
Although the proposed simple mixing model can eliminate the fluorescent interference of hydrophobic organic compounds with acid-base pair forms, it is still limited in using for correcting the KDOC measurement of more than two fluorescent compounds simultaneously. A new alternative protocol, complexation-flocculation combined with MA-HS-SPME/GC-MS method, was proposed to determine the binding constants of seleted PAHs to humic substances. The results obtained are comparable with KDOC data reported in literatures. CF-MA-HS-SPME/GC-MS provides some advantages over other methods, such as applicable not limited to fluorescent compounds, faster in determination and capable in measuring varieties of compounds simultaneously.
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A Novel Miniaturised Dynamic Hollow-Fibre Liquid-Phase Micro-Extraction Method for Xenobiotics in Human Plasma SamplesHansson, Helena January 2010 (has links)
Bioanalytical chemistry is a challenging field, often involving complex samples, such as blood, plasma, serum or urine. In many applications, sample cleanup is the most demanding and time-consuming step. In the work underlying this thesis a novel dynamic miniature extractor, known as a hollow-fibre liquid-phase microextractor (HF-LPME), was designed, evaluated and studied closely when used to clean plasma samples. Aqueous-organic-aqueous liquid extraction, in which the organic liquid is immobilised in a porous polypropylene membrane, was the principle upon which the extractor was based, and this is discussed in all the papers associated with this thesis. This type of extraction is known as supported-liquid membrane extraction (SLM). The aim of this work was the development of a dynamic system for SLM. It was essential that the system could handle small sample volumes and had the potential for hyphenations and on-line connections to, for instance, LC/electrospray-MS. The design of a miniaturised HF-LPME device is presented in Paper I. The extraction method was developed for some weakly acidic pesticides and these were also used for evaluation. In the work described in Paper II, the method was optimised on the basis of an experimental design using spiked human plasma samples. Paper III presents a detailed study of the mass-transfer over the liquid membrane. The diffusion through the membrane pores was illustrated by a computer-simulation. Not surprisingly, the more lipophilic, the greater the retention of the compounds, as a result of dispersive forces. The main focus of the work described in Paper IV was to make the HF/LPME system more versatile and user-friendly; therefore, the extractor was automated by hyphenation to a SIA system. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Manuscript.
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Effect of Thermal Processing and Pressure Assisted Thermal Processing (PATP) on the Flavor Profile of Conjugated Linoleic Acid (CLA)-Enriched MilkLeal Davila, Metzeri Unknown Date
No description available.
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In vivo Solid Phase Microextraction for Brain Tissue AnalysisCudjoe, Erasmus January 2014 (has links)
New solid phase microextraction (SPME) method was developed for brain tissue bioanalysis on a liquid chromatography mass spectrometry platform.
To achieve set objectives, in vivo SPME desorption process was optimized for high throughput analysis through the development of a desorption device. Subsequently, new SPME coatings were developed for the extraction of polar neurotransmitters from biological matrices. In a targeted analysis, in vivo SPME was used to monitor of changes in the concentrations of endogenous compounds (multiple neurotransmitters) and exogenous drugs (carbamazepine and cimetidine) in the striatum of the rat brain extracellular fluid. For the first time, SPME was used for quantitative analysis of neurotransmitters and also study spacial distribution of other drugs in different regions of the brain extracellular fluid.
A new approach was developed for improved metabolites coverage in a global non-targeted metabolomics studies. The proposed in vivo method showed how complementary results can be obtained through the combination of microdialysis and SPME for simultaneous sampling of the brain extracellular fluid.
Finally, in a clinical application, SPME was used to monitor changes in the concentration of multiple neurotransmitters during deep brain stimulation of the pre-frontal cortex of the brain.
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Isoflurano : desenvolvimento de um método analítico empregando microextração em fase sólida, incorporação em nanoemulsões e avaliação biológica das nanoemulsõesKrahn, Carolina Lopes January 2010 (has links)
O objetivo do presente trabalho foi desenvolver e validar um método analítico empregando microextração em fase sólida (SPME) para detecção e quantificação de isoflurano (ISO) na forma volátil e incluso em nanoemulsões intravenosas e, ainda, avaliar o efeito biológico destas. A detecção do ISO foi realizada através de cromatografia em fase gasosa com detector de ionização de chama (CG/DIC). As condições ideais para realização da pré-concentração e extração de ISO através da técnica de SPME foram temperatura ambiente, agitação constante, 30 min de extração e 2 min de dessorção no injetor do CG. O método desenvolvido foi validado avaliando os parâmetros de especificidade, linearidade, limites de detecção e quantificação, precisão, exatidão e robustez. As nanoemulsões contendo ISO foram desenvolvidas através da homogeneização à alta pressão, e apresentaram diâmetro médio, índice de polidispersão, potencial zeta e pH de 150 ± 0,78 nm, 0,08 ± 0,01, - 18 ± 2,4 mV e 6,03 ± 0,04, respectivamente. O pH foi ajustado para 7,4 (valor fisiológico). O teor de ISO nas formulações foi de 98,4 %. Não houve modificação das características físico-químicas das nanoemulsões após 30 dias de armazenamento a 8 ºC. Análises de espalhamento de luz múltiplo não demonstraram tendência a fenômenos de instabilidade física para as formulações. Os estudos do efeito anestésico das nanoemulsões intravenosas contendo ISO em cães evidenciaram uma redução significativa (p < 0,05) na dose comparada com a administração de ISO volátil. Não houve alterações no débito cardíaco, saturação de oxigênio na hemoglobina e nos biomarcadores das funções renal, hepática e muscular. Uma queda na pressão arterial dos cães foi observada em todos os tratamentos devido ao efeito hipotensor do ISO. Após administração das nanoemulsões contendo ISO e branca, observou-se taquipnéia, edema, eritema, e baixas concentrações de dióxido de carbono expiradas. Assim, a nanoemulsificação do ISO foi realizada com sucesso e a aplicação na anestesia geral intravenosa foi demonstrada. / The aims of this work were to develop and validate an analytical method using solidphase microextraction (SPME) to detect and quantify isoflurane (ISO) inhalation liquid and loaded in intravenous nanoemulsions, and also evaluate the biological effect of the formulations. ISO detection was made by gas chromatography with flame ionization detector (GC/FID). The ideal conditions setting for the pre concentration and extraction of ISO through SPME were environmental temperature, constant stirring, 30 min for extraction and 2 min for analyte desorption in the GC inlet port. The developed method was validated by means of specificity, linearity, detection and quantification limits, precision, accuracy and robustness. The ISOloaded nanoemulsions were formulated by high-pressure homogenization, and presented average diameter, polydispersity index, zeta potential and pH of 150 ± 0.78 nm, 0.08 ± 0.01, -18 ± 2.4 mV and 6.03 ± 0.04, respectively. The pH was adjusted to 7.4 (physiological value). The drug content on the formulations was 98.4 %. After 30 days of storage at 8 ºC no changes on nanoemulsion’s physicalchemical characteristics were observed. Multiple light scattering analysis did not demonstrate any physical destabilization phenomena for the formulations. The anesthetic effect study for the intravenous ISO-loaded nanoemulsions in dogs highlighted a significant reduction (p < 0.05) in dosage regimen when compared to the volatile ISO administration. There were no alterations on cardiac rate, oxygen hemoglobin saturation and on biomarkers of the renal, hepatic and muscle functionalities. A decrease in dog’s arterial blood pressure in all treatments due the hypotensive effect caused by ISO was observed. After the administration of the nanomulsions, ISO-loaded and unloaded, occurred tachypnea, edema, erythema and low end tidal concentrations of carbon dioxide. Taking all above into account, the method was considered easy on execution and suitable for laboratory routines, the ISO nanoemulsification was made successfully and its application on general anesthesia was demonstrated.
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Desenvolvimento de estratégias analíticas envolvendo microextração dispersiva e sistema em linha empregando extração no ponto-nuvem para a determinação de metaisBaliza, Patrícia Xavier 05 1900 (has links)
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Tese-Paty.pdf: 1034475 bytes, checksum: 37ed961306f75730b2da341693d7846e (MD5) / FAPESB / No presente trabalho, é proposta a síntese de um novo reagente
derivado do tiazol, o 5-bromotiazolilazo-2-orcinol (Br-TAO) e a sua aplicação
em sistemas de pré-concentração de metais. O Br-TAO foi empregado em um
procedimento para a pré-concentração de cobalto utilizando a micro-extração
dispersiva líquido-líquido e determinação por espectrometria de absorção
atômica com chama (FAAS). O fator de enriquecimento e o limite de detecção
obtidos foram 16 e 0,9 µg L-1, respectivamente. A exatidão do método foi
testada por análise do material de referência certificado NIST 1570a, Folhas de
Espinafre. Este procedimento foi aplicado para a determinação de cobalto em
águas do Rio das Contas, localizado no município de Jequié-BA. Outro
procedimento empregou o reagente Br-TAO em um sistema em linha com
injeção seqüencial e extração no ponto-nuvem para pré-concentração e
determinação de manganês por FAAS. O procedimento foi baseado na
extração no ponto-nuvem de manganês no sistema de injeção seqüencial e
retenção em minicoluna, com posterior eluição e detecção. Variáveis químicas
e de fluxo que influenciam o sistema foram otimizadas e alguns parâmetros
analíticos determinados, como freqüência analítica (48 h-1), fator de
enriquecimento (14), índice de consumo (0,20 mL) e limite de detecção (0,5 µg
L-1). Os materiais de referência certificados NIST 1568a, Farinha de Arroz e
NIST 1573a, Folhas de Tomateiro, foram utilizados para o teste da exatidão do
procedimento. O método foi aplicado à determinação de manganês em farinhas
de arroz, láctea e de milho. Este trabalho faz parte de um projeto PRONEX,
financiado pelo CNPq/FAPESB e intitulado “Núcleo de pesquisas em Química
Analítica da Bahia: Química e qualidade em alimentos”. / In this paper, it is proposed the synthesis of a new reagent derivative of
thiazole, 5-bromothiazolylazo-2-orcinol (Br-TAO) and its application in systems
for preconcentration of metals. The reagent was synthesized by diazotization
and coupling reactions. Then the solid product was purified by recrystallization
with ethanol and characterized. The reagent Br-TAO was employed in a
preconcentration procedure for cobalt using microdispersive liquid-liquid
extraction and determination by flame atomic absorption spectrometry (FAAS).
The enrichment factor and the limit of detection were 16 and 0.9 µg L-1,
respectively. The accuracy was tested by analysis of certified reference material
NIST 1570a, Spinach Leaves. The procedure was applied to the determination
of cobalt in water from Rio de Contas, located in Jequié-BA. Another procedure
employed the reagent Br-TAO in an on-line system with sequential injection and
cloud point extraction for preconcentration and determination of manganese by
FAAS. The procedure is based on the cloud point extraction of manganese in
the sequential injection system and retention in a minicolumn, with subsequent
elution and detection. Chemical and flow variables that affect the system were
optimized and some specific analytical and some analytical parameters were
determined, such as analytical frequency (48 h-1), enrichment factor (14), rate of
consumption (0.20 mL) and the limit of detection (0.5 µg L-1). The certified
reference materials NIST 1568a, Rice Flour and NIST 1573a, tomato leaves
were used to test the accuracy of the procedure. The method was applied to the
determination of manganese in rice flour, milk and corn. This work is part of a
PRONEX project, funded by CNPq / FAPESB entitled "Center for Research in
Analytical Chemistry of Bahia: Chemistry and quality food."
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Antiandrogênios em efluente hospitalar: extração com barras poliméricas, quantificação, identificação de metabólitos e subprodutos, proposição de rotas de degradação por processos avançados de oxidação / Antiandrogens in hospital effluent: extraction with polymer bars, quantification, identification of metabolites and subproducts and proposition of degradation routes by advanced oxidation processesBrenner, Carla Geane Brandenburg 12 April 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In this work, methods were developed for the determination of antiandrogens in hospital
effluent using the analytical technique HPLC-DAD. Microextraction techniques of
Spironolactone, Flutamide, Cyproterone and Tamoxifen were investigated: liquid-liquid
(LLME) and sorptive extraction (SBSE). For quantification of the analytes in hospital effluent
was used solid phase extraction (SPE) with recoveries of 75.0 to 109.0±1.0 to 13.0% in
aqueous solution and from 72.0 to 106.0±2.0 to 13.0% in hospital effluent. The average
concentrations of analytes in the effluent of emergency (PA) ranged from 0.00 to 11.70 μg L-1
(RSD 0.00 to 11.5%) and of general-HUSM 0.00 to 11.30 μg L-1 (0.00 to 6.78% RSD),
respectively. LC-ESI-MS/MS technique was used for fragmentation of the precursor ions, to
identify product ions, and for neutral mass loss. LC-ESI-QqLIT-MS/MS was used to identify
metabolites and subproducts. STR photoreactor of 800 mL was used for simple photolysis and
heterogeneous photocatalysis, and for ozonation, column reactor of 800 mL. Fractional
factorial design was applied to the extraction experiments, as well as, to AOPs. UV-radiation
was generated by mercury vapor lamp of 125 W and 401 W m-2. Polymer bars of
polydimethylsiloxane and polyurethane with TiO2 supported were developed for
photocatalysis. Kinetic studies of the degradation reactions were made, subproducts were
identified and fragmentation routes proposed. Metabolites were identified in hospital effluent.
Preliminary risk analysis revealed that spironolactone has lower environmental risk, and that
all analytes except tamoxifen, show PEC value > 0.01 μg L-1. / Neste trabalho foram desenvolvidos métodos para a determinação de antiandrogênios em
efluente hospitalar utilizando-se a técnica analítica de HPLC-DAD. Técnicas de
microextração de Espironolactona, Flutamida, Ciproterona e Tamoxifeno foram investigadas:
líquido-líquido (LLME) e extração sortiva (SBSE). Para a quantificação dos analitos em
efluente hospitalar foi usada extração em fase sólida (SPE) com recuperações de 75,0-
109,0±1,0-13,0%, em solução aquosa, e de 72,0-106,0±2,0-13,0%, em efluente hospitalar. As
concentrações médias dos analitos no efluente do pronto atendimento (PA) e geral-HUSM
variaram de 0,00-11,70 μg L-1 (RSD 0,00-11,5%) e 0,00-11,30 μg L-1 (RSD 0,00-6,78%),
respectivamente. A técnica de LC-ESI-MS/MS foi utilizada na fragmentação dos íons
precursores, na identificação dos íons-produto e perda de massa neutra. LC-ESI-QqLITMS/
MS foi usada na identificação de metabólitos e no estudo dos subprodutos. Fotorreator
STR de 800 mL foi usado para fotólise simples e fotocatálise heterogênea e, para ozonização,
reator tipo coluna de 800 mL. Planejamento fatorial fracionado foi aplicado nos experimentos
de extração, bem como, de PAOs. Radiação UV foi gerada com lâmpada de vapor de
mercúrio de 125 W e 401 W m-2. Barras poliméricas de polidimetilsiloxano e poliuretano com
TiO2 suportado foram desenvolvidas para a fotocatálise. Estudos cinéticos das reações de
degradação foram feitos, subprodutos foram identificados e rotas de fragmentação propostas.
Metabólitos foram identificados no efluente hospitalar. Análise preliminar de risco revelou
que a espironolactona apresenta menor risco ambiental e que todos os analitos, exceto
tamoxifeno, apresentam valor de PEC > 0,01 μg L-1.
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Isoflurano : desenvolvimento de um método analítico empregando microextração em fase sólida, incorporação em nanoemulsões e avaliação biológica das nanoemulsõesKrahn, Carolina Lopes January 2010 (has links)
O objetivo do presente trabalho foi desenvolver e validar um método analítico empregando microextração em fase sólida (SPME) para detecção e quantificação de isoflurano (ISO) na forma volátil e incluso em nanoemulsões intravenosas e, ainda, avaliar o efeito biológico destas. A detecção do ISO foi realizada através de cromatografia em fase gasosa com detector de ionização de chama (CG/DIC). As condições ideais para realização da pré-concentração e extração de ISO através da técnica de SPME foram temperatura ambiente, agitação constante, 30 min de extração e 2 min de dessorção no injetor do CG. O método desenvolvido foi validado avaliando os parâmetros de especificidade, linearidade, limites de detecção e quantificação, precisão, exatidão e robustez. As nanoemulsões contendo ISO foram desenvolvidas através da homogeneização à alta pressão, e apresentaram diâmetro médio, índice de polidispersão, potencial zeta e pH de 150 ± 0,78 nm, 0,08 ± 0,01, - 18 ± 2,4 mV e 6,03 ± 0,04, respectivamente. O pH foi ajustado para 7,4 (valor fisiológico). O teor de ISO nas formulações foi de 98,4 %. Não houve modificação das características físico-químicas das nanoemulsões após 30 dias de armazenamento a 8 ºC. Análises de espalhamento de luz múltiplo não demonstraram tendência a fenômenos de instabilidade física para as formulações. Os estudos do efeito anestésico das nanoemulsões intravenosas contendo ISO em cães evidenciaram uma redução significativa (p < 0,05) na dose comparada com a administração de ISO volátil. Não houve alterações no débito cardíaco, saturação de oxigênio na hemoglobina e nos biomarcadores das funções renal, hepática e muscular. Uma queda na pressão arterial dos cães foi observada em todos os tratamentos devido ao efeito hipotensor do ISO. Após administração das nanoemulsões contendo ISO e branca, observou-se taquipnéia, edema, eritema, e baixas concentrações de dióxido de carbono expiradas. Assim, a nanoemulsificação do ISO foi realizada com sucesso e a aplicação na anestesia geral intravenosa foi demonstrada. / The aims of this work were to develop and validate an analytical method using solidphase microextraction (SPME) to detect and quantify isoflurane (ISO) inhalation liquid and loaded in intravenous nanoemulsions, and also evaluate the biological effect of the formulations. ISO detection was made by gas chromatography with flame ionization detector (GC/FID). The ideal conditions setting for the pre concentration and extraction of ISO through SPME were environmental temperature, constant stirring, 30 min for extraction and 2 min for analyte desorption in the GC inlet port. The developed method was validated by means of specificity, linearity, detection and quantification limits, precision, accuracy and robustness. The ISOloaded nanoemulsions were formulated by high-pressure homogenization, and presented average diameter, polydispersity index, zeta potential and pH of 150 ± 0.78 nm, 0.08 ± 0.01, -18 ± 2.4 mV and 6.03 ± 0.04, respectively. The pH was adjusted to 7.4 (physiological value). The drug content on the formulations was 98.4 %. After 30 days of storage at 8 ºC no changes on nanoemulsion’s physicalchemical characteristics were observed. Multiple light scattering analysis did not demonstrate any physical destabilization phenomena for the formulations. The anesthetic effect study for the intravenous ISO-loaded nanoemulsions in dogs highlighted a significant reduction (p < 0.05) in dosage regimen when compared to the volatile ISO administration. There were no alterations on cardiac rate, oxygen hemoglobin saturation and on biomarkers of the renal, hepatic and muscle functionalities. A decrease in dog’s arterial blood pressure in all treatments due the hypotensive effect caused by ISO was observed. After the administration of the nanomulsions, ISO-loaded and unloaded, occurred tachypnea, edema, erythema and low end tidal concentrations of carbon dioxide. Taking all above into account, the method was considered easy on execution and suitable for laboratory routines, the ISO nanoemulsification was made successfully and its application on general anesthesia was demonstrated.
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