The purpose for this study was to determine the element composition in CoffeeBricks before and after incineration. The difference between element composition in CoffeeBricks (barbecue briquettes made out of spent coffee grounds) and regular barbecue briquettes was also evaluated in this study. Aqua regia digests from the ash residues of CoffeeBricks and the ash residues of regular barbecue briquettes were analyzed with Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). H2SO4/H2O2 digests from unburned CoffeeBricks and plain spent coffee grounds were also analyzed with ICP-AES in order to evaluate the concentration for selected elements before and after incineration. The chosen elements evaluated in this study had concentrations higher than 0.1 ppm in the measured samples according to the ICP-AES analyses. Element concentrations are presented as mg trace element/g ashes or mg trace element/g sample. The ash residues of regular barbecue briquettes contained higher concentration of Al, Ca, Fe, Mg and S.The ash residues of CoffeeBricks contained higher concentration of B, Cu, Fe, K, Mn, Na and P. One-way ANOVA showed that there were differences in concentration for the elements Ca, K, P, Na and S between the ash residues of the two different types of CoffeeBricks and regular barbecue briquettes for <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Calpha" />=0.001. One-way ANOVA also showed differences in concentration for the elements Ca, K, P and Na between the two different types of unburned CoffeeBricks and plain spent coffee grounds for <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Calpha" />=0.01.

Inositol phosphates (IPs) represent a major part of the organic phosphorus found in the environment, which makes their identification and quantification very important. The goal of this project was to explore the possibility of quantification of IPs with inductively coupled plasma - atomic emission spectrometry (ICP - AES). This paper deals with the creation of an in-house IP standard and the considerations for the successful linking of high performance liquid chromatography (HPLC) with ICP - AES. Experiments with different nebulizers, mobile phases, standard solutions and model substance were performed. The proposed optimal conditions for the ICP experiments are: the use of a modified Lichte nebulizer, mobile phase without methanol and the use of standards matched to the mobile phase. Adenosine monophosphate (AMP) was found to be a good model substance and showed that the band broadening from HPLC to ICP – AES was approximately a factor of 2. Limits of detection for AMP were 5 µM for HPLC and 20 µM for ICP – AES. The optimal way to create an in-house standard was using the potassium salt of IP6 and treating it for 90 minutes at a temperature of 120 ºC with 3.2 M acetic acid.

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Submitted by Felipe Lapenda (felipe.lapenda@ufpe.br) on 2015-03-06T13:48:11Z No. of bitstreams: 2 TESE Herika Maria da Silva Barbosa.pdf: 5271997 bytes, checksum: f191ae7b9a0e5275b7cc9f864a18ac40 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-06T13:48:11Z (GMT). No. of bitstreams: 2 TESE Herika Maria da Silva Barbosa.pdf: 5271997 bytes, checksum: f191ae7b9a0e5275b7cc9f864a18ac40 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2014-10-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / As rochas são degradadas física e quimicamente a partir do intemperismo. Neste processo têm grande importância os liquens, pois seus fenóis ao percolarem para os substratos promovem a quelação com íons dos minerais contidos nas rochas a eles subjacentes. Sabe-se que o nitrogênio tem marcada influência no metabolismo dos liquens, induzindo-os a uma maior produção de fenóis. Neste trabalho objetivou-se investigar a ação do ácido úsnico (USN) produzido pelo líquen Cladonia substellata Vainio sobre amostras de granito procedentes de Sirinhaém e Cabo de Santo Agostinho, bem como basalto procedente de Sirinhaém, Pernambuco, Brasil. Foram utilizados parâmetros de incremento do processo de intemperismo como o emprego de fonte nitrogenada, na forma de ureia, para aumento da biossíntese do USN por C. substellata e o aumento da temperatura (28°C±3 e 42°C±3) como acelerador da velocidade das reações químicas entre íons das rochas e USN. O ácido oxálico comercial (AOX) foi utilizado como controle positivo e as rochas borrifadas com água foram consideradas como controle negativo. Amostras de C. substellata foram coletadas em Mamanguape, Paraíba, Brasil e montados experimentos contendo líquen in natura depositado sobre as rochas trituradas. O material controle foi borrifado com água deionizada em dias alternados e o material tratado foi borrifado com ureia uma vez por semana, nas concentrações de 1%; 0,1% e 0,01% durante seis meses, sendo as amostras rochosas e liquênicas coletadas e avaliadas por Cromatografias em Camada Delgada (CCD), Cromatografia Líquida de Alta Eficiência (CLAE), Espectrofotometria, Teste de vitalidade celular com Azul de Evans e Vermelho Neutro. As rochas, antes e depois dos experimentos, foram avaliadas por microscopia petrográfica, Difratometria de Raios-X e Espectrometria de Emissão Atômica por Plasma Indutivamente Acoplado (ICP/ AES). Os resultados demonstraram que o líquen produziu compostos químicos e que estes foram repassados para as rochas, tendo sido incrementada sua biossíntese pela adição de ureia a 1% e 0,1%. Através do CLAE foi detectado USN nas amostras rochosas. Nos ensaios de vitalidade celular por Azul de Evans e Vermelho Neutro observou-se que nos experimentos borrifados com soluções de ureia a 1% o líquen sofreu maiores danos à sua estrutura e apresentou maior número de células mortas, porém mesmo assim continuou ativo e produzindo fenóis. Nas DRX-s das rochas testadas foram evidenciadas alterações principalmente na albita e no ortoclásio em contato com o USN e de maneira geral foi menos intensa no quartzo. Na maior parte dos experimentos a temperatura foi o fator que mais contribuiu para intensificar a interação entre as rochas com o USN e o AOX. Os dados mineralógicos (DR-X) foram complementados pelas análises químicas de ICP/ AES que comprovaram a quelação de íons rochosos, principalmente diante da temperatura elevada (T=42°C±3). Os íons mais facilmente quelados dos granitos e do basalto foram o Ca, Fe, K, Mg e Si. Foi possível concluir que o USN tem ação pedogenética comparável ao AOX e que fonte exógena de nitrogênio, bem como o aumento da temperatura, incrementam a ação dessa substância.

Lubricant is a common name for a large group of products that are essential for almost every engine or other machinery equipment that include mechanical part movements. Their main application is reduction of the friction between two rubbing surfaces by interposing a lubricating film between them. Other important functions of lubricants beside lubrication are; heat transfer, energy efficiency enhancement, corrosion and oxidation protection. All types of lubricants mainly consist of base oil and additives. Base oils are mainly hydrocarbon compounds, while additives are various chemical compounds added to the base oil to enhance some of the already existing properties, or to impose new properties that are beneficial for application purposes. During the storage period, where different storage conditions can occur, many of the requirements for lubricants chemical and physical stability needs to be fulfilled. Inappropriate storage conditions can cause physical and chemical changes in lubricants, which can make them unusable for the intended application. The effects of different storage conditions on lubricants stability were investigated in this work. The experimental part of this project was conducted at Fuchs Lubricants Sweden AB. At the beginning of the experiment, twelve 2L high density polyethylene bottles (HDPE) filled with the lubricant, were divided into three groups. The first group consisted of four closed HDPE bottles previously filled with the lubricant that were stored at 9 °C, 22 °C, 45 °C and 80 °C. The second and the third group consisted also of four open bottles and four bottles with added distilled water stored at the same storage temperatures. The amount of lubricant was approximately the same in all bottles. At different time intervals sample aliquots from the top, middle and the bottom layer were taken from these bottles and analyzed. The effects of different storage conditions on the lubricant’s stability and homogeneity were acquired by two distinctive spectroscopic methods. Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) was used for elemental composition analysis, while the Fourier Transform Infrared (FTIR) Spectroscopy was used for evaluation of chemical changes on molecular level. Results from ICP-AES analyses showed almost homogeneous elemental distribution, virtually unaffected by different storage conditions in all sample bottles. Results from FTIR analyses showed that observed changes in absorption peaks (673, 863, 972. and 1267 cm-1) took place almost simultaneously at all three layers in all bottles stored at four different temperatures. These results suggest that the analyzed lubricant was stable and homogeneous for the observed period. The lowest storage temperature caused minimal changes in the lubricant and can be considered as optimal storage temperature for this product. It was also observed that increased temperature, direct exposure to oxygen and presence of water catalytically affected the rate of these changes. A part of this project was to validate the method used for ICP analysis. For this purpose, the following method performance parameters were investigated: linearity, precision, accuracy, Limit of detection (LOD) and Limit of quantification (LOQ). The obtained results showed that linearity of the method for all elements, in the used standard, was confirmed based on the set criteria. Precision and accuracy were tested in repeatability conditions and at four different concentration levels. The obtained results showed that accuracy of the method increased with concentration, and was highest for 50 ppm, for almost all elements. The highest precision (&lt; 2 % RSD), for almost all elements was obtained for the concentration of 25 ppm. The LOD values were between 0.01 and 1.42 ppm while calculated LOQ values were between 0.04 and 4.73 ppm. / Smörjmedel är det gemensamma namnet för en stor produktgrupp som är nödvändig för nästan alla motorer eller annan maskinutrustning som inkluderar mekaniska delrörelser. Deras huvudsakliga tillämpning är att minska friktionen mellan två ytor i rörelse genom att införa en smörjfilm mellan dem. Andra viktiga funktioner förutom smörjning är; värmeöverföring, energieffektivisering, korrosion-och oxidationsskydd. Alla typer av smörjmedel består huvudsakligen av basolja och tillsatser. Basoljor är huvudsakligen kolväteföreningar medan tillsatser är olika kemiska föreningar som läggs till basoljan för att förbättra några av de befintliga egenskaperna eller att införa nya egenskaper som är fördelaktiga för applikationsändamål. Under lagringsperioden, där olika lagringsförhållanden kan uppstå, måste många av kraven på smörjmedlens kemiska och fysikaliska stabilitet uppfyllas. Olämpliga lagringsförhållanden kan orsaka fysiska och kemiska förändringar i smörjmedlen som kan göra dem oanvändbara för avsedd användning. Effekterna av olika lagringsförhållanden på smörjmedelstabilitet undersöktes i detta arbete. Experimentell del av detta projekt genomfördes hos Fuchs Lubricants Sweden AB. I början av experimentet, tolv 2L högdensitetspolyetenflaskor (HDPE) fyllda med smörjmedlet, uppdelades i tre grupper. Den första gruppen bestod av fyra slutna HDPE-flaskor som ifylldes med smörjmedlet och som lagrades vid 9 ° C, 22 ° C, 45 ° C och 80 ° C. Den andra och den tredje gruppen bestod också av fyra öppna flaskor och fyra flaskor med tillsatt destillerat vatten lagrat vid samma lagringstemperaturer. Mängden av smörjmedel var ungefär lika i alla flaskor. Vid olika tidpunkter togs prov från topp-mitten-och bottenskiktet från dessa flaskor och analyserades. Effekterna av olika lagringsförhållanden för smörjmedelsstabiliteten och homogeniteten förvärvades genom två distinkta spektroskopiska metoder. Induktivt kopplad plasma atomemissions-spektroskopi (ICP-AES) användes för elementsammansättningsanalys medan Fourier transform infraröd spektroskopi (FTIR) användes för utvärdering av kemiska förändringar på molekylär nivå. Resultat från ICP-AES-analyser visade nästan homogen fördelning av element, opåverkad av olika lagringsförhållanden i alla provflaskor. Resultat från FTIR-analyser visade att observerade förändringar i absorptionstoppar (673, 863, 972 och 1267 cm-1) inträffade nästan samtidigt i alla tre skikten i flaskorna lagrade vid fyra olika temperaturer. Dessa resultat tyder på att det analyserade smörjmedlet var stabilt och homogent under den observerade perioden. Den lägsta lagringstemperaturen orsakade minimala förändringar i smörjmedlet och kan betraktas som den optimala lagringstemperaturen för denna produkt. Resultatet visade också att ökad temperatur, direkt exponering för syre och närvaro av vatten hade katalytiskt påverkat graden av dessa förändringar. En del av detta projekt var att validera metoden som används för ICP-analys. För detta ändamål undersöktes följande metodprestanda-parametrar: linjäritet, precision, noggrannhet, detektionsgräns (LOD) och kvantifieringsgräns (LOQ). De erhållna resultaten visade att linjäriteten för metoden, för alla element, i den använda standarden bekräftades baserat på uppsatta kriterier. Precision och noggrannhet testades i repeterbarhetsförhållanden och vid fyra olika koncentrationsnivåer. De erhållna resultaten visade att metodens noggrannhet ökade med koncentration och var högst för 50 ppm, för nästan alla element. Den högsta precisionen (&lt;2% RSD), för nästan alla element, erhölls för koncentrationen av 25 ppm. LOD-värdena var mellan 0.01 och 1.42 ppm medan beräknade LOQ-värden var mellan 0.04 och 4.73 ppm.

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal.

A produção industrial do café solúvel brasileiro destina-se, na sua maior parte, ao mercado externo, constituindo-se em um importante ítem de exportação do país. O objetivo do presente trabalho foi o desenvolvimento e aprimoramento de métodos de análise química adequados à investigação de componentes inorgânicos em café solúvel. Inicialmente foi definido o método de mineralização das amostras através da avaliação de 6 procedimentos diferentes, classificados em 3 classes: (I) microondas focalizado; (II) via úmida convencional e (III) sistema sob pressão em frascos de decomposição com tampas (bombas de teflon). As determinações dos nutrientes e contaminantes inorgânicos: Na, K, Mg, Al, P, S, Ca, Mn, Fe, Ni, Cu, Zn, Cd, Sb, Pb, Cr, Sn, As, Se e Hg, após a utilização do procedimento de mineralização que emprega o sistema de microondas focalizado com os reagentes HNO3 e H2O2, foram realizadas por espectrometria de emissão atômica com plasma induzido, ICP-AES (da nomenclatura inglesa Inductively Coupled Plasma-Atomic Emission Spectrometry). Interferências de matriz e/ou espectrais foram detectadas nas determinações de Pb, Cr, Sn, As, Se e Hg. No caso do Sn, optou-se pela correção da radiação de fundo através do software do equipamento, pois outras linhas de emissão deste analito eram menos sensíveis e igualmente sujeitas a interferências espectrais. Para o Pb e Cr a escolha de comprimentos de ondas alternativos eliminou os problemas de interferências espectrais devido à matriz das amostras. A aplicação das técnicas de geração de hidretos para o As e Se e a geração de vapor frio para o Hg, possibilitaram as determinações destes analitos nas amostras de café solúvel, aumentando a sensibilidade das análises. Os resultados obtidos para os teores dos nutrientes e contaminantes inorgânicos em 21 amostras de café solúvel disponíveis no mercado brasileiro, foram aceitáveis para o consumo humano, tanto no aspecto nutricional como toxicológico, com exceção de uma amostra com teor de Cr igual a 0,52 ± 0,02 mgKg-1, acima do permitido pela legislação brasileira que fixa o valor máximo de 0,10 mgKg-1. A aplicação de técnicas estatísticas, análise de clusters hierárquicos e componentes principais aos resultados obtidos, possibilitaram investigar a variabilidade das composições minerais e classificar grupos de amostras similares. O emprego da técnica instrumental ICP-AES através do sistema de nebulização convencional e a utilização do sistema de geração de hidretos e vapor frio, mostraram-se adequados para as determinações dos nutrientes e contaminantes inorgânicos em café solúvel, uma vez que níveis de precisão e exatidão aceitáveis foram obtidos. / The production of Brazilian soluble coffee is almost entirely destined for exporting. Therefore, the objective of this work was the development and the establishment of appropriate methods of chemical analysis of inorganic components in soluble coffee. Firstly, the appropriate digestion procedure for soluble coffee samples was defined through the evaluation of six different digestion techniques that were classified into three groups: (I) focused microwave system, (II) conventional wet digestion and (III) pressure digestion system in teflon bombs. The determinations of nutrients and toxic elements: Na, K, Mg, Al, P, S, Ca, Mn, Fe, Ni, Cu, Zn, Cd, Sb, Pb, Cr, Sn, As, Se, and Hg after the utilization of the focused microwave system with HNO3 and H2O2 reagents, were made by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) technique. Matrix and spectral interferences were detected in the determination of Pb, Cr, Sn, As, Se and Hg. Correction of the background enhancement by the equipment software was made in the determination of Sn, as other analytical lines were unsuitable for this application. For Pb and Cr, the choice of other analytical lines eliminated the problem of matrix and spectral interferences. The application of the hydride generation technique for As and Se and cold atomic vapour with ICP-AES for Hg, were suitable methods to determine these analytes in soluble coffee samples with increased sensitivity of the analysis. The results obtained of nutrients and toxic elements in twenty-one samples of soluble coffee collected from Brazilian market were acceptable to human consumption at nutritional and toxic level with exception of a sample with 0,52 ± 0,02 mgKg-1 of Cr, above the value specified in Brazilian Food Legislation, that fixes the maximum Cr contend in 0,10 mgKg-1. The aplication of statistical techniques analysis of principal components and the hierarchical cluster on the results of mineral compositions, enabled to investigate the variability in the composition and to classify groups of similar samples. The application of the ICP-AES technique using the conventional pneumatic nebulization system, the hydride generation technique and the cold vapour for Hg were suitable to determine the nutrients and toxic elements in soluble coffee, as they provided acceptable results indicating accuracy and precision.

Espectrometria de emissão óptica, utilizando plasmas acoplados indutivamente, torna-se uma ferramenta indispensável para análises de elementos químicos. Neste trabalho é descrita a construção detalhada de um oscilador de rádio frequência para obtenção de uma tocha de plasma indutivo. O projeto é estruturado a partir da elaboração da fonte retificadora, da malha de acoplamento, até a construção da tocha, além de análises com amostras líquidas e sólidas. Pelo fato de a tocha de plasma indutivo ser mais estável do que outros métodos de atomização, como laser ou chama, a torna uma escolha atraente para métodos analíticos, em vasta gama de aplicações. Os resultados do desempenho elétrico do oscilador de rádio frequência foram alcançados, embora as perdas sejam eminentes, foi obtida uma tensão na malha de acoplamento de 620 volts, potência na tocha de 1400 watts, e frequência do oscilador, com valor estável de 13,56 mega-hertz. Os resultados das análises também foi outro ponto de destaque, uma vez que, foi possível detectar através de um espectrômetro óptico, todos os elementos contidos numa solução de aço inox, tais como: silício, fósforo, manganês, molibdênio, cromo, níquel e cobre, embora os resultados quantitativos ainda necessitem de alguns ajustes. Com relação à análise de amostras sólidas, onde foram utilizados eletrodos consumíveis de alumínio e cobre, o resultado foi muito promissor, graças ao projeto da tocha que permite modificações em sua estrutura; os eletrodos consumíveis também foram analisados com as técnicas de difração de raio-X e microanálise por feixe de elétrons para confirmação dos resultados. / Optical emission spectrometry using inductively coupled plasma becomes an indispensable tool for analysis of chemical elements. This work describes the detailed construction of a radio frequency oscillator for obtaining an inductive plasma torch. The project is structured from the elaboration of the source rectifier, matching network, until the construction of the torch, and analyzes with liquid and solid samples. Because the inductive plasma torch to be more stable than other atomization methods such as laser or flame, becomes an attractive choice for analytical methods in wide range of applications. The results of the electrical performance of the radio frequency oscillator been achieved, although losses are distinguished was obtained at a voltage matching network 620 volts, the torch power of 1400 watts, and oscillator frequency, with a steady value of 13.56 mega-hertz. The results of analyzes was also another important point, since it was possible to detect through an optical spectrometer, all elements contained in a solution of stainless steel, such as silicon, phosphorus, manganese, molybdenum, chromium, nickel and copper, although the quantitative results still need some tweaking. Regarding the analysis of solid samples, which were consumable electrodes of aluminum and copper, the result was very promising, due to the torch project that allows modifications in its structure; consumable electrodes were also analyzed through the techniques x-ray diffraction and microanalysis by electron beam, to confirm the results.

L’application de la biosorption à l’analyse inorganique est un sujet en plein essor. Dans cette étude, un support à base de cellules de boulanger Saccharomyces cerevisiae a été développé pour la spéciation et la préconcentration des espèces inorganiques de l’antimoine Sb(III) et Sb(V). Nous avons tout d’abord montré qu’il était possible de fixer de manière sélective Sb(III) en présence de Sb(V) sur les cellules dans une large gamme de pH (5-9) et de force ionique (0-0,1M). Un prétraitement thermique de la biomasse (80°C, 30min) permet d’augmenter significativement la cinétique de fixation de Sb(III) sans nuire à la séparation. L’élution de Sb(III) par l’acide thioglycolique à pH 10 est rapide et quantitative, permettant d’obtenir un facteur de préconcentration proche de 9. Nous avons mis en évidence que la rétention de Sb(V) observée à bas pH était due à des complexation avec les groupements sulfhydryle de la paroi cellulaire. La modélisation des isotherme de sorption de Sb(III) (qmax = 450µg.g-1) ont permis de définir 3 types de sites d’affinité et de coordination différentes. Parmi les matrices testées pour l’immobilisation des cellules, le polysulfone s’avère être le plus performant, alliant perméabilité, faible affinité vis-à-vis de l’antimoine et préservation des sites de fixation. Des colonnes remplies de levures immobilisées ont été couplées à un spectromètre ICP-AES et appliquées avec succès à la spéciation de l’antimoine dans l’eau minérale dopée à faible concentration. Les limites de quantification de Sb(III) ont été améliorées d’un facteur 5 par préconcentration / The application of biosorption to inorganic analysis is an expanding research area. In this study, an analytical support based on baker’s yeast Saccharomyces cerevisiae was developed for the speciation and the preconcentration of inorganic antimony species Sb(III) and Sb(V). It was shown that Sb(III) can be retained selectively by the cells in the presence of Sb(V) in a wide range of pH (5-9) and ionic strength (0-0,1M). Heat pretreatment of the biomass (80°C, 30min) significantly increased the kinetics of Sb(III) uptake without degrading the separation. The elution of Sb(III) by thioglycolic acid at pH 10 was rapid and quantitative, allowing to achieve a preconcentration factor close to 9. Interactions between Sb(V) and the cells, as observed at lower pH, were found to be purely electrostatic, while Sb(III) retention was attributed to the complexation of the species with sulfhydryl groups of the cell walls. Three kinds of sites with different affinities and coordinations were identified by modeling Sb(III) sorption isotherms (qmax = 450µg.g-1). Among the different materials tested, polysulfone was found to be the most suitable matrix for yeast immobilization, combining a good permeability to a low affinity for antimony species and preservation of the sorption sites. Columns filled with immobilized cells were coupled with ICP-AES and successfully applied to antimony speciation in mineral waters samples spiked at low concentration level. The limit of quantification was improved by a factor of 5 by preconcentration