Realizaram-se estudos potenciométricos, em combinação com medições espectrofotométricas, para caracterizar a espécie de íon manganês obtida a partir de oxidação coulométrica a corrente constante utilizando-se solução de Mn(II) (0,050 mol.L-1) em N3- (0,50 a 2,0 mol.L-1) e H+ (0,01 mol.L-1). Graficamente foi possível concluir que a espécie gerada é Mn(III) e obter os valores dos potenciais condicionais de redução, E0\'x, do par Mn(III)/Mn(II), em soluções tampão N3-/HN3, de concentração de N3- 0,50; 1,0; 1,5; 2,0 e 4,0 mol.L-1 e H+ 0,010 mol.L-1, sendo 0,468, 0,421, 0,396, 0,377 e 0,336 V (vs. ECS), respectivamente. Esses valores de E0\'x permitiram o cálculo das constantes de equilíbrio para os complexos no sistema Mn(III)/N3-, sendo: β1 = 1,23.105 M-1, β2 = 6,03.108 M-2, β3 = 2,37.1011 M-3, β4 = 1,54.1011 M-4 e β5 = 9,57.1011 M-5 (T = 25,0 ± 0,1 ºC, I = 2,0 mol.L-1 com NaClO4). Os valores calculados para as absortividades molares, em 430 nm, para as espécies [Mn(N3)3], [Mn(N3)4]- e [Mn(N3)5]2- foram 226, 3.680 e 6560 mol-1.L.cm-1, respectivamente. Para o estudo do cátion Co(II), foram efetuadas oxidações coulométricas da mesma forma e nas mesmas condições que para o cátion Mn(II). Os valores de E0\'x encontrados para o par Co(III)/Co(II) foram 0,400, 0,338, 0,302, 0,277 e 0,228 V (vs. ECS), para as concentrações de N3- 0,50; 1,0; 1,5; 2,0 e 4,0 mol.L-1 e H+ 0,010 mol.L-1. Com os valores de E0\'x obtidos para os pares Co(III)/Co(II) e Mn(III)/Mn(II), calcularam-se as constante de equilíbrio global, K, para a reação redox entre [Co(N3)n]3-n e [Mn(N3)n]2-n, encontrando-se os valores 7,1xl0-2, 4,0x10-2, 2,6x10-2, 2,0x10-2 e l,5x10-2, para os tampões acima descritos, respectivamente. Outros estudos revelaram a possível formação da espécies Mn(VI) quando KMnO4 e K2MnO4 são adicionados, separadamente, a uma solução tampão azoteto, por exemplo, N3- = 1,5 mol.L-1 e HN3 = 0,05 mol.L-1. / Spectrophotometric studies combined with coulometric generation of Mn(III), in presence of large excess of Mn(II), showed a maximum absorbance peak at 430 nm. The average molar absorptivity increases with azide concentration (0.44 to 3.9 mol.L-1) from 3,100 to 6,300 mol-1.L.cm-1, showing a stepwise complex formation. Potential measurements of the Mn(III)/Mn(II) system in several azide aqueous buffers solutions: 1.0x10-2 mol.L-1 HN3, (0.50 to 2.0 mol.L-1) N3- and 5.0x10-1 mol.L-1 Mn(II) and constant ionic strength 2.0 mol.L-1, kept with sodium perchlorate, leads to the conditional potential, E0\'x, in several azide concentrations at 25.0 ± 0.1 ºC (0.468, 0.421, 0.396, 0.377 e 0.336 V (vs. SCE) for the 0.50; 1.0; 1.5; 2.0 and 4.0 mol.L-1 N3- concentration, respectively). Considering the overall formation constants of Mn(II)/N3-, from former studies, and the potential, E0\'s = 1.063 V vs. SCE, for Mn(III)/Mn(II) system in non-complexing medium, it was possible to calculate the Fronaeus function, F0(L), and the following overall formation constants: β1 = 1.2x105 M-1, β2 = 6.0x108 M-2, β3 = (2.4±0.7)x1011 M-3, β4 = (1.5±0.5)x1011 M-4 and β5 = (9.6±.0.8)x1011 M-5 for the Mn(III)/N3- complexes. The molar absorptivity values, at 430 nm, found for the species [Mn(N3)3], [Mn(N3)4]- and [Mn(N3)5]2- were 226, 3,680 and 6,560 mol-1.L.cm-1, respectively. Similar studies with Co(II) in the same conditions, lead to the following conditional potentials, E0\'x, for the Co(III)/Co(II) system: 0.400, 0.338, 0.302, 0.277 e 0.228 V (vs. SCE). Using the E0\'x values obtained for both systems, Co(III)/Co(II) and Mn(III)/Mn(II), it was possible to calculate the equilibrium constant for the redox reaction between [Co(N3)n]3-n and [Mn(N3)n]2-n. The values found were 7.1xl0-2, 4.0x10-2, 2.6x10-2, 2.0x10-2 and 1.5x10-2, for 0.50; 1.0; 1.5; 2.0 and 4.0 mol.L-1 N3- concentration, respectively, in the same acidity (1.0x10-2 mol.L-1 HN3).

Orientador: Adriana Vitorino Rossi / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-20T21:18:58Z (GMT). No. of bitstreams: 1 Souza_PatriciaTononde_M.pdf: 1500158 bytes, checksum: 99c73fcb4e4c8143227e13cef0571323 (MD5) Previous issue date: 2012 / Resumo: Capsaicinóides (CAPS) são substâncias responsáveis pela pungência em pimentas do gênero Capsicum. Quantificar CAPS é relevante devido às aplicações desses compostos na indústria alimentícia, farmacêutica e cosmética, além do uso em armas químicas. Nesse trabalho, foi desenvolvido método espectrofotométrico baseado na reação colorimétrica entre CAPS, Co e 4-(2-piridilazo)resorcinol, PAR, para quantificação de CAPS totais (CCAPS) em diversas espécies de Capsicum. O produto da reação tem proporção estequiométrica Co:PAR:CAPS 1:2:2 e absorção em 510 nm proporcional a CCAPS. A curva analítica apresentou faixa linear entre 0,001 e 0,03 U, limite de detecção = 0,0004 U e limite de quantificação = 0,0005 U (U = mg CAPS/g pimenta) e coeficiente de correlação = 0,9979. Os resultados foram comparados com o método de cromatografia líquida de alta eficiência (HPLC) e não apresentaram diferença significativa com 95% de confiança, além disso, ambos resultados são coerentes com as escalas organolépticas disponíveis na literatura. No aperfeiçoamento das condições para obtenção de extratos etanólicos de CAPS, estabeleceu-se o uso de cachaça (teor alcoólico 39%), proporção pimenta:cachaça 30:50 g/mL e agitação de 30 min. O estudo da conservação dos extratos indicou que é favorável armazená-los a 6°C, a estocagem das pimentas in natura a -11 °C por até três meses não leva a perda significativa de CAPS e a CCAPS aumenta a medida que o estágio de maturação de pimenta é completado / Abstract: Capsaicinoids (CAPS) are substances responsible for pungency in Capsicum. CAPS is relevant to quantify due to the applications of these comounds in food, pharmaceutical and cosmetic industries, and the use of chemical weapons. Inthis work, we developed a spectrophotometric method based on the colorimetric reaction between CAPS, Co and 4-(2-pyridylazo)resorcinol, PAR, for quantification of total CAPS (CCAPS) in several species of Capsicum. The product of the reaction is stoichiometric Co:PAR:CAPS 1:2:2 and absorption at 510 nm proportional to CCAPS. The analytical curve linear range between 0,001 and 0,03 U, detection limit = 0,0004 and limit of quantification U = 0,0005 U (U = mg CAPS/g pepper) and correlation coefficient = 0,9979. The results were compared with the method of high performance liquid chromatography (HPLC) and not significantly different at 95% confidence, moreover, both results are consistent with the organoleptic scales available in the literature. The improvement of conditions for obtaining ethanol extracts of CAPS, established the use of cachaça (alcohol content 39%), proportion pepper:cachaça 30:50 g/mL and stirred for 30 min. The study of the conservation of the extracts indicated that it supports storing them at 6 °C, the storage of in nature peppers at -11 °C for up to three months does not lead to significant loss of CAPS and CCAPS increases as the stage of maturation of pepper is added / Mestrado / Quimica Analitica / Mestra em Química

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<p>The paper and the graphics industries use two instruments with different optical geometry (d/0 and 45/0) to measure the quality of paper prints. The instruments have been reported to yield incompatible measurements and even rank samples differently in some cases, causing communication problems between these sectors of industry.A preliminary investigation concluded that the inter-instrument difference could be significantly influenced by external factors (background, calibration, heterogeneity of the medium). A simple methodology for eliminating these external factors and thereby minimizing the instrument differences has been derived. The measurements showed that, when the external factors are eliminated, and there is no fluorescence or gloss influence, the inter-instrument difference becomes small, depends on the instrument geometry, and varies systematically with the scattering, absorption, and transmittance properties of the sample.A detailed description of the impact of the geometry on the results has been presented regarding a large sample range. Simulations with the radiative transfer model DORT2002 showed that the instruments measurements follow the physical radiative transfer model except in cases of samples with extreme properties. The conclusion is that the physical explanation of the geometrical inter-instrument differences is based on the different degree of light permeation from the two geometries, which eventually results in a different degree of influence from near-surface bulk scattering. It was also shown that the d/0 instrument fulfils the assumptions of a diffuse field of reflected light from the medium only for samples that resemble the perfect diffuser but it yields an anisotropic field of reflected light when there is significant absorption or transmittance. In the latter case, the 45/0 proves to be less anisotropic than the d/0.In the process, the computational performance of the DORT2002 has been significantly improved. After the modification of the DORT2002 in order to include the 45/0 geometry, the Gauss-Newton optimization algorithm for the solution of the inverse problem was qualified as the most appropriate one, after testing different optimization methods for performance, stability and accuracy. Finally, a new homotopic initial-value algorithm for routine tasks (spectral calculations) was introduced, which resulted in a further three-fold speedup of the whole algorithm.The paper and the graphics industries use two instruments with different optical geometry (d/0 and 45/0) to measure the quality of paper prints. The instruments have been reported to yield incompatible measurements and even rank samples differently in some cases, causing communication problems between these sectors of industry.A preliminary investigation concluded that the inter-instrument difference could be significantly influenced by external factors (background, calibration, heterogeneity of the medium). A simple methodology for eliminating these external factors and thereby minimizing the instrument differences has been derived. The measurements showed that, when the external factors are eliminated, and there is no fluorescence or gloss influence, the inter-instrument difference becomes small, depends on the instrument geometry, and varies systematically with the scattering, absorption, and transmittance properties of the sample.A detailed description of the impact of the geometry on the results has been presented regarding a large sample range. Simulations with the radiative transfer model DORT2002 showed that the instruments measurements follow the physical radiative transfer model except in cases of samples with extreme properties. The conclusion is that the physical explanation of the geometrical inter-instrument differences is based on the different degree of light permeation from the two geometries, which eventually results in a different degree of influence from near-surface bulk scattering. It was also shown that the d/0 instrument fulfils the assumptions of a diffuse field of reflected light from the medium only for samples that resemble the perfect diffuser but it yields an anisotropic field of reflected light when there is significant absorption or transmittance. In the latter case, the 45/0 proves to be less anisotropic than the d/0.In the process, the computational performance of the DORT2002 has been significantly improved. After the modification of the DORT2002 in order to include the 45/0 geometry, the Gauss-Newton optimization algorithm for the solution of the inverse problem was qualified as the most appropriate one, after testing different optimization methods for performance, stability and accuracy. Finally, a new homotopic initial-value algorithm for routine tasks (spectral calculations) was introduced, which resulted in a further three-fold speedup of the whole algorithm.</p> / QC 20100707 / PaperOpt, Paper Optics and Colour

O objetivo deste estudo foi avaliar a estabilidade de cor de três marcas comerciais de porcelanas aluminizadas durante seu processo de queima. Para o experimento foram confeccionados 30 corpos de prova em forma de disco com 2mm de espessura e 10mm de circunferência, sendo 10 da marca ALLCeram, 10 da marca Noritake Cerabien CZR e 10 da marca Vita VM7. As amostras foram queimadas 10 vezes. As leituras de cor foram feitas em espectrofotômetro de reflexão nos seguintes intervalos: após a 1ª queima, após a 3ª queima, após a 5ª queima e após a 10ª queima. As curvas de reflexão foram convertidas em valores LAB e a diferença de cor foi medida através do método CIELAB (FE). Os resultados obtidos demonstraram que existe variação de cor e que esta variação depende do número de queimas realizadas e da marca comercial utilizada. / The purpose of this investigation was to quantify in CIE FE units the differences in color produced by multiple firing of three allceramic systems. For this study 30 samples were fabricated of 3 brands: AllCeram, Noritake Cerabien CZR and Vita VM7. A spectrophotometer was used for reflectance measurement of color after 1 firing, 3 firings, 5 firings and 10 firings. The results were converted in CIELAB units. Color differences, FE, were calculated in the CIE color space. Color differences as a result of multiple firings depended on the number of firings and the brand tested.

Abstract Introduction This study evaluated the effect of the polymer polyvinylalcohol-carbazate (PVAC) on the bacteria Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa. PVAC is a polymer with a carbazate moiety that neutralizes free aldehydes and has shown great promise in stabilizing erythrocytes during long term storage. It has also been shown to reduce intraperitoneal adhesions after trauma. For this study, two Gram positive and two Gram negative bacteria strains were used with PVAC to evaluate its effect. Materials and methods PVAC was obtained from the research team at Ångström Laboratory, Uppsala. The bacteria were obtained from Clinical Microbiology and Hospital Hygiene, Academic Hospital, Uppsala. The methods used were spectrophotometric assessment of bacteria growth, use of FITC-conjugated PVAC to study adherence to bacteria, use of FITC-antibodies to study PVAC’s effect on bacterial adherence to erythrocytes and a qPCR for quantification of E. coli. Results and discussion PVAC displayed a clear effect of inhibition of bacteria growth in the study as shown by use of spectrophotometric assessment. Trials with FITC-PVAC showed that the polymer adheres directly to the bacteria, displaying a possible function of its inhibitory properties. The qPCR assay was able to detect the bacteria in all the dilutions used. Introduction This study evaluated the effect of the polymer polyvinylalcohol-carbazate (PVAC) on the bacteria Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa. PVAC is a polymer with a carbazate moiety that neutralizes free aldehydes and has shown great promise in stabilizing erythrocytes during long term storage. It has also been shown to reduce intraperitoneal adhesions after trauma. For this study, two Gram positive and two Gram negative bacteria strains were used with PVAC to evaluate its effect. Materials and methods PVAC was obtained from the research team at Ångström Laboratory, Uppsala. The bacteria were obtained from Clinical Microbiology and Hospital Hygiene, Academic Hospital, Uppsala. The methods used were spectrophotometric assessment of bacteria growth, use of FITC-conjugated PVAC to study adherence to bacteria, use of FITC-antibodies to study PVAC’s effect on bacterial adherence to erythrocytes and a qPCR for quantification of E. coli. Results and discussion PVAC displayed a clear effect of inhibition of bacteria growth in the study as shown by use of spectrophotometric assessment. Trials with FITC-PVAC showed that the polymer adheres directly to the bacteria, displaying a possible function of its inhibitory properties. The qPCR assay was able to detect the bacteria in all the dilutions used.

Para quantificar o teor de lignina em alguns cultivares de aveia, foi utilizado o método espectrofotométrico "lignina solúvel em brometo de acetila – LSBA", onde a lignina é solubilizada em uma solução a 25% de brometo de acetila em ácido acético glacial e em seguida sua absorbância lida a 280 nm; como padrão de referência foi utilizada a lignina extraída da aveia através de uma solução ácida de dioxana. A quantificação da lignina foi realizada em oito cultivares de aveia, nas frações planta inteira, caule e folha, em três estádios de maturidade (45, 55 e 65 dias de idade). Os resultados obtidos foram comparados com três métodos gravimétricos: lignina detergente ácido (LDA), lignina permanganato de potássio (LPer) e lignina Klason (LK). Os quatro métodos estudados mostraram teores de lignina diferentes entre si. Os resultados de LSBA foram superiores para quase todos os cultivares, ocorrendo o inverso para a LDA. Houve uma pequena diferença em relação aos dias de corte, com dados superiores para LSBA, onde o caule apresentou maior variação em relação às demais frações. As curvas de regressão e os espectrogramas indicaram presença de diferenças qualitativas entre as ligninas provenientes da aveia forrageira nos diferentes estádios de maturidade. / To quantify lignin content in some varieties of oat, it was employed the spectrophotometric method acetyl bromide soluble lignin – ABSL where lignin is dissolved into a 25% acetyl bromide solution in glacial acetic acid and its absorbance read at 280 nm; as a standard it was employed a, lignin extracted by mild acidic dioxane solution from the same sample. Lignin quantification was evaluated in eight oat cultivars, divided in three vegetable parts (whole plant, stem and leaf), and three different maturity stages (cuts at 45, 55 and 65 days). Obtained results were compared with three gravimetric methods: acid detergent lignin (ADL), potassium permanganate lignin (PerL) and Klason lignin (KL). All four methodologies yielded different results. Overall, ABSL yielded highest values whereas ADL yielded the lowest ones. There was a slight difference related to maturity, with higher values for ABSL, where stem fraction showed higher variation when comparing to the two other vegetable parts. Regression equations and espectrograms indicated the presence of qualitative differences between lignins from at distinct maturity stages.

Pirmą kartą Lietuvoje nustatytas bendras fenolkarboksirūgščių kiekis Achillea millefolium L. vaistinėje augalinėje žaliavoje. Taip pat pirmą kartą nustatytas populiacinis bei morfologinis kiekybinės rūgščių sudėties kintamumas Lietuvos natūraliose augavietėse augančių kraujažolių augaluose. Nustatytas bendras fenolkarboksirūgščių kiekis žolės 70 proc. etanoliniuose ekstraktuose vidutiniškai siekė 58,690±4,279 mg/g. Taip pat nustatyta, kad A. millefolium augalinėms žaliavoms būdingas ženklus fenolkarboksirūgščių sudėties rodiklių kintamumas, tiesiogiai priklausantis nuo augalo morfologinės dalies. Bendras fenolkarboksirūgščių kiekis žiedų žaliavose vidutiniškai siekė 58,029±3,492 mg/g. Lapų žaliavose vidutiniškai sukaupiama 102,150±7,50 mg/g, tai yra beveik du kartus daugiau nei žiedų ir žolės žaliavose, stiebuose - 22,722±2,928 mg/g. Nustatytas ženklus fenolkarboksirūgščių kiekinės sudėties įvairavimas tarp tirtų kraujažolių cenopopuliacijų. Vaistinės žaliavos bandinių grupėje bendras rūgščių kiekis skirtingose cenopopuliacijose kito nuo 33,490 iki 86,474 mg/g, žieduose - nuo 40,240 iki 73,022 mg/g, lapuose - nuo 74,110 iki 150,176 mg/g, stiebuose - nuo 15,605 iki 43,381 mg/g. Atlikus statistinę analizę norint palyginti tirtų bandinių grupių vidurkius, tirtose žaliavose nustatyta statistiškai reikšmingų skirtumų. Eksperimentinių duomenų sklaidai apibūdinti apskaičiuoti bandinių grupių variacijos koeficientai (žolės – 26,29 proc., žiedų – 19,03 proc., lapų – 23,25 proc... [toliau žr. visą tekstą] / For the first time ever in Lithuania, the general amount of phenolcarboxylic acids was measured in the raw plant material of Achillea millefolium L. medicinal plants. The population and morphological variance of the quantitative content of the acids in yarrow plants growing in the natural habitats of Lithuania was also determined for the first time. The overall amount of phenolcarboxylic acids was determined to be 58,690±4.279 mg/g in 70 percent ethanol extracts of the herb. It was also determined that significant variability exists in indicators of the phenolcarboxylic acid content of A. millefolium plants. This is directly dependent on the morphological part of the plant. The total average of the phenolcarboxylic acids content in flowers was 58,029±3,492 mg/g. The total average in leaves was 102,150±7,50 mg/g, almost two times higher the content found in the flowers and herbs. The average acids content accumulated in stems was 22,722 ± 2,928 mg/g. Determinated sign variability of the content of phenolcarboxylic acids in the investigated cenopopulations of yarrow. The total acids content of different cenopopulations in the raw plant materials of yarrow ranged from 33,490 to 86,474 mg/g, in flowers - from 40,240 to 73,022 mg /g, in leaves - from 74,110 to 150,176 mg/g, in stems - from 15,605 to 43,381 mg/g. Statistical comparison of sample group averages found statistically significant differences between sample group averages. The dispersion of the experimental data was... [to full text]

Made available in DSpace on 2014-06-11T19:35:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-09-20Bitstream added on 2014-06-13T21:07:15Z : No. of bitstreams: 1 gotardo_ma_dr_araiq.pdf: 948133 bytes, checksum: 414edaf8ae833739041194beb4696ec5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Este trabalho propõe métodos por espectroscopia de reflectância difusa utilizando spot test para determinação de furosemida, hidroclorotiazida, propranolol e atenolol em formulações farmacêuticas e também um método espectrofotométrico no visível para determinação de metildopa em formulações farmacêuticas. Os métodos reflectométricos foram baseados em reações em papel de filtro, utilizando p-dimetilaminocinamaldeído (PDAC) como reagente cromogênico para furosemida e hidroclorotiazida; 2,6- dicloroquinona-4-cloroimida (DCQ) para propranolol e p-cloranil para atenolol. Estas reações produziram compostos coloridos com máximo de AR (log 1/R) em 585 nm para furosemida e hidroclorotiazida; 500 nm para propranolol e 550 nm para atenolol. Planejamentos experimentais foram empregados no desenvolvimento de todos os métodos e, as condições otimizadas para as respectivas reações de spot test foram: 10 μL de solução de furosemida em acetona, 20 μL de HCl 6,3% (m/v) em metanol e 20 μL de PDAC 0,4% (m/v) em metanol, nesta ordem, com aquecimento a 80ºC por 5 minutos; 20 μL de solução de hidroclorotiazida em acetona, 20 μL de HCl 10% (m/v) em metanol e; 20 μL de PDAC 0,4% (m/v) em metanol, nesta ordem, com aquecimento a 80ºC por 8 minutos; 30 μL de solução de propranolol em etanol 35% (v/v) e 30 μL de solução de DCQ 70 mg/mL em acetona e; 20 μL de solução de atenolol em metanol e 20 μL de p-cloranil 8,00 × 10-2 mol L-1 em dioxano. As curvas analíticas foram lineares nas faixas de concentração de 7,56 × 10-3 – 6,05 × 10-2 mol L-1 (r=0,9987) para furosemida, 3,36 × 10-2 – 1,01 × 10-1 mol L-1 (r=0,9979) para hidroclorotiazida, 1,35 × 10-2 – 8,45 × 10-2 mol L-1 (r=0.9991) para propranolol e 1,13 × 10-2 – 7,88 × 10-2 mol L-1 (r=0,9992) para atenolol. O método espectrofotométrico para a determinação de metildopa em formulações... / This work proposes methods by diffuse reflectance spectroscopy using spot tests for the determination of furosemide, hydrochlorothiazide, propranolol and atenolol in pharmaceutical formulations and also a visible spectrophotometric method for the determination of methyldopa in pharmaceutical formulations. The reflectometric methods were based on spot test reactions on filter paper, using p-dimetylaminocinnamaldehyde (p-DAC) as chromogenic reagent for furosemide and hydrochlorothiazide, 2,6-dichloroquinone -4- chloroimide (DCQ) for propranolol and, p-chloranil for atenolol. These reactions produced colored compounds with maximum AR (log 1/R) at 585 nm for furosemida and hydrochlorothiazide; 500 nm for propranolol and 550 nm for atenolol. Experimental designs were employed in the development of all methods and, the conditions optimized for the respective spot test reactions were: 10 æL of furosemide solution in acetone, 20 æL of HCl 6.3% (w/v) in methanol and 20 æL of PDAC 0.4% (w/v) in methanol, in this order, with heating at 80ºC for 5 minutes; 20 æL of hydrochlorotiazide solution in acetone, 20 æL of HCl 10% (w/v) in methanol and 20 æL of p-DAC 0.4% (w/v) in methanol, in this order, with heating at 80ºC for 8 minutes; 30 æL of propranolol solution in ethanol 35% (v/v) and 30 æL of DCQ solution at 70 mg/mL in acetone and, 20 æL of atenolol solution in methanol and 20 æL of p-cloranil at 8.00 OE 10-2 mol L-1 in dioxane. The analytical curves were linear in the concentration ranges of 7.56 OE 10-3 - 6.05 OE 10-2 mol L-1 (r=0.9987) for furosemide, 3.36 OE 10-2 - 1.01 OE 10-1 mol L-1 (r=0.9979) for hydrochlorothiazide, 1.35 OE 10-2 - 8.45 OE 10-2 mol L-1 (r=0.9991) for propranolol and (r=0.9992) for atenolol. The spectrophotometric method for the determination of methyldopa in pharmaceutical formulations used p-chloranil as chromogenic reagent and H2O2 as accelerator of the reaction.

Orientador: Helena Redigolo Pezza / Banca: Massao Ionashiro / Banca: Matthieu Tubino / Banca: Fabio Rodrigo Piovezani Rocha / Banca: Ronaldo Censi Faria / Resumo: Este trabalho propõe métodos por espectroscopia de reflectância difusa utilizando spot test para determinação de furosemida, hidroclorotiazida, propranolol e atenolol em formulações farmacêuticas e também um método espectrofotométrico no visível para determinação de metildopa em formulações farmacêuticas. Os métodos reflectométricos foram baseados em reações em papel de filtro, utilizando p-dimetilaminocinamaldeído (PDAC) como reagente cromogênico para furosemida e hidroclorotiazida; 2,6- dicloroquinona-4-cloroimida (DCQ) para propranolol e p-cloranil para atenolol. Estas reações produziram compostos coloridos com máximo de AR (log 1/R) em 585 nm para furosemida e hidroclorotiazida; 500 nm para propranolol e 550 nm para atenolol. Planejamentos experimentais foram empregados no desenvolvimento de todos os métodos e, as condições otimizadas para as respectivas reações de spot test foram: 10 μL de solução de furosemida em acetona, 20 μL de HCl 6,3% (m/v) em metanol e 20 μL de PDAC 0,4% (m/v) em metanol, nesta ordem, com aquecimento a 80ºC por 5 minutos; 20 μL de solução de hidroclorotiazida em acetona, 20 μL de HCl 10% (m/v) em metanol e; 20 μL de PDAC 0,4% (m/v) em metanol, nesta ordem, com aquecimento a 80ºC por 8 minutos; 30 μL de solução de propranolol em etanol 35% (v/v) e 30 μL de solução de DCQ 70 mg/mL em acetona e; 20 μL de solução de atenolol em metanol e 20 μL de p-cloranil 8,00 × 10-2 mol L-1 em dioxano. As curvas analíticas foram lineares nas faixas de concentração de 7,56 × 10-3 - 6,05 × 10-2 mol L-1 (r=0,9987) para furosemida, 3,36 × 10-2 - 1,01 × 10-1 mol L-1 (r=0,9979) para hidroclorotiazida, 1,35 × 10-2 - 8,45 × 10-2 mol L-1 (r=0.9991) para propranolol e 1,13 × 10-2 - 7,88 × 10-2 mol L-1 (r=0,9992) para atenolol. O método espectrofotométrico para a determinação de metildopa em formulações...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work proposes methods by diffuse reflectance spectroscopy using spot tests for the determination of furosemide, hydrochlorothiazide, propranolol and atenolol in pharmaceutical formulations and also a visible spectrophotometric method for the determination of methyldopa in pharmaceutical formulations. The reflectometric methods were based on spot test reactions on filter paper, using p-dimetylaminocinnamaldehyde (p-DAC) as chromogenic reagent for furosemide and hydrochlorothiazide, 2,6-dichloroquinone -4- chloroimide (DCQ) for propranolol and, p-chloranil for atenolol. These reactions produced colored compounds with maximum AR (log 1/R) at 585 nm for furosemida and hydrochlorothiazide; 500 nm for propranolol and 550 nm for atenolol. Experimental designs were employed in the development of all methods and, the conditions optimized for the respective spot test reactions were: 10 æL of furosemide solution in acetone, 20 æL of HCl 6.3% (w/v) in methanol and 20 æL of PDAC 0.4% (w/v) in methanol, in this order, with heating at 80ºC for 5 minutes; 20 æL of hydrochlorotiazide solution in acetone, 20 æL of HCl 10% (w/v) in methanol and 20 æL of p-DAC 0.4% (w/v) in methanol, in this order, with heating at 80ºC for 8 minutes; 30 æL of propranolol solution in ethanol 35% (v/v) and 30 æL of DCQ solution at 70 mg/mL in acetone and, 20 æL of atenolol solution in methanol and 20 æL of p-cloranil at 8.00 OE 10-2 mol L-1 in dioxane. The analytical curves were linear in the concentration ranges of 7.56 OE 10-3 - 6.05 OE 10-2 mol L-1 (r=0.9987) for furosemide, 3.36 OE 10-2 - 1.01 OE 10-1 mol L-1 (r=0.9979) for hydrochlorothiazide, 1.35 OE 10-2 - 8.45 OE 10-2 mol L-1 (r=0.9991) for propranolol and (r=0.9992) for atenolol. The spectrophotometric method for the determination of methyldopa in pharmaceutical formulations used p-chloranil as chromogenic reagent and H2O2 as accelerator of the reaction. / Doutor