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Resin acids in commercial products and the work environment of Swedish wood pellets production : Analytical methodology, occurrence and exposureAxelsson, Sara January 2012 (has links)
The aims of the work this thesis is based upon were to develop convenient analytical procedures for determining resin acids in biological and environmental matrices, and apply them to enhance understanding of the occurrence, exposure to and uptake by exposed individuals of resin acids. Particular focus has been on the workplace environment of the Swedish wood pellets industry. Sample extraction procedures and high-performance liquid chromatography/electrospray ionisation-mass spectrometry (HPLC/ESI-MS) methodologies were developed for measuring resin acids in dust, skin and urine samples. Chromatographic separation of abietic (AA) and pimaric acid was achieved by using a polar-embedded C12 stationary phase. The HPLC/ESI-MS method avoids undesirable oxidation of AA, which was found to occur during the derivatisation step in the standard MDHS 83/2 gas chromatography/flame ionisation detection (GC/FID) methodology, leading to false observations of both AA and the oxidation product 7-oxodehydroabietic acid (7-OXO). Personal exposures to resin acids in the Swedish wood pellet production industry were found to be lower, on average, than the British Occupational Exposure Limit for rosin (50 µg/m3). The oxidised resin acid 7-OXO, was detected in both dust and skin samples indicating the presence of allergenic resin acids. A correlation between air and post-shift urinary concentrations of dehydroabietic acid (DHAA), and a trend towards an increase in urinary 7-OXO during work shifts, were also observed. Whether the increase in 7-OXO was due to direct uptake or metabolism of other resin acids cannot be concluded from the results. An efficient HPLC/UV methodology with diode-array detection was developed for screening commercial products for rosin that could be used in laboratories lacking mass spectrometers. Very high concentrations of free resin acids were detected in depilatory wax strips using the method. / At the time of doctoral defense, the following paper was unpublished and had a status as follows: Paper 4: Submitted.
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DESENVOLVIMENTO DE UM SIMPLES E NOVO SENSOR PARA FLUTAMIDA À BASE DE NANOTUBOS DE CARBONO OXIDADO E ÓXIDO DE GRAFENO: APLICAÇÃO EM AMOSTRAS DE URINA ARTIFICIAL E FORMULAÇÕES FARMACÊUTICAS / DEVELOPMENT OF A NEW AND SIMPLE SENSOR FOR FLUTAMIDE TO BASE OXIDIZED CARBON NANOTUBES AND GRAPHENE OXIDE: APPLICATION IN ARTIFICIAL URINE SAMPLES AND PHARMACEUTICAL FORMULATIONSFARIAS, Julianna Santos 06 March 2017 (has links)
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Previous issue date: 2017-03-06 / CAPES, FAPEMA,CNPQ / This paper describes the development of a simple and new sensor
electrochemical determination of flutamide in voltamétrica formulations
pharmaceutical and artificial urine specimens using a carbon electrode
vitreous (ECV) modified with oxidized carbon nanotubes and graphene oxide
(NCO-OG), which was named ECV/NCO-OG. Electronic microscopy techniques
scanning (SEM) and Raman Spectroscopy were used for the
characterization of carbon based materials. The electrochemical response of the analyte
front of the ECV/NCO-OG was investigated by cyclic voltammetry techniques
(VC) and square wave voltammetry (VOQ). The sensor exhibited a high activity
eletrocatalítica for the reduction of flutamide in 0.05 V vs. Ag/AgCl. The parameters
experimental influence the response of the electrode was investigated and the
optimum conditions were found for the electrode modified with NCO-OG, in
Britton-Robinson buffer solution-BR on concentration of 0.1 mol L-1 (pH 5). The
proposed sensor presented a wide range of linear response of concentration
for the flutamide of 0.1 to 1000 µmol L-1 (or µ g L-1 27.6 to 0.27 g L-1) for n = 15
(R2 = 0.997), limit of detection (LOD), limit of quantification (LOQ), and
sensitivity of 0.03 µmol L-1, 0.1 µmol L-1, and 0.30 µmol µA -1 L, respectively. The
ECV/NCO-OG was successfully applied to the determination of flutamide in
pharmaceutical formulations used in the treatment of prostate cancer and
artificial urine samples. The results obtained with the proposed sensor were
compared with the method described in the literature and showed a level of
95% confidence, demonstrating that there is no statistical difference between the method of
reference and the method proposed. The addition and recovery studies show that the
proposed method presents a satisfactory accuracy with average value of
101% recovery ( 1)%. for the fortified samples. / Este trabalho descreve o desenvolvimento de um simples e novo sensor
eletroquímico para determinação voltamétrica de flutamida em formulações
farmacêuticas e amostras de urina artificial empregando um eletrodo de carbono
vítreo (ECV) modificado com nanotubos de carbono oxidado e óxido de grafeno
(NCO-OG), o qual foi denominado ECV/NCO-OG. As técnicas microscopia eletrônica
de varredura (MEV) e a Espectroscopia Raman foram utilizadas para a
caracterização dos materiais à base de carbono. A resposta eletroquímica do analito
frente ao ECV/NCO-OG foi investigada através das técnicas de voltametria cíclica
(VC) e voltametria de onda quadrada (VOQ). O sensor exibiu uma alta atividade
eletrocatalítica para a redução da flutamida em 0,05 V vs Ag/AgCl. Os parâmetros
experimentais que influenciam a resposta do eletrodo foram investigados e as
condições ótimas foram encontradas para o eletrodo modificado com NCO-OG, em
solução tampão Britton-Robinson-BR na concentração de 0,1 mol L-1 (pH 5). O
sensor proposto apresentou uma ampla faixa de resposta linear de concentração
para a flutamida de 0,1 a 1000 µmol L-1 (ou 27,6 µg L-1 a 0,27 g L-1) para n=15
(R2=0,997), com limite de detecção (LOD), limite de quantificação (LOQ), e
sensibilidade de 0,03 µmol L-1, 0,1 µmol L-1, e 0,30 µA µmol-1 L, respectivamente. O
ECV/NCO-OG foi aplicado com sucesso para a determinação de flutamida em
formulações farmacêuticas utilizadas no tratamento de câncer de próstata e
amostras de urina artificial. Os resultados obtidos com o sensor proposto foram
comparados com o método descrito na literatura e observou-se um nível de
confiança de 95%, demonstrando que não há diferença estatística entre o método de
referência e o método proposto. Os estudos de adição e recuperação mostram que o
método proposto apresenta uma exatidão satisfatória com valor médio de
recuperação de 101% ( 1) %. para as amostras fortificadas.
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Vývoj UHPLC-MS/MS screeningové metody pro analýzu benzodiazepinů ve vzorcích moči / Development of UHPLC-MS/MS screening method for the determination of benzodiazepines in urine samplesHavelková, Lucie January 2018 (has links)
The aim of this diploma thesis was the development of a screening method for analysis of 17 benzodiazepines in urine samples using ultra high-performance liquid chromatography with tandem mass spectrometric detection. The partial task was to optimize the conditions for the enzymatic hydrolysis of benzodiazepine glucuronides present in urine using design of experiments (DOE). The optimized chromatographic system consisted of a Zorbax Eclipse Plus Phenyl-Hexyl RRHD column (100 × 2.1 mm, 1.8 μm) and mobile phase consisting of water with 0.1 % acetic acid (component A) and acetonitrile with 0.1 % acetic acid (component B) in various ratios according to the gradient program. Flow rate was 0.2 ml/min, column temperature was 40 řC, and total analysis time was 12 min. Calibration curves for all analytes were measured under optimized conditions in methanol and urine. After optimal detection conditions for oxazepam-glucuronide were found, oxazepam glucuronide was hydrolysed using β-glucuronidase from the abalone to confirm the functionality of the enzyme within the pilot experiment. Optimization of enzymatic hydrolysis conditions via 27 experiments proposed by program Minitab 16 using the Box-Behnken design will be realized later.
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