The effects of adding a biodegradable litter amendment (AmmoSoak), developed from steam exploded corncobs, to poultry litter prior to pyrolysis on the product yields and qualities were investigated. Mixtures of litter and AmmoSoak were pyrolyzed in a bench-scale fluidized bed reactor. The objective of the second phase was to start-up a pilot-scale fluidized bed reactor unit. The poultry litter had a lower higher heating value (HHV), higher moisture, ash, nitrogen, sulfur, and chlorine contents than AmmoSoak. Analysis of the poultry litter indicated a mixture of volatiles, hemicelluloses, cellulose, lignin, ash, and proteins. AmmoSoak had a simpler composition than the litter; mainly hemicelluloses, cellulose, and lignin. Bench-scale studies indicated that adding AmmoSoak affected the yields and characteristics of the products. Addition of Ammosoak increased the bio-oil and syngas yields and decreased char yields. Adding AmmoSoak to the feed decreased the pH, water contents, initial viscosity, and the rate at which the viscosity increased with time, while densities and HHVs increased. The addition of Ammosoak to poultry litter also increased the carbon and oxygen contents of the boi-oils while nitrogen, hydrogen, sulfur, chlorine and ash contents decreased. A pilot-scale fluidized bed reactor was designed, constructed, installed and investigated for the pyrolysis of poultry litter. Fluidization and thermal equilibrium of the reactor were successfully demonstrated. The reactor was heated by combustion of propane. To ensure complete combustion, the combustion water was collected and compared to the stoichiometric yield. Complete combustion was achieved. Bio-oil yields on the pilot scale were lower than those obtained on the bench-scale pyrolysis unit. The water soluble fractions of the bio-oils were rich in oxygen. Water insoluble fractions were rich in carbon and ash. / Master of Science

In view of the increasing global challenge of bacterial resistance, there exists an urgent need for the rationale development of antibacterial compounds with either novel or multiple mechanisms of action. Two chalcone-derivatives, F1 and F23, demonstrated MICs within the range of 16 to >512 μg/ml against two plant pathogens (P. caratovoram and C. michiganensis subsp. michiganensis) as well as important clinical bacterial species. Both compounds displayed an MIC of 32 μg/ml against quinolone-resistant S. aureus. Whilst possessing weak activities individually, each semi-synthetic agent displayed notable synergistic action with polymyxin B against S. aureus, C. violaceum, E. coli and Ps. aeruginosa, thereby recording FICs within the range of <0.093 to 2 that indicated the existence of synergism in some instance. These chalcone compounds applied with polymyxin B displayed a notable FICindex of <0.093 against the Neisseriaceae C. violaceum, and a potential noteworthy capacity to extend the spectrum of activity of the latter antibiotic to include Gram-positive S. aureus species. F1 inhibited staphylococcal replication in broth and the combination of either of both chalcone-derivatives with polymyxin B instituted a metabolic blockage in S. aureus and other bacterial species as determined through a modified MTT reduction assay. The combined agents inflicted major disruptions to the S. aureus cytoplasmic membrane bilayer as evidenced by the release of intracellular potassium as well as the influx of Sytox Green fluorescent stain. Notable levels of cell membrane potential dissipation, leakage of intracellular potassium ions and blockage of reducing enzymes activities occurred within the first 30 minutes, well in advance of significant loss in cell viability that was recorded usually after 4 – 8 hours, suggesting these activities were prerequisites to cell death. In erythrocyte lysis assay, the synergistic combinations of 128 μg/ml of either of both chalcone derivatives with 128 μg/ml polymyxin B displayed the lowest degree of haemolysis, followed by that occurring with 32 μg/ml of the chalcone-derivatives combined with 256 μg/ml of the polypeptide antibiotic. In conclusion, further structure activity modifications aimed at improving the aqueous solubility of these chalcone-derivatives as well as the antibacterial activity recorded for certain combination concentrations of polymyxin B with either of these semi-synthetic agents may be required before considerations are made for the possibility for potential external formulations. Such preparations may include antiseptic creams, lotions, ointments, as well as aerosols that can be applied with nebulizers in targeted delivery for such cases like cystic fibrosis.

This master's thesis discusses the use of UV/VIS spectrophotometry in chemistry teacher education. Optical methods principles are described in theoretical part of the thesis, and. the main part is dedicated to UV-VIS spectrophotometry. Tasks for quantifying and qualifying substances determination are described in experimental part. Educational tasks are described in a way so that chemistry teachers could use for instructions.

[pt] O ferro é extraído sob a forma de minério de ferro, sendo 99 por cento utilizado na indústria siderúrgica. Os documentos normativos existentes indicam a volumetria como à técnica analítica para quantificar o teor de ferro em minério de ferro, com exceção da ISO 9516-1: 2003, que, recomenda a espectrometria de fluorescência de raios-X por comprimento de onda (WDXRF). Na literatura são descritos estudos utilizando a espectrometria de fluorescência de raios-X por dispersão de energia (EDXRF) para quantificar ferro em minério de ferro, mas em nenhuma destas publicações é caracterizada a confiabilidade metrológica e a incerteza de medição, sendo outros aspectos importantes na seleção de um método analítico o impacto económico e tempo de análise. No presente trabalho realizou-se um estudo comparativo de impacto económico, tempo de análise e desempenho metrológico na quantificação de ferro em minério de ferro por meio da técnica de EDXRF, comparando-o com a espectrofotometria de absorção molecular e volumetria (titulação com dicromato de potássio), abrangendo a incerteza de medição e a avaliação de parâmetros de validação para EDXRF. A análise volumétrica foi realizado baseado nas normas ANBT NBR 8577:2011 e ASTM E246:2010. Na espectrofotometria de absorção molecular, adaptou-se o método da ortofenantrolina descrito na norma ABNT NBR 13934:1997. Nas outras técnicas precisam-se da abertura da amostra, na EDXRF, as amostras foram preparadas na forma de pastilha (pó de minério prensado). Os métodos avaliados apresentaram desempenhos metrológicos equivalentes, os melhores indicadores de custo e tempo em longo prazo foram observados para o método por EDXRF na quantificação do teor de ferro em minério. / [en] After its extraction in the form of iron ore, 99 per cent of the iron is employed in the steel industry. The normative documents existents recommend to volumetry as the technical analytic for quantification of iron in iron ore, with the exception of ISO 9516-1: 2003, which recommends the fluorescence spectrometry X-ray wavelength (WDXRF). In literature, there are studies using energy dispersive Xray fluorescence spectrometry (EDXRF) to quantify iron in iron ore, but none of these is characterized by complete validation and measurement uncertainty. Other aspects to be considered when selecting an analytical method are the financial cost and the time for analysis. In this work it is carried out a comparative study of financial cost, time analysis and metrological performance on quantification of iron ore through the EDXRF technique, in comparison with the results obtained by molecular absorption spectrophotometry and volumetry (titration with potassium dichromate), including measurement uncertainty evaluation and some parameter of validation for EDXRF. The molecular absorption spectrophotometry measurements were performed by colorimetric orthophenanthroline method. Unlike the other approaches that require sample preparation with acid, for EDXRF measurements, samples were prepared in tablet form (pressed iron ore powder). The evaluated methods presented equivalent metrological performances on determining iron in ore, but the best long-term outcome for cost was observed in the results obtained by EDXRF method.

Blodgassprutor beställs för att undersöka en patients syra-bas-status, laktatkoncentration och elektrolytkoncentration. Några orsaker till balansrubbningar kan vara trauma, syrebrist, infektion, intoxikation eller svält. År 2018 installerades ett nytt rörtransportsystem på Västerviks sjukhus och syftet med studien var att undersöka om det är möjligt att transportera blodgassprutor i det nya rörsystemet utan att provresultat påverkas. Analyser som studerades var pH (power of hydrogen), syretryck, koldioxidtryck, syrgasmättnad, natriumjoner, kaliumjoner, fria kalciumjoner, standardbikarbonat, basöverskott och laktat. Studien omfattade 27 arteriella dubbelprover där det ena provet transporterades i rörtransportsystemet och det andra transporterades manuellt till laboratoriet. Proverna analyserades på instrumentet ABL 800 Flex, inom 30 minuter efter provtagning, med analysmetoderna potentiometri, amperometri och spektrofotometri. Resultaten jämfördes i korrelationsdiagram med en regressionslinje för att påvisa samband mellan proverna. Korrelationsdiagrammen visade positiv linjär korrelation hos samtliga analyser och ett samband kunde påvisas (r = 0,930-0,998). Om resultatet från proverna som transporterats manuellt ökade, ökade även resultatet från proverna som transporterats i rörpost och tvärtom. Ett stapeldiagram skapades för att visualisera skillnader i medelvärde som visade en liten skillnad på basöverskott som ökade efter transport i rörpostsystemet. Ett tvåsidigt parat t-test utfördes för att påvisa om någon signifikant skillnad förelåg mellan analysresultaten. T-testet visade en statistisk signifikant skillnad på syretrycket (p = 0,04), syrgasmättnaden (p = 0,04), basöverskott (p = 0,001) och standardbikarbonat (p = 0,006), då medelvärdet ökade efter transport i rörpost. Medelvärdet för halten natriumjoner minskade efter transport i rörpostsystemet vilket innebar att hemolys inte förekom. Slutsatsen var att det finns en signifikant skillnad mellan blodgassprutor transporterade i rörpostsystem och blodgassprutor transporterade manuellt på vissa analyser, men skillnaden har ingen klinisk betydelse. / Blood gas syringe are ordered to examine the patient´s acid-base status, lactate concentration and electrolyte concentration. Some causes for imbalance could be trauma, lack of oxygen, infection, poisoning or starvation. In 2018, a new pneumatic tube transport system was installed at Västervik´s hostpital and the purpose of this study was to investigate if it is possible to transport samples for blood gas analyses with the new pneumatic tube transport system without affecting the test results. The analyses which were investigated were pH (power of hydrogen), oxygen tension, carbon dioxide tension, saturation, sodium ions, potassium ions, free calcium ions, standard bicarbonate, base excess and lactate. The study included 27 arterial double samples, one samples was transported in the pneumatic tube transport system and the other was manually transported to the laboratory. The samples were analysed within 30 minutes after the sampling, on the ABL 800 Flex instrument, using the methods potentiometry, amperometry and spectrophotometry. The results were compared using a correlation diagram with a regression line to study the relationship between the parameters. The correlation diagram shown a positive linear correlation and a relationship could be demonstrated for all the parameters (r = 0,929-0,998). If the results from the samples transported manually increased, the results also increased from the samples transported in the pneumatic tube transport system and vice versa. A bar chart was created to visualize differences in the mean values. A difference could be seen in base excess and the mean value increased after transport in the pneumatic tube transport. A two-sided paired t-test was performed to demonstrate any significant difference between the parameters. The t-test demonstrated a significant difference in the oxygen tension (p = 0,04), oxygen saturation (p = 0,04), base excess (p = 0,001) and the standard bicarbonate (p = 0,006) and statistically the values was higher after transport with the pneumatic tube transport system. The mean value for sodium ions decreased after transport in the pneumatic tube transport system and that indicate that hemolysis did not occur. The conclusion of the study was that there is a significant difference between blood gas syringes transported with pneumatic tube transport system and blood gas syringes transported manually, but the differences are not clinically relevant.

Este trabalho inicia com um estudo monográfico do comportamento químico do íon tiocianato, do ácido isotiociânico e uma rápida revisão da literatura sobre a reação uranilo/tiocianato. Foi feita uma rápida apreciação sobre os métodos de cálculos de constante de estabilidade e uso de métodos indiretos. A estabilidade dos complexos de tiocianato de mercúrio (II) foi estimada através de medidas potenciométricas com a finalidade de verificar a ordem de variação de seu ñ, dentro de larga faixa de concentração de tiocianato, com opropósito de utilizar este sistema como indicador de ligante livre em estudos de equilíbrios. A formação do ácido isotiociânico foi estudada por um método indireto, utilizando Hg(SCN)x2-x/Hg como sistema indicador para [SCN-]. Este estudo foi feito a 25&#176;C e em força iônica 2,0 M e 4,0 M, obtendo-se: &#946;HNCS = 0,135 &#177; 0,0070 (em força iônica 2,0 M). &#946;HNCS = 0,168 &#177; 0,0069 (em força iônica 4,0 M). sendo: (ver fórmula no PDF). Estes valores de constante foram obtidos através de aproximações sucessivas, envolvendo cálculos iterativos das concentrações livres das espécies reagentes seguindo do tratamento da bem conhecida função Fo (X). Nas medidas potenciométricas também foi estimado &#916;Ej causado pela presença de [H+], com base na variação de ESO\' de um eletrodo de Cl-, AgCl/Ag, trabalhando-se em condições semelhantes. O sistema uranilo/tiocianato foi também estudado potenciometricamente e da mesma maneira, em meio fortemente ácido, onde a concentração de HNCS formado deve ser considerada. Foi determinada a formação de cinco espécies sucessivas: &#946;1 = 11,4 &#177; 0,06 K1 = 11,4 &#946;2 = 49,0 &#177; 0,82 K2 = 4,30 &#946;3 = 88,4 &#177; 3,25 K3 = 1,80 &#946;4 = 127,4 &#177; 4,42 K4 = 1,44 &#946;5 = 91,4 &#177; 1,82 K5 = 0,72. Evidências da existência da sexta espécie foram encontradas, mas seu valor apresentou elevada incerteza. Foram feitas medidas espectrofotométricas em comprimentos de onda entre 280 e 300 nm para o urânio em meio de concentrações crescentes de tiocianato. O sistema apresenta forte absorção, com absortividades molares médias maiores que 7700 1.mol.cm-1, o que é de interesse analítico. A combinação das constantes de formação com os dados espectrofotométricos levou às absortividades molares individuais dos complexos. / This thesis start with a monographic study on the chemical behaviour as thiocyanate ion, the iso-thiocyanic acid and a revision on the uranyl-thiocyanate reaction. A short and critical comment on methods on computation of stability constants and use of indirect methods was included. The stability of mercury(II)/thiocyanate complexes was estimated by potentiometric measurements in order to check the range of its ñ variations, at a wide thiocyanate ion concentration, in order to use this sistem as indicator of the free ligand concentrations in equilíbria studies. The formation of iso-thiocyanic acid wasstudied by an indirect potentiometric method by using Hg(SCN)x2-x/Hg as an indicator system for [SCN-]. This was performed at 25&#176;C and ionic strength 2,0 M and 4,0 M. &#946;HNCS = 0,135 &#177; 0,0070 (at ionic strength 2,0 M). &#946;HNCS = 0,168 &#177; 0,0069 (at ionic strength 4,0 M). being: (see in the archive PDF). This constant values were obtained from a systematic approach involving iterative calculation of the free concentrations of the reacting species and final treatment of the well known Fo (X) function. The potentiometric measurements include an estimation of &#916;Ej by the presence of [H+], on basis of ESO\' changes of a Cl-, AgCl/Ag electrode, working at comparable conditions. The system uranyl/thiocyanate was also potentiometrically studied on the same basis at a fairly acid medium, where HNCS formation needs to be corrected. Five ligand stepwise complexes were found: &#946;1 = 11,4 &#177; 0,06 K1 = 11,4 &#946;2 = 49,0 &#177; 0,82 K2 = 4,30 &#946;3 = 88,4 &#177; 3,25 K3 = 1,80 &#946;4 = 127,4 &#177; 4,42 K4 = 1,44 &#946;5 = 91,4 &#177; 1,82 K5 = 0,72. Evidences of sixth specie was found, but its formation constants was still of uncertain magnitude. Spectrophotometric measurements were take at 280-300 nm for uranyl in increasing thiocyanate concentration. The system present strong absorption, with an average molar absorbtivity higher than 7.700 1.mol.cm-1, which is interesting for analytical purposes. The combination of the formation constants with the spectrophotometric data lead to individual molar absortivities of the complexes.

O ferro é o elemento mais abundante na Terra e tem importante papel em ciclos biogeoquímicos Neste trabalho foi desenvolvido um procedimento analítico automático para a determinação fotométrica de ferro em águas de rios, empregando um fotômetro baseado em LED e mini-bombas solenoide para o gerenciamento de soluções. O procedimento proposto foi baseado na reação do ferro (III) com o tiocianato de potássio formando um complexo avermelhado com máximo de absorção em 470 nm. Para a determinação de ferro total foi incluída uma etapa de oxidação em linha, usando uma solução de persulfato (S2O82-) como oxidante. O módulo de análises foi constituído por quatro mini-bombas solenoide e uma válvula solenoide de três vias. Para a obtenção de sinais foi construído um fotômetro composto por uma cela de fluxo com caminho óptico de 50 mm, um LED azul (\'lâmbda\'=470 nm) e um fotodetector. Visando utilizar este equipamento portátil para medidas em campo, foram empregadas duas baterias de 6 V para alimentar os dispositivos ativos. Os ensaios em laboratório mostraram que as baterias permitem uma autonomia de mais de 50 horas de trabalho sem recarregá-las. O procedimento desenvolvido apresentou as seguintes características analíticas: resposta linear entre as concentrações de 0,25 e 4,0 mg L-1, segundo a equação Y = (0,0183 ± 0,003) + (0,15326 ± 0,002)X (r=0,9997); limite de detecção 0,013 mg L-1 Fe (III) estimado com 99,7 % de confiança; desvio padrão relativo estimado em 0,95 % (n=15) obtido com uma solução de concentração de 1,5 mg L-1 Fe (III); frequência de amostragem de 50 determinações por hora. Os resultados obtidos pelo procedimento proposto e pelo de referência não apresentaram diferenças significativas com nível de confiança de 95 % / Iron is the most abundant element on Earth and plays an important role in biogeochemical cycles. In this work, an automatic analytical procedure was developed for the photometric determination of iron in river waters, employing a LED-based photometer and solenoid mini-pumps for solution handling. The proposed procedure was based on the reaction between iron (III) and potassium thiocyanate, yielding a red complex with maximum absorption at 470 nm. For the determination of total iron, an in line oxidation step was included, employing a persulfate solution (S2O82-) as oxidant. The module was constructed with four solenoid mini-pumps and a three-way solenoid valve. For data acquisition a photometer was constructed with a 50 mm optical path flow cell, a blue LED (\'lâmbda\'= 470 nm) and a photodetector. Envisioning the use of this portable equipment in field, two 6-Volt batteries were employed to supply energy to the active devices. Laboratory tests showed that the batteries provide more than 50 hours of operation without recharging. The proposed procedure showed the following analytical features: linear response between 0.25 and 4.0 mg L-1, according to the equation Y = (0.0183 ± 0.003) + (0.15326 ± 0.002) X (r = 0.9997); detection limit of 0.013 mg L-1 Fe (III), estimated with 99.7 % of confidence; relative standard deviation estimated as 0.95% (n = 15), obtained with a 1.5 mg L-1 Fe (III) solution; sampling rate of 50 determinations per hour.The results obtained with the proposed and reference procedure did not show significative differences at a 95% confidence level

O cetoconazol é um derivado imidazólico com atividade antifúngica, empregado no tratamento de grande variedade de infecções cutâneas. O objetivo deste trabalho foi a padronização e a validação dos métodos analíticos empregando-se a espectrofotometria no ultravioleta ( UV ) por derivada de primeira ordem e a cromatografia líquida de alta eficiência (CLAE) para a determinação do cetoconazol em formulações farmacêuticas sob a forma de creme obtidas no comércio e formuladas em laboratório. O estudo da estabilidade física das formulações obtidas em laboratório foi realizado após o armazenamento sob diferentes condições de tempo, temperatura e umidade. O método espectrofotométrico no UV por derivada de primeira ordem foi padronizado a 257nm , no intervalo de concentração de 5,0 a 30,0 &#181;g/mL em metanol. O coeficiente de correlação linear foi de 0,9997, o percentual de recuperação foi de 100,24%. A média do desvio padrão relativo foi de 0,56% para a amostra simulada e 0,41% para a amostra comercial. A determinação de cetoconazol por CLAE foi realizada empregando-se uma coluna LiChrospher® 100 RP- 18 ( 5&#181;m ) e fase móvel constituída por uma mistura de trietilamina em metanol( 1:500 ) e solução de acetato de amônio em água (1:200 ) na proporção de 75 : 25 v/v, com vazão de 1,0 mL/min e detecção no UV a 225 nm. O terconazol foi utilizado como padrão interno. O coeficiente de correlação linear foi de 0,9981, o percentual de recuperação foi de 100,88%, a média do desvio padrão foi de 2,13% para a amostra simulada e 1,25% para a amostra comercial. A amostra simulada apresentou comportamento pseudoplástico e tixotropia em decorrência das medidas reológicas obtidas experimentalmente. / Ketoconazole is an imidazole antifungal agent used in the treatment of great variety of skin infectious diseases. The aim of this research was the standardization and the validation of two analytical methods, first derivative ultraviolet ( UV ) spectrophotometry and high performance liquid chromatography( HPLC ) to determine ketoconazole in commercial and simulated cream dosage forms preparations. The validated methods were used to study the stability of the simulated cream after storage under high temperatures and high percentage of humidity. First derivative UV spectrophotometry was standardized at 257 nm, in a range of concentration from 5.0 to 30.0 &#181;g/mL in methanol. The coefficient of correlation was 0.9997 and the recovery average was 100.24%. The average relative standard deviation ( RSD ) was 0.56% for simulated preparation and 0.41 % for commercial preparation. The determination of ketoconazole by HPLC was performed using a LiChrospher® 100 RP-18(5&#181;m ) column, a mobile phase consisting of triethylamine in methanol (1:500) and ammonium acetate solution in water(1:200 ) 75:25 ( v/v ), a flow rate of 1.0 mL/min and UV detection at 225nm. Terconazole was used as internal standard. The coefficient of correlation was 0.9981, the recovery average was 100.88%, the average relative standard deviation ( RSD ) was 2.13% for the simulated preparations and 1.25% for the commercial preparations. The rheological measurements showed that the simulated preparation presented pseudoplastic and thixotropic behavior.

A linezolida é um antibiótico oxazolidinona efetivo contra bactérias patogênicas gram-positivas, incluindo Staphylococcus aureus resistente a meticilina (MRSA), Staphylococcus aureus resistente a glicopeptídeos (GISA) e enterococci resistente a vancomicina (VRE). As oxazolidinonas inibem a translação bacteriana na fase de iniciação da síntese de proteínas, enquanto que a síntese de RNA e DNA não são afetadas. Diversos métodos por cromatografia líquida de alta-eficiência (HPLC) têm sido relatados para a determinação da concentração de linezolida em plasma humano, soro e urina. Entretanto, um número pequeno de métodos estão disponíveis para a determinação de linezolida em formulações farmacêuticas. O objetivo deste trabalho foi desenvolver e validar métodos espectrofotométrico, de cromatografia líquida de ultraeficiência em fase reversa (RP-UPLC), doseamento microbiológico em placas e doseamento microbiológico rápido em microplacas com leitura cinética para a determinação de linezolida em soluções injetáveis e comprimidos. Adicionalmente, foram identificadas e quantificadas as principais fontes de incerteza relacionadas aos métodos. O desenvolvimento dos métodos utilizou uma abordagem racional, empregando-se planejamento de experimentos (análise fatorial e metodologia de superfície resposta) para otimização das condições analíticas. As fontes de incertezas foram identificadas empregando-se diagrama de Ishikawa e quantificadas conforme procedimento da Eurachem/Citac. Os métodos desenvolvidos apresentaram especificidade/seletividade, linearidade, precisão, exatidão e robustez adequadas, conforme os critérios estabelecidos pelo ICH e ANVISA. A análise estatística demonstrou equivalência entre os resultados providos por cada um dos métodos, sendo intercambiáveis entre si. Portanto, os métodos podem ser empregados no controle de qualidade de rotina na indústria farmacêutica. / Linezolid is an oxazolidinone antibiotic effective against gram-positive pathogenic bacteria, including methicillin-resistant Staphylococcus aureus (MRSA), glycopeptide-intermediate Staphylococcus aureus (GISA) and vancomycin-resistant enterococci (VRE). Oxazolidinones inhibit bacterial translation at the initiation phase of protein synthesis, while RNA and DNA synthesis are not affected. Several high performance liquid chromatographic (HPLC) methods have been reported to determine the concentration of linezolid in human plasma, serum and urine. However, a few number of methods are available to determine the concentration of linezolid in pharmaceutical dosage forms. The aim of the present work was to develop and validate a spectrophotometric method, a reverse-phase ultra-high performance liquid chromatographic method, microbiological assay and microbiological rapid assay in microplates using kinetic reading for the determination of linezolid in injections and tablets dosage forms. In addition, the most important sources of uncertainty were identified and quantified for each method. A rational approach was used in the development of these methods, using design of experiments (factorial design and response surface methodology) for optimization of analytical conditions. The sources of uncertainties were identified using Ishikawa diagram and quantified as described in Eurachem/Citac procedure. The developed methods were specific/selective, linear, precise, accurate and robust, as required by ICH and ANVISA guidelines. Statistical analysis showed equivalence among the results provided by each method, being interchangeable. Thus, the methods may be employed in routine quality control analysis by pharmaceutical industry.

Esta tese tem como foco o desenvolvimento de procedimentos analíticos automáticos, visando as determinações fotométricas de vanádio e de estanho em águas e em alimentos empregando o processo de multicomutação em fluxo. Um microcontrolador da família PIC e um programa escrito em linguagem Visual Basic 6.0 foram empregados para controle dos dispositivos e aquisição de dados. A unidade de detecção foi construída empregando LED de alto brilho e celas de fluxo com longo caminho óptico (50-200 mm) para ganho em sensibilidade. O módulo de análises, empregando bombas solenoide como propulsores de fluido e o fotômetro foram integrados, formando uma unidade compacta. A determinação de vanádio em águas, mineral e de rio, foi baseada na redução do V(V) à V(IV) com ácido ascórbico e posterior complexação com Eriocromo Cianina R (ECR). Empregando uma cela de 150 mm, o sistema apresentou resposta linear de 0,02 a 1,00 mg L-1, limite de detecção estimado em 13 ?g L-1, coeficiente de variação de 0,87% (n=10) e frequência analítica de 47 determinações por hora. Recuperações entre 89 e 109% foram obtidas para adição de V(V) nas amostras de águas. O procedimento para a determinação de estanho em alimentos foi desenvolvido empregando bomba de multi-seringa como unidade de propulsão de fluidos, cela de fluxo com caminho óptico de 200 mm e parada de fluxo de 50 s. Baseado na reação do Sn(IV) com o violeta de pirocatecol (PCV) na presença de surfactantes, o sistema apresentou resposta linear de 0,10 a 1,25 mg L-1, limite de detecção estimado em 0,04 mg L-1, coeficiente de variação de 1,30% (n=10) e frequência analítica de 49 determinações por hora. Recuperações entre 95 e 115% foram obtidas com a adição de Sn(IV) às amostras de alimentos. / Automatic analytical procedures for photometric determinations of vanadium in water and tin in foods were developed using the multicommutation flow analysis process. A microcontroller of the PIC family and a software written in Visual Basic 6.0 language were used for devices control and data acquisition. Detection unit was designed to use high brightness LED and long optical pathlength flow cells (50-200 mm) to improve sensitivity. The flow analysis module using solenoid mini-pumps as fluid propelling devices and the photometer were integrated in order to form a compact unit. The determination of vanadium in mineral and river waters was based on the reduction of V(V) to V(IV) with ascorbic acid and subsequent complexation with Eriochrome Cyanine R (ECR). Employing flow cell of 150 mm, the system presented linear response between 0.02 and 1.00 mg L-1, detection limit of 13 ?g L-1, variation coefficient of 0.87% (n=10) and sampling throughput of 47 determinations per hour. Recoveries between 89 and 109% were attained for vanadium spiked to mineral and river water. The procedure for determination of tin in foods was development employing a multi-syringe pump as fluid propelling device, a flow cell with optical pathlength of 200 mm and stop flow of 50 s. The procedure was based on the reaction of Sn(IV) with pyrocatechol violet (PCV) in the presence of surfactants, presented linear response between 0.10 and 1.25 mg L-1, detection limit of 0.04 mg L-1, variation coefficient of 1.30% (n=10) and sampling throughput of 49 determination per hour. Recoveries between 95 and 115% were attained for tin spiked samples