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Izmer, Andrei. "Method development using ICP-MS and LA-ICP-MS and their application in environmental and material science." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=981659799.
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Wintergerst, Mieke. "Detection of inositol phosphates with HPLC-ICP-AES : Method development." Thesis, Uppsala universitet, Analytisk kemi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-202003.
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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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SANTOS, EIDER FERNANDO ALVES DOS. "DEVELOPMENT OF A METHOD FOR MULTIELEMENTAL DETERMINATION IN BIODIESEL BY ICP-MS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=18855@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROOs elementos de maior interesse no biodiesel são os resíduos de catálise do processo produtivo (Na e K), os delimitados por legislação ambiental vigente (S, por exemplo) e os elementos venenosos aos catalisadores automotivos (Pb, V, P e Hg); porém, pesquisas orientadas no sentido de produzir metodologias analíticas para a realização de determinações em biodiesel vêm buscando um mapeamento elementar mais completo do combustível. Técnicas como ICP OES, ICP-MS com célula de reação/colisão, FAAS, GFAAS têm sido usualmente empregadas em determinações diretas ou não, mas ainda existem combinações de preparo de amostra e técnica analítica a ser pesquisadas. O presente trabalho teve como objetivo a avaliação de um sistema de decomposição ácida de amostra de biodiesel, visando à decomposição ácida da maior quantidade possível de matéria orgânica presente na matriz e a consequente determinação em ICP-MS. O processo de decomposição ácida, avaliado pela concentração de carbono residual, determinado em ICP OES, não requer grandes quantidades nem de energia térmica e nem do agente oxidante e ainda permite, após processo de redução da matriz nítrica remanescente, uma determinação direta em ICP-MS utilizando padrões aquosos na confecção das curvas e sem a necessidade de célula de colisão/reação. Foram determinados Ag, Ba, Cu, Mn, Mo, Ni, Ti e Zn em amostras de biodiesel de 4 matérias-primas diferentes e em duas amostras certificadas de biodiesel (NIST) e, tanto os resultados de recuperação, que variaram entre 90 e 110 por cento, quanto o comparativo realizado com as metodologias por ICP OES, validaram os resultados.
Biodiesel appeared in this scenario as an alternative short-term, compatible with the current technologies and without the necessity of major modifications. The elements of greatest interest are the residue of catalyst of the production process (Na, K), those limited by environmental regulations (S) and those that act like poisons for the catalyst system of vehicles (Pb, V, P and Hg), but researches aimed to produce analytical methodologies for determinations in Biodiesel, have sought to achieve a multielement mapping of the fuel (Woods ET AL, 2007). Techniques like ICP OES, ICP-MS with reaction cell, FAAS, GFAAS have been usually used in direct or indirect determinations, but still there are combinations of sample preparation and analytical techniques to be studied. This present work sought to evaluate an analyzing system in ICP-MS after a digestion procedure looking for the minimal quantity of organic matter at the final sample. The preliminary results showed that the digestion process, evaluated by the concentration of residual carbon determined by ICP OES, it can be fast and does not require large amounts of energy and oxidizing agent. And still allow, after reducing the nitric matrix, the use of aqueous standards at the calibration curve. It was monitored Ag, Ba, Cu, Mn, Mo, Ni, Ti and Zn in 4 different sources of raw material for biodiesel, and the method was validated by the analysis of two NIST standards by the comparison with ICP OES results and by the recover results ranged between 90 and 110 per cent.
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SOUZA, JEFFERSON RODRIGUES DE. "METHOD DEVELOPMENT FOR THE DETERMINATION OF TOTAL SE BY ICP-MS AND ITS SPECIES BY HPLC-ICP-MS IN FOOD SUPPLEMENT AND IN ISOTOPICALLY ENRICHED YEAST." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2017. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=33733@1.
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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIROCOORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE SUPORTE À PÓS-GRADUAÇÃO DE INSTS. DE ENSINO
O consumo de suplementos alimentares tem apresentado um aumento significativo nos últimos anos principalmente pelo grande apelo desse produto em relação a complementação da dieta com elementos essenciais e a melhora e manutenção da saúde. A combinação do crescente consumo e o livre acesso a esse produto, aliado a ausência de fiscalização por parte dos órgãos governamentais torna seu consumo descontrolado, um potencial risco a saúde da população. Nesse cenário o desenvolvimento de métodos analíticos destinados ao controle de qualidade incluindo a determinação da concentração de selênio total e de suas espécies torna-se uma necessidade. Para isso, foram desenvolvidas metodologias para a quantificação de selênio total por ICP-MS e suas espécies inorgânicas (Se IV e Se VI) e selenometionina por HPLC-ICP-MS em amostras de suplementos alimentares enriquecidos em selênio e em amostra de levedura enriquecida isotopicamente em 78Se. A metodologia para determinação de selênio total, utilizando diferentes gases de reação, foi otimizada empregando planejamento experimental e os limites de detecção encontrados foram entre 0,01 mg kg(-1) (CH4) e 0,1 mg kg(-1) (NH3) e a concordância com o MRC Selm-1 de entre 99 por cento (NH3) e 104 por cento (CH4). Os resultados encontrados referentes à concentração de selênio nas amostras de suplementos alimentares apresentaram uma discrepância em relação ao valor informado no rótulo entre -29 por cento e +170 por cento e, de maneira complementar, o acoplamento do HPLC ao ICP-MS permitiu realizar a especiação de selênio nas amostras de suplemento alimentar. O emprego das técnicas ICP-MS, HPLC-ICP-MS e ESI-MS possibilitou a caracterização de uma amostra de levedura enriquecida isotopicamente em 78Se em termos de sua distribuição isotópica, concentração de selênio total e selenometionina bem como proteínas com peso molecular de aproximadamente 12 kDa.
The consumption of dietary supplements has a significant increase in recent years mainly for a great appeal of this product in relation to a complementation of the diet with essential elements and an improvement and maintenance of health. The combination of increased consumption and free access to this product, associated to the lack in the inspection by government, makes their consumption uncontrolled and a potential risk to the citizen health. In this scenario the development of analytical methods for quality control, including a determination of the total selenium concentration and its species becomes a primordial necessity. For this, methodologies were developed for quantification of total selenium by ICP-MS and its inorganic species (Se IV and Se VI) and selenomethionine by HPLC-ICP-MS in samples of selenium-based food supplements and in isotopically enriched yeast sample in 78Se. The methodology for total selenium determination was optimized by experimental design and the limits of detection were in the range of 0.01 mg kg(-1) (CH4) and 0.1 mg kg(-1) (NH3) and the agreement with the CRM Selm-1 were between 99 percent (NH3) and 104 percent (CH4). The results found for selenium content in the food supplements samples presented a discrepancy in relation to the labeled value between -29 percent and + 170 percent and, complementarily, coupling of HPLC to ICP-MS allowed an speciation analysis in the food supplements samples. The use of the ICP-MS, HPLC-ICP-MS and ESI-MS techniques enabled a characterization of a 78Se isotopically enriched yeast sample in terms of its isotopic distribution, total selenium concentration and selenomethionine as well as proteins with molecular weight of approximately 12 kDa.
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Svensson, Richard. "Determination of Al, Ca, Fe, K, Mg, P and Na in soil by ICP-AES and method validation of the AL-method." Thesis, Uppsala universitet, Institutionen för kemi - BMC, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-325279.
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Elis, [forename not supplied], and elis cen@student rmit edu au. "The optimisation of a method for total selenium analysis and application to cereal grain foods." RMIT University. Applied Sciences, 2008. http://adt.lib.rmit.edu.au/adt/public/adt-VIT20081128.143142.
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Cereal based foods, including breakfast cereals and Asian noodles are potentially good sources of selenium. Although these are major foods consumed globally, their contribution to dietary intakes of selenium is unclear. In addition, there has been very limited research into the effect of processing steps on the analysis and apparent retention of selenium. The low levels typically present in foods and the presence of multiple chemical forms of the element provide significant analytical challenges to research in this area. Therefore, the aims of this study were firstly to evaluate and validate procedures for extraction and measurement of selenium in wheat flour. Secondly, the procedure has been applied to analysis of selenium in cereal foods. The methods employed were firstly validated using wheat-based reference materials and then samples of various breakfast cereals as well as different styles of Asian noodles were analysed. Selenium was extracted using closed- v essels by microwave digestion with a mixture of nitric acid and hydrogen peroxide, followed by determination through Inductively Coupled Plasma - Mass Spectrometry (ICP-MS). The optimum conditions for selenium determination in cereal based foods involved the digestion of 0.1 g samples using 1 mL of nitric acid and 1 mL of hydrogen peroxide. The addition of 1% (v/v) methanol was found to enhance the sensitivity of the ICP-MS system. Two particular isotopes of selenium (77 and 82) could be effectively employed in the analysis and there was no significant decrease in total selenium in the digested extracts during storage for up to twelve days under refrigeration and room temperature conditions. Good precision levels were obtained and the total selenium levels in the breakfast cereal samples ranged from 0.059 to 0.378 µg/g. For white salted noodles the values varied between 0.057 and 0.712 µg/g, for yellow alkaline noodles, 0.109 to 0.265 µg/g and 0.077 to 0.284 µg/g for fried instant noodles. There was no appar ent change observed in total selenium during the processing of fried instant noodles, indicating the effectiveness of the extraction method developed here. It is concluded that microwave digestion is an effective approach to sample extraction, the procedures validated in this study are suitable for cereal grain foods and that there is considerable variation in the selenium contents of breakfast cereal and Asian noodle products.
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Disch, Benoit A. "Novel method for the determination of radionuclides and their precursors in concrete using LA-ICP-MS." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/13692.
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During the decommissioning of nuclear facilities, a range of materials are generated and need careful characterisation in order to segregate them into their appropriate waste stream. The procedures involved demand significant time and investments to accurately determine the radionuclide inventory necessary to proceed. Methodology requires sampling, homogenisation, dissolution and sometimes a separation step to measure radionuclides using their decay properties. The approach proposed here is to spatially resolve the distribution of major and trace elements in concretes, and by inference important neutron activation-induced radionuclides, using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The technique offers the possibility of an onsite sampling tool for the different concrete constituents such as aggregates and sand/cement mixes at the micron scale, with typical detection limits in the ng.g-1 range for most elements. Several shielding concrete samples from Windscale (Cumbria) and CONSORT research reactor hosted by Imperial College (Silwood Park campus) are investigated. Initial work focussed on the identification and main chemistry of the aggregate types involved, using a set of chemical characteristics to fingerprint the ablated phases. Subsequently, available and manufactured calibration materials are evaluated for direct quantification purposes, together with wet chemistry reference values obtained for each concrete constituent for validation. Typical chemistry can thereafter be linked to each phase and build the overall bulk information. Finally, the potential to measure 3H directly using ICP-MS is investigated. This theoretical approach describes the conventional analysis methods and problems with ICP-MS analysis and considers several technological advances from the original instrumentation to overcome these, including the latest instrument available and figures of merit based on practical data.
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Kinahan, Meghan. "Determination of platinum group elements in environmental samples using in-line mini-column pre-concentration and separation coupled to inductively coupled plasma mass spectrometry." Thesis, Kingston, Ont. : [s.n.], 2008. http://hdl.handle.net/1974/1021.
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SANTOS, ROBINSON A. dos. "Otimização da metodologia de preparação do cristal de brometo de tálio para sua aplicação como detector de radiação." reponame:Repositório Institucional do IPEN, 2012. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10085.
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Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
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Rajendran, Kaliaperumal. "The development and application of an analytical method for the determination of technetium-99 in the aquatic environment." Thesis, University of Glasgow, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.321830.
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Axelsson, Mikael D. "Multi-element analysis of environmental samples using LA-ICP-MS : method developments with emphasis on calibration strategies /." Luleå : Univ, 2002. http://epubl.luth.se/1402-1544/2002/34/index.html.
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Engström, Emma. "Fractionation of the stable silicon isotopes studied using MC-ICP-MS : analytical method developments and applications in geochemistry /." Luleå : Department of Chemical Engineering and Geosciences, Division of Geosciences, Luleå University of Technology, 2009. http://pure.ltu.se/ws/fbspretrieve/3522867.
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Haas, Karsten. "Evaluation of GC-ICP-MS method for the determination of volatile metal(loid) compounds in environmental gas samples." Thesis, University of Aberdeen, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430377.
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The aim of this study is to perform multielemental determinations of volatile organometal(loid) compounds (VOMs) in environmental gases such as landfill gas and sewage sludge fermentation gases. The analytical method focuses on the on-line coupling of capillary GC with ICP-TOF-MS and provide excellent separation as well as sensitive element selective detection. It involves a cryotrapping step for these (VOMs) such as hydrides, methylated and permethylated species of e.g. As, Sb, Sn, Bi, Hg, Pb etc. In-house standards were generated in Tedlar® bags and a classical external calibration (R2 >0.99) was applied. The precision of injections was good (RSD = 3-11%, N=10) and the standards were reproducibly generated (RSD = 3.20%, N=3). A total number of 4 landfill sites and 5 sewage sludge treatment sites were sampled. One landfill site contained 15 different Sn-compounds, 5 species of which had a concentration of more than 13 ng/l, with a maximum concentration of 1050 ng/l for Me4Sn. Overall, the concentration range of most of the Sn-compounds was 0,01-0,5 ng/l and some unknown species could also be identified. In addition, the permethylated species of As, Se, Sb and Bi could be detected in the range of 0,01 – 117 ng/l. Although their concentration was usually relatively low (at 0,01 – 0,09 ng/l), the variety of volatile Sn-compounds in the sludge fermentation gas samples was quite astonishing. Me3Bi and Me3Sb were the dominant species in the sludge fermentation gases at concentrations of up to 42 ng/l.
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Vranjkovina, Amir. "Spectroscopic evaluation of stability and homogeneity of formulated lubricant." Thesis, KTH, Skolan för kemi, bioteknologi och hälsa (CBH), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-259699.
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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 (< 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 (<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.
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Ežerinskis, Žilvinas. "Study and reduction of the matrix effects in analytical ICP mass spectrometric measurements." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20111227_092301-36142.
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Measurements of the signals proportional to the radiation intensities or the number densities of the charged particles in argon ICP plasma are between the most popular methods of analysis of low concentrations of elements. But the relationships between the signals and the quantity of element in the sample are very complicated, depend on many physical phenomena and chemical reactions and must be calibrated by application of the reference materials. The accuracy of analysis depends on the level of agreement between the compositions of the RM matrices and the sample. As the exact matching is not possible the signal formation in the argon plasma and the effects of matrices on the analytical results should be studied. A method of calibration of the dependence of the sensitivity of the mass spectrometer on the ion masses and methods to determine the electron density and temperature from the mass spectrometric measurement data were proposed. Those aid estimation of the ion signals for analysis and assessment of the measurement uncertainty. The largest matrix effects usually are due to easy to ionize elements. The results show that those elements in argon plasma, depending on the ionization potentials and the structure of the atomic energy levels, differ in possibilities to increase the temperature, the temperature and density gradients, deviation from the local thermodynamic equilibrium, take part in charge transfer reaction between doubly ionized ions and argon atoms. The phenomena... [to full text]Mažos elementų koncentracijos šiuo metu dažniausiai yra nustatomos fizikiniais metodais. Dažnai matuojamas spinduliuotės stipris arba elektringų dalelių skaičius. Tačiau ryšys tarp signalo dydžio ir elemento atomų kiekio yra labai sudėtingas daugelio fizikinių (garavimo ar dulkėjimo, disociacijos, atomų sužadinimo bei jonizacijos, srautų ir kt.) reiškinių bei cheminių reakcijų rezultatas. Jų išeiga kol kas pakankamu tikslumu negali būti numatyta. Todėl tokie matavimai yra tik santykiniai, t.y. jie kalibruojami etaloninėmis medžiagomis. Kalibravimo tikslumas priklauso nuo to kiek bendroji etaloninės medžiagos sudėtis artima tiriamajai medžiagai. Tai įmanoma padaryti tik tam tikru artutinumu. Todėl darbe tiriamos signalo formavimosi sąlygos indukcinėje argono plazmoje ir paskirų paveikiųjų elementų bei bendros bandinio sudėties įtaka bandinių analizinių masių spektrometrinių matavimų rezultatams. Pasiūlytas būdas masių spektrometro jautrio priklausomybei nuo jono masės kalibruoti bei būdai elektronų temperatūrai ir koncentracijai nustatyti iš jonų spektrometrinių matavimų. Tai leidžia įvertinti jonų signalus santykinei pusiaukiekybinei analizei, padeda nustatant matavimų neapibrėžtis. Nustatyta, kad labiausiai analizinį signalą argono plazmos šaltiniuose įtakojantys lengvai jonizuojami elementai, priklausomai nuo jų jonizacijos potencialų ir atominių energijos lygmenų išsidėstymo, gali padidinti plazmos temperatūrą ir gradientus bei nukrypimus nuo dalinės termodinaminės... [toliau žr. visą tekstą]
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Clutterbuck, Amberlie A. "Method Development for the Collection and Instrumental Analysis of Harmful Compounds in Mainstream Hookah Smoke." University of Cincinnati / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1491227953201259.
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Mortensen, Magnus. "Method for quantification of Ca, Cu, Fe, Mg, Sr and Zn in low concentrated whole blood samples using ICP-AES." Thesis, Uppsala universitet, Institutionen för kemi - BMC, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-386069.
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Cotta, Aloísio José Bueno. "Determinação de elementos-traço em águas e rochas por ICP-MS quadrupolar com cela de colisão." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/286784.
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Orientador: Jacinta EnzweilerTese (doutorado) - Universidade Estadual de Campinas, Instituto de Geociências
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Resumo: A espectrometria de massas com plasma indutivamente acoplado (ICP-MS) possibilita determinações multielementares rápidas e com baixos limites de detecção numa variedade de matrizes, dentre elas as geológicas. Neste estudo, métodos comparativos utilizando um ICP-MS quadrupolar equipado com cela de colisão (CC) foram estabelecidos para determinar amplos conjuntos de elementos-traços em águas e em rochas. A aplicabilidade e as limitações da CC para atenuar interferências poliatômicas sobre os isótopos empregados foram amplamente investigadas. Em condições ótimas, muitas interferências puderam ser eliminadas ou significativamente atenuadas, o que tornou os métodos menos dependentes de correções matemáticas. Para a análise de rochas, técnicas clássicas de dissolução envolvendo misturas ácidas, como HF/HNO3, foram utilizadas e um novo procedimento com equipamento que possibilita efetuar a digestão sob pressão de até 13 MPa é proposto. Nesse caso, a precipitação de AlF3, o qual retém alguns elementos-traço, principalmente Co, Sr, Ba e Pb, foi o maior obstáculo à recuperação quantitativa dos analitos. A formação de AlF3 foi evitada com a adição de Mg à porção teste e com o controle da temperatura de digestão. A decomposição por sinterização com peróxido de sódio foi também investigada e verificou-se que a inclusão de uma etapa de aquecimento da dispersão resultante da dissolução do sinterizado em água, antes da separação do precipitado de hidróxidos de Fe e Ti, o qual retém os elementos-traço, auxilia na coprecipitação de Ni, Zr, Nb, Cd, Sn, Sb, Hf, Pb e Th e permite acrescentá-los à lista de elementos determináveis. Os métodos foram validados pela análise de um conjunto de materiais de referência (MR), alguns deles certificados. Os resultados obtidos demonstraram que os métodos desenvolvidos para águas e rochas apresentaram tendência e coeficientes de variação menores que 5% para a maior parte dos mensurandos. Os resultados obtidos para os MR certificados de rochas, BRP-1 e OU-6, foram utilizados para calcular a incerteza do método ao nível aproximado de confiança de 95%. A técnica de diluição isotópica foi aplicada para determinar Cr, Ni, Cu, Zn, Sr e Sn em alguns MR de rochas em uso e em candidatos a MR, com o objetivo de estabelecer o método e contribuir com novos valores para esses MR. As incertezas de todas as etapas do procedimento foram estimadas. Os resultados obtidos evidenciam que o valor certificado de Cr em BRP-1 deveria ser revisto e confirmam a necessidade do estabelecimento da rastreabilidade metrológica durante a certificação de MR.
Abstract: Inductively coupled plasma mass spectrometry (ICP-MS) is suited for fast multi-trace element determinations with low detection limits in a variety of matrices, including geological samples. In this study we established comparative analytical methods for the determination of an expressive number of trace elements in water and rock samples using an ICP-MS equipped with collision cell (CC). The applicability and limitations of CC for polyatomic interference attenuation over the isotopes used were widely investigated. Under optimized conditions, many interferences were eliminated or significantly attenuated, so these methods depend less on mathematical corrections. For rock analyses, classical multi-acid decomposition techniques, with mixtures like HF/HNO3, were used, and a new procedure with equipment that allows digestion at 13 MPa is proposed. In this case, the precipitation of AlF3, which retains some trace elements like Co, Sr, Ba and Pb preferentially, was the major drawback in achieving quantitative recoveries. The formation of AlF3 was inhibited by adding Mg to the test portion and controlling the temperature of digestion. Sample decomposition by sintering with sodium peroxide was also tested and was demonstrated that including a heating step of the sinter dispersion obtained after dissolution in water and before the separation of the precipitated Fe and Ti hydroxides, which retain many trace elements, helps to achieve a quantitative co-precipiation of Ni, Zr, Nb, Cd, Sn, Sb, Hf, Pb and Th and allows to include them to the list of determinable elements. The methods were validated by analysis of a set of reference materials (RM) some of them certified. Relative standard deviations and bias of the results were less than 5% for most of the measurands. The results obtained for the certified RM BRP-1 and OU-6 were used to calculate the measurement uncertainty at the approximate 95% confidence interval. The isotope dilution technique was applied to determine Cr, Ni, Cu, Zn, Sr and Sn in some geochemical RM in use and in candidate RM, with the objective of establishing the method to contribute with new values for the analysed RM. The uncertainties of the whole analytical procedure were estimated. The results obtained show that the certified value of Cr in BRP-1 should be reviewed and confirm the need of establishing the metrological traceability during the certification of RM.
Doutorado
Geologia e Recursos Naturais
Doutor em Ciências
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Nguyen, Thu-Hoai. "Abiotic methylation of inorganic mercury in natural waters : Method development for determination of monomethylmercury in natural waters by GC-ICP-MS." Thesis, Umeå universitet, Kemiska institutionen, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-150627.
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Kang, Bong-Gu, Inga Focke, Wolfgang Brameshuber, and Wilhelm Benning. "Quantitative räumliche Auswertung der Mikrostruktur eines in Beton eingebetteten Multifilamentgarns." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2009. http://nbn-resolving.de/urn:nbn:de:bsz:14-ds-1244046141163-19660.
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Zur detaillierten Beschreibung des Lastabtragverhaltens textiler Bewehrung im Beton ist es erforderlich, das Penetrationsverhalten der Betonmatrix in die stark heterogene Garnstruktur zu beschreiben. Zur Charakterisierung der Mikrostruktur im Querschnitt wurde eine Bildanalysemethode entwickelt, um die Verbundsituation der einzelnen Filamente quantitativ auswerten zu können. Um eine räumliche Beschreibung der Verbundsituation zu erreichen, wurde die Strategie verfolgt, aus aufeinander folgenden Schichtaufnahmen mittels Rasterelektronenmikroskopie eine räumliche Struktur abzuleiten. Hierzu wurden zum einen die experimentelle Vorgehensweise erarbeitet und zum anderen ein Ansatz für die Zuordnung der Filamente zwischen den einzelnen Querschnitten entwickelt.
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Michalec, Adam. "Studium vlivu způsobu chovu slepic na obsah vybraných chemických složek vajec." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2018. http://www.nusl.cz/ntk/nusl-376839.
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This diploma thesis is focused on the analysis of egg yolks and egg whites from chickens raised with different breeding methods in the Czech Republic using three analytical methods. The Kjeldahl method was used to determine the proteins, the Soxhlet method was used to determine the lipids and ICP-OES was used for elemental analysis. The theoretical part describes the history of chicken breeding, marking and distribution of eggs and composition of eggs based on various aspects. The main point was the separation of egg yolk and egg white and the subsequent description on the chemical and physiological level. Principle of used methods is also described. The experimental part deals with the preparation of samples, calibration samples and process analysis. All the results of analysed substances are summarized, statistically evaluated and compared with the other literature. For this analysis were used eleven different types of eggs from the Czech Republic from six different categories.
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Nunes, Juliana Andrade. "Desenvolvimento de método para determinação de Ag, As, Cd, Co, Mn, Ni, Pb e Se em sangue por espectrometria de massas com fonte de plasma acoplado indutivamente (ICP-MS) utilizando diluição das amostras em meio alcalino." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/60/60134/tde-25082009-143632/.
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A técnica analítica mais utilizada para o monitoramento de exposição a metais tóxicos ou para avaliação de deficiência a elementos essenciais é a espectrometria de absorção atômica chama (FAAS) ou com forno de grafite (GF AAS). Entretanto, cada vez mais os laboratórios de pesquisa na área clínica estão mudando seus métodos de análise, baseados nestas técnicas, para a utilização da espectrometria de massas com plasma acoplado (ICP-MS). Isso vem acontecendo porque o ICP-MS permite a determinação de elementos químicos, em diversas matrizes, numa ampla faixa de concentração (ng L-1 a mg L-1), além de possibilitar alta rapidez de análise, capacidade multielementar e limites de detecção menores que outras técnicas analíticas. Uma das principais características do método a ser utilizado para a análise de elementos químicos em rotina por ICP-MS é que ele seja rápido, com o mínimo de manipulação da amostra. Neste sentido, métodos que propõem a análise direta de amostra são mais atrativos. Todavia, ainda é limitado o número de métodos que propõem análise direta de fluidos biológicos por ICP-MS. Neste sentido, o presente trabalho teve como objetivo o desenvolvimento de um método para análise direta de sangue por ICP-MS para determinação de Ag, As, Cd, Co, Mn, Ni, Pb e Se. Para isso, amostras de sangue (200 µL) foram misturadas com 500 µL de hidróxido de tetrametilamônio (TMAH) (10% v/v) e incubadas por 10 minutos. Posteriormente, a solução resultante foi diluída para 10 mL com uma solução contendo 0,05% m/v EDTA; 0,005% v/v Triton® X-100. Em seguida, as amostras foram analisadas diretamente por ICP-MS (ELAN DRC II). Ródio (Rh) foi usado como padrão interno e a calibração das amostras foi feita por meio de ajuste de matriz com sangue base ovino. Os limites de detecção (LD) do método foram de 0,008; 0,02; 0,004; 0,009; 0,003; 0,09; 0,04; 0,1 µg L-1 para Ag, As, Cd, Co, Mn, Ni, Pb and Se, respectivamente. A validação dos resultados foi realizada com análise de um material de referência de sangue do Programa de Proficiência do Institut National de Santé Publique du Quebec, no Canadá. Validação adicional foi obtida pela comparação dos resultados obtidos pela análise de 20 amostras de sangue pelo método proposto e pela técnica de GF AAS. O método foi também comparado a outros dois existentes na literatura e comumente utilizados em laboratórios dos Estados Unidos e Suécia, apresentando limites de detecção comparáveis ou melhores e melhores exatidão e precisão.The most used analytical technique for monitoring the exposure to toxic metals or for the assessment of the deficiency of essentials elements is the atomic absorption spectrometry with flame (FAAS) or graphite furnace (GF AAS). However, more and more clinical laboratories are changing their methods of analysis, based on this technique, to methods using inductively coupled plasma-mass spectrometry (ICP-MS). It occurs because ICP-MS allows the determination of chemical elements in various types of samples, at concentrations in a wide linear range (ng L-1 to mg L-1), providing high-throughput analysis with multielemental capability with lower detection limits. However, for routine porpuses the method of choice must be fast with minimal sample manipulation.On the other hand, the number of methods proposing direct introduction of biological fluids to the ICP-MS are still limited. This work aimed the development of a method for the direct analysis of blood samples by ICP-MS for the determination of Ag, As, Cd, Co, Mn, Ni, Pb and Se. For this, blood samples (200 L) were mixed with 500 L of tetramethylammonium hydroxide (TMAH) (10% v/v) and left at room temperature during 10 minutes. Subsequently, the resulting solution was diluted to 10 mL with a solution containing 0.05% m/v EDTA + 0005% v / v Triton ® X-100. Thus the samples were analyzed directly by ICP-MS (ELAN DRC II). Rhodium (Rh) was used as internal standard with matrix matching calibration. The method detection limits were: 0.008, 0.02, 0.004, 0.009, 0.003, 0.09, 0.04, 0.1 µg L-1 for Ag, As, Cd, Co, Mn, Ni , Pb, and Se respectively. Method validation was acquired with the analysis of blood reference material provided by the Institut National de Santé Publique du Quebec, Canada. Furthermore, for additional validation 20 ordinary blood samples were analyzed by the proposed method and by GF AAS. The method was also compared with two existing methods in the literature and commonly used in laboratories in the United States and Sweden where comparable or better detection limits and better accuracy and precision were obtained.
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Troalen, Lore Gertrud. "Historic dye analysis : method development and new applications in cultural heritage." Thesis, University of Edinburgh, 2013. http://hdl.handle.net/1842/11717.
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A review of the main natural dyes (particularly yellow flavonoids and red anthraquinones) and proteinaceous substrates used in Historical Tapestries and North American porcupine quill work was undertaken, and is summarised in Chapter 1. The analysis of natural dyes which have been used on museum artefacts other than textiles has received little systematic study, particularly those of non-European origin. In this research, the use of Ultra Performance Liquid Chromatography (UPLC) for study of natural dyes found on historical textiles and ethnographical objects decorated with porcupine quill work is explored; this required a transfer of existing analytical protocols and methodology. The advantages of using Ultra Performance Liquid Chromatography (UPLC) was evaluated through a method development based on the separation and quantification of ten flavonoid and anthraquinone dyes as described in Chapter 2. These methods were then applied to the characterisation of the dye sources found on a group of sixteenth century historical tapestries which form an important part of the Burrell Collection in Glasgow and are believed to have been manufactured in an English workshop (Chapter 3) and also to the analysis of some late nineteenth century North American porcupine quill work from a collection owned by National Museums Scotland (Chapter 5); allowing exciting conclusions to be drawn in each case about the range of dyestuffs used in their manufacture. The second aim of this research was the development of methodology for the non-invasive quantification of metal ion residues on porcupine quill substrates. This was achieved through a comparative study of reference porcupine quills prepared in-house with dyebaths containing a range of metal ion concentrations (copper and tin). The concentration of metal ions sorbed by the porcupine quills was then quantified with Inductively Coupled Plasma (ICP) coupled to Optical Emission Spectrometry (OES) and non-invasive Particle Induced X-Ray Emission analysis (PIXE) coupled with Rutherford Backscattering Spectrometry (RBS) as described in Chapter 4. The responses provided by the different methods were compared and they were then applied to the study of micro-samples collected from mid-nineteenth century Northern Athapaskan porcupine quill work. Unexpectedly, the use of UPLC analysis and RBS-PIXE analysis allowed the characterisation of traded European natural dyes used with metallic mordants (copper and tin) on these samples, highlighting how European contact impacted on traditional Athapaskan porcupine quill work in the late nineteenth century (Chapter 5).
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Fähnrichová, Nikola. "Analýza vybraných odrůd českého česneku." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2018. http://www.nusl.cz/ntk/nusl-376830.
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This master thesis deals with analysis of Czech garlic varieties in comparison with two varieties from abroad. Alliin and carbohydrates were determined by high performance liquid chromatography with diode-array detector or evaporative light scattering detector. Crude proteins were calculated from total content of nitrogen that was determinated by Kjeldahl method. Elementary analysis was performed by inductively coupled plasma optical emission spectrometry. In theoretical part of this thesis is describes botanical characterization and cultivation of garlic, chemical composition of garlic, especially groups of substances which were analysed in this thesis. Principle of used methods is described too. The experimental part of this work deals with sample and calibration solution preparation and process of analysis. Obtained results from analysed substances are summarized in the tables, discussed and compared with results of analysis of other authors. Between Czech and Spanish/Chinese garlic are slight differences. Garlics contain 24,66 g/kg dry weight of alliin. Content of crude proteins in Czech garlic is comparable to Chinese garlic but the Spanish garlic has just half of amount crude proteins. Elementary analysis also includes significant differences. Czech varieties contain higher amount of phosphorus, iron and zinc. On the contrary, content of potassium in foreign garlic is higher than in Czech Republic and the analysed amount is 15 g/kg dry weight.
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Benros, Santos Lopes Silvania. "Integrated CFD Model for Nanoparticle Production in Inductively Coupled Plasma Reactor: Implementation and Application." Doctoral thesis, Universite Libre de Bruxelles, 2016. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/230486.
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Nanoparticles represent a very exciting new area of research. Their small size, ranging from several nanometers to tens of nanometers, is responsible for many changes in the structural, thermal, electromagnetic, optical and mechanical properties in comparison with the bulk solid of the same materials. However, promoting the use of such material requires well-controlled synthesis techniques to be developed. Inductively coupled thermal plasma (ICTP) reactors have been shown to offer unique advantages over other synthesis methods. The purpose of this thesis is to develop a numerical model to assist the design of an ICTP reactor for the efficient and controlled production of nanoparticles at industrial scale. The complete model describes the evaporation of the micron-sized precursor particles in the plasma flow and the subsequent formation of the nanoparticles in the quenching reactor. The plasma flow is described by a coupled system of the fluid mechanics equations of continuity, momentum, and energy with the vector potential formulation of Maxwell's equations. The solid particles precursors are treated following a Lagrangian approach, taking into account the vapor production field in the plasma flow. An Eulerian model based on the method of moments with interpolative closure is used to describe the formation of nanoparticles by simultaneous nucleation and growth by condensation and coagulation. The coupled plasma torch, particle evaporation and nanoparticle formation models are implemented in 2D and 3D configurations, using the OpenFoam source code. The results show that the effects of the particle evaporation on the temperature field are substantial, even for low particle mass loading. The associated vapor concentration which enters in the reactor has then a direct influence on the formation of nanoparticles. The effects of the plasma torch parameters and the quenching configuration (quench type, position, injection angle and cooling rate) on the contribution of the different formation mechanisms and on the generated particle's size and distribution are studied in both 2D axi-symmetric and 3D geometries. The quench mechanism strongly affects the temperature and the vapor concentration in the reactor, and consequently has an impact on the final particle size distribution. It is shown that the size of the nanoparticles obtained for different quenching conditions is not only a consequence of the cooling rate but also of the trajectories of the vapor and the generated particles imposed by quenching gas. The results have also demonstrated that the predicted particle are smaller and more sensitive to the modifications of the quenching condition when quenching at high temperature. The sensitivity of the complete model to the physical properties of the vapor (vapor pressure and surface tension) is also investigated, in order to identify their effect on the final particle size. The results obtained provide an insight into the phenomena involved during the production of nanoparticles and enable the improvement of ICTP rectors design and nanoparticles synthesis process.Doctorat en Sciences de l'ingénieur et technologie
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Yang, Kai. "Fabrication and characterization of silicon nanowires for devices applications compatible with low temperature (≤300 ˚C) flexible substrates." Thesis, Rennes 1, 2019. http://www.theses.fr/2019REN1S123.
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La fabrication et la caractérisation de nanofils de silicium à basse température (≤300 °C) a été menée suivant deux approches: par la méthode des espaceurs et par la méthode de croissance Solide Liquide Solide (SLS). La synthèse des nanofils de silicium a été étudiée à l'aide de deux technologies de dépôts: le dépôt CVD assisté par plasma (PECVD) et le dépôt à couplage inductif (ICP CVD). Les études ont démontré la faisabilité des nanofils de silicium par le procédé ICP-CVD. De plus, les propriétés d'isolation électrique des couches de SiO2 et la fabrication de transistors à effet de champ à couche mince ont été démontrées à l'aide de la technologie de dépôt plasma ICP. Par ailleurs, des nanofils de silicium ont été synthétisés par le procédé SLS à 250 ° C utilisant l'indium comme catalyseur. La croissance 3D de ces nanofils à partir de substrats de silicium (film mince de silicium monocristallin ou amorphe) a été démontrée. Les nanofils sont obtenus sous plasma d'hydrogène. Des études ont été menées en fonction de l'épaisseur de l'indium déposé, de la durée et de la température du plasma d'hydrogène. Les résultats originaux obtenus permettent d'envisager la possibilité de fabriquer des dispositifs électroniques à base de ces nanofils de silicium sur des substrats flexibles basse températureThe fabrication and characterization of silicon nanowires (SiNWs) at low temperature (≤300° C) has been focused for two mainstream approaches: spacer method and Solid Liquid Solid method. The feasibility of such silicon nanowires has been explored using two deposition technologies: conventional plasma enhanced deposition (PECVD) and inductively coupled plasma deposition (ICP CVD). The studies demonstrated the feasibility of silicon nanowires using the ICP CVD process. In addition, the electrical insulation properties of SiO2 layers and the fabrication of thin-film field effect transistors were demonstrated using ICP plasma deposition technology. Furthermore, indium catalyzed SLS SiNWs were fabricated for the first time at 250 °C. Synthesis of 3D SiNWs by SLS process from silicon substrates (monocrystalline or amorphous silicon thin film) has been demonstrated. The growth of nanowires is obtained under hydrogen plasma. Studies were conducted based on the thickness of indium deposited, duration and temperature of the hydrogen plasma. All these results were concluded originally and they enable the possibility of fabrication of SiNWs based electronic devices onto low temperature flexible substrates
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CRUZ, ROSANA PETINATTI DA. "DEVELOPMENT OF A METHODOLOGY FOR CORALS AND SPELEOTHEMS DATING USING THE 230-TH/234-U METHOD, THROUGH CHROMATOGRAPHIC SEPARATION AND QUANTIFICATION BY ALPHA SPECTROMETRY AND FIA-ICP-MS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2006. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=8544@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOO presente trabalho aborda as determinações de idades de espeleotemas e corais, usando o método de desequilíbrio da série urânio, mais especificamente, o método de deficiência de filhos daughter deficient DD, em particular o método 230Th/234U. Foram testadas diferentes metodologias empregando separação por extração cromatográfica e quantificação por espectrometria alfa e ICP-MS. Foram testados três procedimentos diferentes: separação em batelada empregando-se colunas com Tri-octil óxido de fosfina (TOPO) em silica- gel e a coluna TRU comercializada pela Eichrom(R), composta de octil-N,N,- isobutil carbamoil óxido de fosfina dissolvido em fosfato de tributila (TBP) e quantificação por espectrometria alfa; separação em batelada com os mesmos sistemas mas quantificação por ICP-MS e separação em linha (flow injection) com cartuchos de TRU e quantificação por ICP-MS. As metodologias desenvolvidas foram validadas empregando-se amostras de referência certificada, IAEA-327 (solo) tendo sido obtidas incertezas de 2% para o método empregando a separação em linha (flow injection) com cartuchos de TRU e quantificação por ICP-MS. As amostras de espeleotema analisadas foram coletadas no Carste de Lagoa Santa, MG, pelo grupo do Prof. Luis Piló (USP) e suas idades variaram de 15,2±2,2 kanos a >350 kanos. Estes valores estão na faixa dos valores encontrados na literatura para amostras de espeleotema coletadas pelo mesmo grupo na mesma região. A amostra de coral, coletada na Bacia de Campos (RJ) era da espécie Lophelia pertusa, foi subdividida segundo suas ramificações (primária, secundária e terciária) e o ramo principal foi datado em 9,4 ± 0,3 kanos.
This paper discusses the age determination of speleothems and corals using Uranium-series- imbalance method, more specifically the daughter deficient method - DD, particularly the 230Th/234U method. Different methodologies were tested using chromatographic extraction separation and quantification by alpha spectrometry and ICP-MS. Three different procedures were tested: batch separation using columns with Tri-N-Octylphosphine Oxide (TOPO) in silica gel and TRU column commercialized by Eichrom(R) composed of octyl-N,N,-isobutyl carbamoylphosphine oxide dissolved in tri-n-butyl phosphate (TBP) and with quantification by alpha spectrometry; batch separation with the same systems, but with quantification by ICP-MS; and flow injection with TRU cartridges and qualification by ICP-MS. The methodologies developed were verified using certified reference samples, IAEA-327 (soil) with 2% imprecision rate for the method using flow injection with TRU cartridges and qualification by ICP-MS. The speleothem samples analyzed were collected at Carste de Lagoa Santa, in the state of Minas Gerais, by Prof. Luis Piló`s (USP) group, and their ages varied from 15,2±2,2 kyears to >350 kyears. These numbers are within the range found in the literature for speleothem samples collected by the same group in the same region. The coral sample, collected at Bacia de Campos (RJ), and from the Lophelia pertusa species, was subdivided according to its ramifications (primary, secondary and tertiary), and the main ramification dated 9,4 ± 0,3 kyears.
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WANDEKOKEN, FLÁVIA GALVÃO. "DEVELOPMENT OF METHOD FOR DETERMINATION OF AS, SB AND SE IN BIODIESEL AND PETROLEUM BY INDUCTIVELY COUPLED PLASMA OPTICAL EMISSION SPECTROMETRY WITH SAMPLE INTRODUCTION BY HYDRIDE GENERATION (HG ICP." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=18416@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCom o aumento da população mundial e o consequente aumento das atividades industriais e consumo de combustíveis, a poluição química vem sendo um grande problema do século XXI. Alternativas que possam minimizar tal problemática são alvos de pesquisas, como o uso de biodiesel, um combustível renovável e menos poluente. Elementos normalmente encontrados em baixas concentrações, como As, Sb e Se, tornam-se tóxicos à saúde humana quando em concentrações acima de certos limites e, por isso, devem ser monitorados em diversas amostras, como combustíveis. Para o Sb, a dose diária aceitável (DDA) é de 6 ug dia(-1) para cada kg de peso corporal e para o Se, valores de concentração acima de 50(-200) ug por dia já são considerados tóxicos. O limite aceitável de As em água potável é de 0,01 mg L(-1) e valores acima de 7,5 x 10-3 ug m(-3) são associados a risco de câncer de pulmão. Esses elementos podem ser constituintes originais do petróleo e seus derivados ou ser adicionados como contaminantes em alguma etapa do refino. No caso do biodiesel, podem estar presentes, decorrente do uso de fertilizantes e pesticidas nas lavouras das plantas que deram origem ao óleo usado na produção desse combustível. Estes elementos podem, durante o processo de combustão dos combustíveis nos motores, ser liberados para a atmosfera. As baixas concentrações em que esses elementos se encontram, normalmente, estão abaixo do limite de detecção de algumas técnicas, como ICP OES com introdução de amostra por nebulização pneumática convencional. Nesse caso, uma alternativa viável é a introdução da amostra por geração de vapor, que proporciona uma melhora significativa na sensibilidade das técnicas analíticas. Este trabalho teve como objetivo determinar simultaneamente As, Sb e Se em amostras de óleo cru e biodiesel, utilizando HG-ICP OES. Para tanto, as amostras tiveram que ser submetidas à decomposição ácida em bloco digestor. Foram estudadas diferentes condições de pré-redução (HCl, tiouréia e ácido ascórbico com KI), avaliadas suas concentrações e tempo de aquecimento. As condições empregando HCl e tiouréia foram as que apresentaram melhores resultados e tiveram seus parâmetros otimizados multivariadamente, assim como os parâmetros da geração de vapor: vazão de amostra, vazão de NaBH4 borohidreto de sódio e vazão do gás de arraste. Estabelecidas as melhores condições para análise e respeitando-se as limitações da técnica, o método foi avaliado através da análise de material certificado de óleo combustível residual (NIST 1634c), biodiesel de óleo de soja (NIST 2772) e biodiesel de gordura animal (NIST 2773), empregando-se as duas condições de pré-redução citadas. Nesse caso, o uso de HCl como pré-redutor foi mais eficiente, com recuperações entre 90% e 99% para os 3 analitos. Já a pré-redução com tiouréia foi eficiente só para Sb, com recuperação em torno de 104%, enquanto as recuperações para As e Se foram entre 57% e 29%. Sendo assim, para o método proposto empregou-se HCl como pré-redutor. As condições otimizadas para a geração e empregadas para as análises das amostras foram: vazão da amostra, 3,0 mL min(-1); vazão do NaBH4 1,5 mL min(-1); vazão de gás de arraste 0,8 L min(-1) e concentração do HCl 8 mol L(-1). Um estudo para verificar uma possível interferência de Ni nas condições otimizadas para a geração de vapor revelou que este interferente não prejudica as determinações de As, Sb e Se quando se emprega HCl 8 mol L(-1). Sendo assim, analisaram-se as amostras de óleo cru e biodiesel nas condições previamente otimizadas. Foi detectada a presença de apenas As e Se nas amostras de óleo cru enquanto as amostras de biodiesel não apresentaram concentrações de As, Sb e Se acima dos LODs obtidos. Embora as recuperação para as adições de Sb nas amostras de biodiesel e óleo cru tenham ficado dentro de um intervalo relativamente grande, entre 72% e 111%, evidenci
With the increasing world population and the consequent increasing in industrial activities and fuel consumption, chemical pollution has been a major problem of the XXI century. Alternatives that can minimize such problems are targets of researches, such as the use of biodiesel, a renewable and less polluting fuel. Elements usually found in low concentrations, such as As, Sb and Se, become toxic to human health when in concentrations above certain limits and, therefore, should be monitored in several samples, such as fuels. For Sb the acceptable daily intake (ADI) is 6 mg day(-1) for each kg of body weight and, for Se, concentrations above 50-200 mg per day are considered toxic. The As acceptable limit in drinking water is 0.01 mg L(-1) and values above 7.5 x 10-3 g m(-3) are associated to risk of lung cancer. These elements may be original constituents of petroleum and its derivatives or be added as contaminants at some step of the refining process. In the case of biodiesel, these elements can be present due to the use of fertilizers and pesticides in the crops that produce the oil used in the biodiesel production. These elements can be released to the atmosphere during the fuel burning in the motor. The usually low concentrations of these elements can be below the detection limit of some techniques, such as ICP OES with sample introduction by standard pneumatic nebulization. In these case, the vapor generation is an interesting alternative for sample introduction, since it provides a significant improvement in the sensitivity of the analytical technique. This study aimed to simultaneously determine As, Sb and Se in crude oil and biodiesel samples, using HG-ICP OES. For that, samples had to be subjected to acid decomposition in a block digester, thus allowing calibration with inorganic standard solutions. Different pre-reduction conditions were studied (HCl, thiourea and ascorbic acid with KI), being evaluated the reagents concentrations and heating time. The conditions using HCl and thiourea showed the best results and had their parameters multivariate optimized, as well as the parameters of the vapor generation: sample, sodium borohydride and carrier gas flow rates. Established the best conditions for analysis and respecting the limitations of the technique, the method was validated by analysis of a residual fuel oil certified material (NIST 1634c), biodiesel from soybean oil (NIST 2772) and biodiesel from animal fat (NIST 2773), using the two cited pre-reduction conditions. In this case, the use of HCl as pre-reducer was more efficient, with recoveries between 90% and 99% for the three analytes. Pre-reduction with thiourea was effective only for Sb, with recovery around 104%, while the recoveries for As and Se were between 57% and 29%. Thus, HCl was employed as the pre-reducer in the proposed method. The optimized conditions for the generation and used for the analysis of the samples were: sample flow rate, 3.0 mL min(-1); NaBH4 flow rate, 1.5 mL min(-1); carrier gas flow rate, 0.8 L min(-1) and concentration of HCl, 8 mol L(-1). A study to verify a possible interference of Ni under the optimized conditions for vapor generation revealed that this interference does not affect the determination of As, Sb and Se when employing HCl 8 mol L(-1). Therefore, crude oil and biodiesel samples were analyzed at the previously optimized conditions. Only As and Se were detected in crude oil samples, while the concentrations of these analytes in the biodiesel samples were always lower than the obtained LODs. Although, the recovery for the Sb additions in biodiesel and crude oil samples were in a large range, between 72% and 111%, indicating that HCl is not the most efficient pre-reducer for this element, it can be said that, for multielemental analysis whose objective is to evaluate the presence of this element or a possible contamination by it, this prereducer can be employed.
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Ežerinskis, Žilvinas. "Bandinio sudėties įtakos elementų koncentracijų nustatymui indukcinės plazmos masių spektrometrijoje tyrimas." Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20111227_092410-62079.
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Mažos elementų koncentracijos šiuo metu dažniausiai yra nustatomos fizikiniais metodais. Dažnai matuojamas spinduliuotės stipris arba elektringų dalelių skaičius. Tačiau ryšys tarp signalo dydžio ir elemento atomų kiekio yra labai sudėtingas daugelio fizikinių (garavimo ar dulkėjimo, disociacijos, atomų sužadinimo bei jonizacijos, srautų ir kt.) reiškinių bei cheminių reakcijų rezultatas. Jų išeiga kol kas pakankamu tikslumu negali būti numatyta. Todėl tokie matavimai yra tik santykiniai, t.y. jie kalibruojami etaloninėmis medžiagomis. Kalibravimo tikslumas priklauso nuo to kiek bendroji etaloninės medžiagos sudėtis artima tiriamajai medžiagai. Tai įmanoma padaryti tik tam tikru artutinumu. Todėl darbe tiriamos signalo formavimosi sąlygos indukcinėje argono plazmoje ir paskirų paveikiųjų elementų bei bendros bandinio sudėties įtaka bandinių analizinių masių spektrometrinių matavimų rezultatams. Pasiūlytas būdas masių spektrometro jautrio priklausomybei nuo jono masės kalibruoti bei būdai elektronų temperatūrai ir koncentracijai nustatyti iš jonų spektrometrinių matavimų. Tai leidžia įvertinti jonų signalus santykinei pusiaukiekybinei analizei, padeda nustatant matavimų neapibrėžtis. Nustatyta, kad labiausiai analizinį signalą argono plazmos šaltiniuose įtakojantys lengvai jonizuojami elementai, priklausomai nuo jų jonizacijos potencialų ir atominių energijos lygmenų išsidėstymo, gali padidinti plazmos temperatūrą ir gradientus bei nukrypimus nuo dalinės termodinaminės... [toliau žr. visą tekstą]Measurements of the signals proportional to the radiation intensities or the number densities of the charged particles in argon ICP plasma are between the most popular methods of analysis of low concentrations of elements. But the relationships between the signals and the quantity of element in the sample are very complicated, depend on many physical phenomena and chemical reactions and must be calibrated by application of the reference materials. The accuracy of analysis depends on the level of agreement between the compositions of the RM matrices and the sample. As the exact matching is not possible the signal formation in the argon plasma and the effects of matrices on the analytical results should be studied. A method of calibration of the dependence of the sensitivity of the mass spectrometer on the ion masses and methods to determine the electron density and temperature from the mass spectrometric measurement data were proposed. Those aid estimation of the ion signals for analysis and assessment of the measurement uncertainty. The largest matrix effects usually are due to easy to ionize elements. The results show that those elements in argon plasma, depending on the ionization potentials and the structure of the atomic energy levels, differ in possibilities to increase the temperature, the temperature and density gradients, deviation from the local thermodynamic equilibrium, take part in charge transfer reaction between doubly ionized ions and argon atoms. The phenomena... [to full text]
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Bou, Khouzam Rola. "Développement de la méthodologie analytique et surveillance des contaminants dans le panier de la ménagère au Liban." Thesis, Pau, 2011. http://www.theses.fr/2011PAUU3016/document.
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L’objectif du travail est d’évaluer le niveau des contaminants (éléments à l’état de traces et pesticides) dans quatre types de produits alimentaires (pain, fromage, végétaux et fruits) et eau potable considérés parmi les produits les plus consommés par les Libanais suivant l’étude du panier de la ménagère faite en 2006. Une méthode analytique pour l’analyse multi élémentaire a été optimisée pour augmenter la sensibilité et réduire les interférences polyatomiques en utilisant la technique de spectrométrie de masse de haute résolution par plasma induit pour la détermination de 20 éléments mineurs et à l’état de trace afin d’évaluer la valeur nutritive et le niveau de contamination. Pour l’analyse des résidus de pesticides, une méthode analytique a été développé pour la détermination des résidus dans des fromages riches en matières grasses (2-25%). La détermination des résidus de pesticides dans le pain, les végétaux et les fruits a été accomplie suivant la méthode QuEChERS. La surveillance du taux des contaminants a été faite sur des échantillons collectés dans des marches de cinq régions géographiques au Liban durant les saisons humide et sèchesThe objective of this work was to evaluate the level of food contaminants, trace elements and pesticides residues, in four types of commodities bread, white cheese, vegetables and fruits, and drinking water considered as the most consumed by the Lebanese population based on the Food Basket Study on 2006. A multielemental method was optimized in terms of sensitivity and inference elimination by using high resolution sector field inductively coupled plasma mass spectrometry (HR ICP/MS) for the determination of 20 minor and trace elements in the selected foods to assess the nutritional contribution and the level of contamination. For pesticides residues analysis, an analytical method was developed for the quantification of residues in cheese (2-25% fat). Bread, vegetables and fruit were analysed according to the QuEChERS method. For the monitoring study, the samples were collected during two seasons, wet and dry, from five geographical regions in Lebanon
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Pavlechová, Alžbeta. "Elementární analýza sýrů s bílou plísní na povrchu." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2018. http://www.nusl.cz/ntk/nusl-376834.
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This Master's thesis deals with elementary analysis of cheeses with white mold on the surface. Theoretical part describes general characteristics of cheese, classification of cheeses, their nutritional aspects and characteristics of cheeses with white mold on the surface. Large part is focused on description of mineral substances selected for analysis. At the end of the theoretical part, the Kjeldahl method and emission spectrometry with inductively coupled plasma (ICP-OES) were described. Experimental part deals with preparation of samples, approach of analysis and processing of measured results. Eleven samples of cheeses were used for analysis. These samples were from Czech Republic, France and Slovak Republic. Kjeldahl method was used to determine protein contents and ICP-OES was used for elemental analysis. The results were compared to each other and also with results from other studies. Subsequently, they were statistically processed and evaluated in the final part.
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Nelms, Simon. "Flow injection methods of sample introduction for ICP-MS." Thesis, University of Hull, 1997. http://hydra.hull.ac.uk/resources/hull:16060.
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This thesis is concerned with the application offlow injection techniques for on-line sample preparation for inductively coupled plasma mass spectrometry (ICP-MS). A comprehensive introduction to ICP-MS and the various sample introduction methods which have been applied for the technique is presented in Chapter 1. The advantages and disdvantages of the different sample introduction procedures are also considered and discussed. Since ICP-MS is a highly sensitive technique for multi-element analysis at trace levels, there are few methods which can compete with it. The methods which are available are compared with ICP-MS and the advantages and disadvantages of each are discussed in the context of the available literature. The second chapter contains a detailed review of the various reagents which have been used for the selective retention of trace element ions from solutions containing high concentrations of so called 'matrix species' (e.g. Na, Ca, K and Mg). The use of ion-exchange and chelating reagents for trace analyte retention is discussed together with an appraisal of the properties and applications of activated alumina as either a cation or anion exchanger. Most ion-exchange and chelating reagents consist of an organic functional group covalently immobilised onto a support material. The properties of polymer and controlled pore glass support materials are discussed with respect to their behaviour in on-line systems. In Chapter 3, the use of the chelating reagent 8-hydroxyquinoline, covalently immobilised onto controlled pore glass, for on-line preconcentration and matrix separation with ICP-MS detection, is described. A manually operated manifold, directly coupled to the ICP-MS, was developed for this work. The optimisation and analytical performance ofthis manifold is evaluated for Ti4+, V (as VO2+), Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Ag+, Cd2+, Ce3+ and Pb2+ in saline matrix samples and reference materials. Following the development of the manual manifold described in Chapter 3, the construction of an automated preconcentration I matrix separation manifold, using a commercially available liquid handling system is described in Chapter 4. For this work, a novel iminodiacetate chelating reagent, immobilised onto a controlled pore glass support, was used for analyte retention. An initial manifold design is considered, followed by a refined version of the system, which is optimised for the retention of Mn2+, V (as VO2+), Co2+, Ni2+, Cu2+,Zn2+, Ag +, Cd2+, Ce3+, Pb2+ and U (as UO2+). The performance of the novel iminodiacetate chelating material is evaluated for the analysis of two saline reference waters and some saline industrial effluent samples. In Chapter 5, the effects of humic material in the sample on the on-line retention of Ti4+, V (as VO2+ ), Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Ag+, Cd2+, Ce3+, Pb2+ and U (as UO2+) by the iminodiacetate reagent is explored. Humic material, which arises from soil and decaying vegetable matter, exists in fresh and saline waters at concentrations of typically 1 - 50 ppm. This complex material is composed of a number of different organic molecules which contain a variety of functional groups capable of forming chelates with the analytes of interest in the sample. For this reason, interference effects are expected to occur with increasing levels of humic material in the sample. The effect of increasing levels of elements which have an affinity for the iminodiacetate reagent is examined in terms of the retention efficiency of the analytes of interest. In Chapter 6, the subject of microwave digestion for sample preparation is studied. This work initially involves assessing the efficiency of a simple nitric acid digestion for the digestion of selected reference materials in a batch system. The study continues with an evaluation of on-line microwave digestion with off-line analysis using ICP-MS and concludes with an investigation into the feasibility of directly coupling the on-line microwave digestion system to the ICP-MS instrument. Finally, in Chapter 7, the general conclusions to the thesis and suggestions for future research are presented.
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OLIVEIRA, ICIMONE B. de. "Desenvolvimento do cristal semicondutor de brometo de tálio para aplicações como detector de radiação e fotodetector." reponame:Repositório Institucional do IPEN, 2006. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11385.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Tese (Doutoramento)
IPEN/T
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
FAPESP:01/09049-5
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SOUZA, ROSELI MARTINS DE. "DEVELOPMENT OF ANALYTICAL METHODS FOR TRACE ELEMENTS DETERMINATIONS IN OILY AND VISCOUS SAMPLES BY ICP OES E ICP-MS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2007. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=10643@1.
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CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOMétodos de análise para determinação de elementos-traço em amostras oleosas e pastosas são necessários, por exemplo, no caso do petróleo e em suas frações mais pesadas, para os quais os elementos-traço indicam características do tipo do petróleo, correlacionando-o com a localização geográfica da jazida. Além disso, a quantificação destes elementos tem utilidade nas interpretações geoquímicas relacionadas com maturidade térmica, correlação óleo-óleo e migração primária e secundária do óleo e na obtenção de informações que permitem a criação de estratégias para realizar o refino do óleo, prevenindo contaminação dos catalisadores, corrosão de equipamento e potencial dano ambiental. No caso de óleos e gorduras vegetais, a presença destes elementos, mesmo em baixas concentrações ((mi)g g-1), pode acelerar processos oxidativos que geram peróxidos, aldeídos, cetonas, ácidos e epóxidos, que além de causarem a rancidez prematura dos óleos produzem efeitos patológicos no sistema digestivo e potencializam a ação de alguns carcinogênicos. As técnicas espectrométricas baseadas no uso do plasma (ICP OES e ICP-MS) estão entre as mais utilizadas na determinação de elementos- traço nesses tipos de amostra. Porém, os procedimentos de preparação de amostra mais tradicionalmente usados são os que destroem a matriz das amostras, solubilizando-as em ácidos inorgânicos fortes. Neste trabalho, novas estratégias de preparação de amostras de petróleo, óleo diesel, asfaltenos, óleos comestíveis, manteiga e margarina foram desenvolvidas visando à utilização do tradicional procedimento de nebulização de solução para introdução de amostra no plasma. No caso do óleo diesel, a estratégia avaliada foi a de preparação de amostras na forma de emulsão com n-propanol. Nesse caso, um planejamento fatorial indicou que fatores importantes para a determinação de elementos refratários foram tanto a massa de amostra na composição da emulsão (até 25% em massa) quanto a acidificação da emulsão. As amostras de óleo cru, óleos vegetais e gorduras vegetais foram preparadas como microemulsão em n-propanol. Alternativamente, um procedimento de extração assistida por ultra-som foi desenvolvido. A emulsão de óleo cru com n-propanol mostrou ser um bom meio de estabilização dos analitos em solução. No caso da extração ácida assistida por ultra-som para óleo cru, um planejamento fatorial mostrou que os fatores importantes para a determinação de elementos-traço foram, o tempo de aquecimento da amostra, a concentração do ácido nítrico e a exposição ao ultra-som. Para as amostras de óleos e gorduras vegetais, a otimização das proporções de componentes na emulsão com n- propanol proporcionou boa estabilidade e homogeneidade das amostras de óleo de oliva e óleo de soja (6 % em massa de óleo) e para margarina e manteiga (5 % m/m de óleo). Para o método da extração ácida assistida por ultra-som, as condições otimizadas para a preparação da amostra permitiram também a análise por ICP-MS, cujos resultados são discutidos e comparados com os resultados obtidos por ICP OES. Para as amostras de asfaltenos, o procedimento proposto foi o de extração em HNO3 concentrado assistida por ultrasom. Nesse caso, os mesmos parâmetros otimizados para o óleo cru foram usados. Os parâmetros operacionais foram otimizados para obtenção dos parâmetros de mérito, sendo a aplicação dos métodos propostos confirmada por testes de recuperação além de comparação com resultados obtidos com procedimentos tradicionais para esse tipo de amostra. Assim, nessa tese, foram desenvolvidos métodos para a determinação de Cr, Mo, V e Ti em óleo diesel e em óleo combustível, Cd, Co, Cr, Fe, Mn, Mo, Ni, Ti, V e Zn em óleo cru, Fe, Ni e V em asfaltenos. Cd, Co, Cr, Cu, Mn e Ni foram determinados em óleos e gorduras comestív
Analytical methods for the determination of trace elements in oily and viscous samples are necessary, for example, in the case of crude oil and its heavy fractions, where trace elements indicate specific oil characteristics and the geographic location of the natural deposit. Moreover, the quantification of these elements is relevant for geochemical interpretations concerning thermal maturity, oil-oil correlations and primary and secondary oil migration. Knowledge on trace element characteristics of crude oil is also important in oil refining strategies to prevent contamination of catalysts as well as equipment corrosion, and to minimize environmental pollution. In the case of vegetal oils and fats, the presence of certain elements, even in low concentrations ((mi)g g-1); can speed up oxidative processes and premature rancidity of oils, which may cause pathological effects in the digestive system, including cancer. Spectrometric techniques based on inductively coupled plasma (ICP OES and ICPMS) are extensively used for determination of trace elements in such type of samples due to their sensitivities and multielemental features. In the case of oils and fats, the samples have to be generally decomposed by wet-ashing procedures with mineral acids, prior to the elemental determinations. In this work, new strategies for sample preparation of crude oil, diesel, asphaltenes, edible oils, butter and margarine have been developed, which allow the use of the traditional procedure for sample introduction into the ICP by solution nebulization. In the case of diesel oil, the proposed strategy was the preparation of samples as emulsions with n-propanol. Factorial design studies showed that the important factors for the quantitative determination of refractory metals were the sample amount in the emulsion (up to 25% in weight) and the acidification of the emulsion. Crude oil samples, vegetable oils and fats have been prepared as n-propanol microemulsions. Alternatively, an ultrasound-assisted trace metal extraction procedure was developed. The crude oil emulsions with n-propanol were found to be a good environment to keep the analytes in solution. In the case of the ultrasound-assisted acid extraction for crude oil, a factorial design indicated that the important factors for the determination of trace elements have been the sample heating time, the nitric acid concentration and the ultrasound exposure time. For vegetable oils and fats, the optimization of the npropanol emulsion components provided good stability and homogeneity olive and soy oils (6 % of oil in weight) and for margarine and butter (5 % of oil in weight). For the ultrasound-assisted acid extraction, the optimized conditions for sample preparation also allowed the analysis of the extracts by ICP-MS, which results were compared with the ones obtained by ICP OES. For asphaltene samples, the proposed procedure was the ultrasound- assisted acid extraction in concentrated HNO3 using similar conditions employed for crude oil. The figures of merit for the proposed methods were achieved under optimized experimental and instrumental conditions and validations were performed by analysis of certified reference materials (when available), recovery tests, and by comparison of results obtained using traditional sample preparation procedures for this type of sample. Methods for the determination of Cr, Mo, V and Ti in fuel and diesel oils, for Cd, Co, Cr, Fe, Mn, Mg, Ni, Ti, V and Zn in crude oil and for Fe, Ni and V in asphaltenes have been developed. Cd, Co, Cr, Cu, Mn and Ni in edible oils and fats have been determined using the microemulsification in n-propanol, while Al, Ca, Cd, Cu, Fe, Mg, Mn, Ni, V and Zn have been determined after acid extraction in HNO3. The analyses were carried out by using the external calibration method with internal standardization by Sc (in the case of ICP OES). The ultrasound-assisted acid extraction method for t
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Marcos-Dominguez, Ana Maria. "Investigation of chemometrics methods for characterising drift phenomena in ICP-AES." Thesis, University of Plymouth, 2001. http://hdl.handle.net/10026.1/1679.
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The objective of this study was to fully characterise drift phenomena in inductively coupled plasma atomic emission spectroscopy (ICP-AES) in order to develop novel correction procedures to aid routine analysis. Long-term drift of the analytical signal continues to be a potential disadvantage when using ICP-AES and often necessitates regular recalibration. The long-term stability of three commercially available Instruments was studied using In each case a range of analyte and intrinsic plasma emission lines. Long-term fluctuations were observed which generated drift bias of up to 20% on the initial values. The drift pafterns were characterised and found to be qualitatively reproducible. In most cases, similar long-term fluctuations were observed independent of the analyte or nature of the emission line. In addition, high inter-element correlation was observed on the long-term fluctuations even when sequential acquisition was employed. In order to study the fundamental causes of drift, the effect of two key instrumental parameters, i.e. the RF power and the nebutiser gas flow rate were studied with respect to the stability of the signal. Different drift patterns were found depending on the working conditions. Classical statistical methods and a multi-way approach. PARAFAC. were then employed to describe the system. The use of intemal standards to correct for drift has also been investigated, but found to be of benefit only under certain defined conditions (i.e. robust conditions, high RF power and low nebuliserflow rate). At soft conditions, low RF power and medium to high nebuliser flow rate, the system Is very unstable and intemal standardisation is not fully effective as a correction method. For such conditions, a novel correction procedure has been developed, which employs the drift pattem of one intrinsic plasma line (i.e. an argon line) and a correction factor which is specific for each emission line. The drift values were reduced from around 20% before correction to better than ±2% following the described protocol. Finally, the effects of chemical matrices on the long-term stability of the emission signals have been evaluated. Three synthetic matrices were prepared simulating nitric, soil and water matrices. The stability of the instrument when working wrth these matrices at both robust and soft conditions was found to be poor, especially when the solution was matched with the soil matrix. The use of more robust conditions did not improve the long-temi stability of the emission signals. The outcome of this study proved to be a better understanding of drift phenomena and a novel method for drift correction.
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Kaňová, Veronika. "Studium různých metod přípravy vzorku mléka pro analýzu mléka technikou ICP-OES." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-295693.
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The theoretical part of the thesis deals with the chemical composition of cow’s milk, with the description of chosen methods of sample pretreatment and with the description of the used technique ICP-OES. The practical part is aimed at individual preparations of samples and at analysis of chosen chemical elements (Ca, Na, K and Mg). Milk is a really complicated polydisperse system, that’s the reason why the preparation of samples with milk is very important step before the measurement itself. In addition to accuracy choosing the sample adjustment method, other factors such as time, work intensity, or cost need to be considered when. In the thesis a comparison of four selected methods of sample preparation was made: direct analyse of milk, dilution with addition of Triton X-100, wet microwave ashing and destruction of matrix with TMAH (tetramethylammonium hydroxide). Selected elements were analysed with the help of ICP-OES. This diploma thesis builds on the bachelor thesis, which deals with the same problem. Final concentrations were compared with certified values of skimmed powdered milk. Data showed that the most accurate are methods of preparation of wet microwave ashing and destruction of matrix with TMAH. By using these methods, the effect of the dairy matrix that caused problems in the analysis, was largely eliminated. The diluted samples with and without Triton X-100 showed a bigger anomaly of measuring than the mineralization of wet ashing which came to the loss of analyte because of fat elements contained in milk.
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Villaseñor, Milán Ángela. "Development and optimization of methods for elemental quantitative analysis of catalysts and polymers through laser ablation-ICP techniques." Doctoral thesis, Universidad de Alicante, 2018. http://hdl.handle.net/10045/97855.
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En la presente Tesis Doctoral la técnica de ablación laser acoplada a ICP-OES/MS ha sido empleada para analizar muestras sólidas, como catalizadores usados en el refinado del petróleo y polímeros. Se han llevado a cabo dos tipos de análisis, un análisis global de las muestras que proporciona información general y un análisis localizado que permite obtener información acerca de la distribución espacial de los elementos de interés en las muestras. Las diferentes variables de la técnica ablación láser son estudiadas con el fin de seleccionar aquellas que conducen una señal alta y estable, así como a un menor grado de fraccionamiento. Este estudio se realiza para cada tipo de muestra, ya que los resultados dependen de la matriz estudiada. Además, en esta Tesis doctoral se desarrolla un método de calibración para llevar a cabo un análisis cuantitativo de las muestras sólidas, basado en la deposición de patrones líquidos sobre la muestra sólida. Este método es conocido como “dried droplet calibration approach” (DDCA), y permite cuantificar elementos presentes en muestras sólidas sin necesidad de usar materiales de referencia sólidos. Este nuevo método de calibración compensa el fraccionamiento elemental y los efectos de matriz, proporcionando resultados exactos y preciosos para muestras complejas tales como vidrios, catalizadores y polímeros.
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Wu, Meng. "ICI Reduction Methods for MC-CDMA Systems." Wright State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=wright1222376028.
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Cáceres, Ana B. "The development of methods for the determination of selenium using spectrofluorimetric and ICP-MS techniques." Thesis, Sheffield Hallam University, 2002. http://shura.shu.ac.uk/19425/.
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Methods for both the on-line and off-line fluorimetric determination of total selenium and selenium species using 2-(alpha-pyridyl)-thioquinaldinamide (PTQA) as a fluorimetric reagent have been developed. As PTQA is not available on the market, methods for its synthesis were critically reviewed, and in the light of the information obtained, modifications were made to the synthesis and purification conditions in order to improve yield from 16 % to 38.9 %. The synthesised PTQA was used for the optimisation of a batch fluorimetric method based on the reaction between the reagent and Se (IV) in acidic medium. The developed method was applied to the determination of total selenium in nutritional supplements after microwave digestion and photoreduction of Se (VI) to Se (IV). The analytical precision in the concentration range 0. 5 - 1000 mug ml[-1] was better than 5%. Excellent agreement (r[2] = 0.9960) between the results of the fluorimetric and ICP-MS methods was obtained when a reference material, TMDA 51.2 supplied by National Water Research Institute Environment Canada and three nutritional supplements were analysed. A novel automated fluorimetric method for the simultaneous determination of Se (VI) and Se (IV) is described in which a purpose built flow injection system was used for the on-line photoreduction of Se (VI) to Se (IV) before detection. Variables such as tube diameter, flow rates, type of acids (HNO[3], H[2]SO[4], CH[3]COOH, H[3]PO[4] and HCI) that affect the rate at which PTQA reacted with Se (IV) were investigated and optimised. The linear calibration range was found to depend on the type and concentration of acid. The most intense fluorescence signals were observed in HNO3 and at a PTQA concentration of 5x10[-4] M. A sample throughput of 8 samples/hr was achieved. Method validation was by comparing the results obtained for the determination of selenium in nutritional supplements with those from ICP-MS.Selenium speciation in the nutritional supplements was studied using a developed method in which the selenium species selenomethionine, Se (IV), and Se (VI) were extracted, separated by HPLC prior to on-line photoreduction of Se (VI), and post column hydride generation before ICP-MS detection. Separation of the three species was achieved with excellent resolution in less than 18 minutes. The limit of determination for the three species was 0.50 mug L[-1].
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Maibusch, Ralf. "Neue Methoden zur Feststoffanalytik unter Einsatz eines Induktiv Gekoppelten Plasma Massenspektrometers (ICP-MS)." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=967616824.
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Diaz-Bone, Roland Arturo. "Untersuchung metall(oid)organischer Verbindungen nach biologischer Abfallbehandlung mittels einer neu entwickelten GC-ICP-MS-Methode." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=98253566X.
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Maria, Aoun. "Development of Analytical methods for the evaluation of the impact of phosphate fertilizer industry on marine environment." Thesis, Pau, 2014. http://www.theses.fr/2014PAUU3033.
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Développement de méthodes analytiques pour l’évaluation de l'impact de l'industrie de fertilisants chimiques sur le milieu marinDevelopment of Analytical methods for the evaluation of the impact of phosphate fertilizer industry on marine environment
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Szarková, Lucia. "Podnikateľské riziká v poisťovníctve a ich kvantifikácia." Master's thesis, Vysoká škola ekonomická v Praze, 2014. http://www.nusl.cz/ntk/nusl-192614.
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Diploma thesis Business risks in insurance and their quantification describes the business risks to which insurance companies are exposed in their activities. Thesis is focused on market risk and quantification of market risk in insurance companies. It includes determination of the specifications for the activities of insurance companies, regulation and characteric of business risks in insurance. Large part of the thesis deals with the method of Value at Risk as a tool to measure market risk as well as individual methods to calculate it. In the conclusion, thesis describes the processes of quantification of market risk in Generali PPF Holding and in Česká poisťovňa, which gives a practical insight into the issues of market risk in insurance companies.
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Mackay, Neilson. "A comparison of three methods of ultrasound to computed tomography registration." Thesis, Kingston, Ont. : [s.n.], 2009. http://hdl.handle.net/1974/1666.
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Schmidt, Alexander. "ICPL - eine High-throughput-Methode für die quantitative Proteomanalytik." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=980266041.
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Winship, Peter D. "The development of ICP-MS methods for the study of biomedical problems particularly those involving nucleic acids." Thesis, Loughborough University, 2007. https://dspace.lboro.ac.uk/2134/17387.
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Inductively coupled plasma mass spectrometry (ICP-MS) is a well established and versatile technique for the elemental analysis of a wide spectrum of samples. For a majority of the elements that can be analysed by ICP-MS limits of detection in the order of sub ng 1 1 levels can be attained. However, a number of these elements have problems associated with them that lead to a restriction of the limits of detection that can be achieved. Phosphorus and Sulphur are two such elements that exhibit poorer limits of detection, the improvement of which would be highly desirable to the ICPMS analyst. Six methods for the measurement of 31p and 32S isotopes have been developed with the aim of avoiding the spectroscopic interferences at the native m/z ratios of 31 and 32 respectively. These approaches have utilised a hexapole collision cell, a 'cold/cool plasma' and an experimental ICP torch bonnet. Via the collision cell and 'cold/cool plasma' approaches the isotopes of interest were either converted to different species for successful measurement at an alternative m/z ratio or interfering species were removed allowing measurement at the native m/z. Limits of detection achieved by these approaches were comparable with those quoted in the literature and by ICP-MS instrument manufacturers. The approach using the torch bonnet was not successful in attenuating spectroscopic interferences; however, it did show potential for continuing as an area of research. The development of these six methods is discussed in Chapter 2. As an application of the successful methods developed for the measurement Of 31p and 328 isotopes, DNA (and its associated components) was selected for study as this biomolecule is comprised of approximately IO % phosphorus. DNA in solution was successfully quantified by these methods and DNA components, studied during polymerase chain reaction processes and in single nucleotide polymorphisms, were qualified. The application of these methods to the study of DNA and its components is discussed in Chapter 3. As part of a collaboration between the Loughborough University Atomic Spectroscopy Research Group and the Cancer Biomarkers and Prevention Group at the University of Leicester, ICP-MS was employed in the investigation of the interactions between two Pt based anti-cancer drugs (cisplatin and oxaliplatin) and their biological target DNA. For this collaboration, DNA was the interest common to both groups. The interaction of each of these drugs with known quantities of DNA was measured by ICP-MS and binding constant data was calculated for use as the basis of a clinical test for drug efficacy in cancer patients. The binding constant data showed that the interaction between drug and target is particularly inefficient. This area of research is discussed in Chapter 4. The potential for ICP-MS interface modification was also explored. Two modified designs are discussed that may prove to be advantageous for the transport of ions between the atmospheric pressure conditions of the ICP ion source and the vacuum conditions of the mass spectrometer. One of these designs was successfully manufactured and produced positive data. Research into this design is being furthered by the Thermo Electron Corporation, the discussion of which is in Chapter 5. A further collaboration was established with both the Biomaterials-related Infection Group of the School of Medical and Surgical Sciences and the Polymer Group of the School of Mechanical, Materials and Manufacturing Engineering at the University of Nottingham. Here ICP-MS was employed in the measurement of silver leaching from a silver nano-particle impregnated polymer material that could be used in the production of catheters. Silver leaching from a catheter is potentially desirable due to its anti-microbial properties. The study of this leaching revealed that significant quantities of silver were being transferred from the polymer into surrounding human serum media over the period of seven days and beyond. For the most part this work was routine ICP-MS measurement, and did not involve research or development, so does not take part in the main body of this thesis. This work is discussed in Appendix 5.
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Gilenstam, Kajsa. "Gender and physiology in ice hockey : a multidimensional study." Doctoral thesis, Umeå universitet, Idrottsmedicin, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-30354.
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Background That men are prioritised over women has been called the “gender regime in sport”, and has in part been explained by the gender difference in performance. However, gender differences in physical performance between women and men can be debated to depend on how comparisons are made and on the fact that there are many different confounders that may influence the results. Even if attempts are made to overcome this and the groups of women and men are stated to be matched, there are still often differences in training experience in years, or differences in training load. Women tend to have less experience in ice hockey in relation to age and differences in training conditions have also been reported. The aim of this thesis was to investigate how female and male ice hockey players position themselves in their sport and to visualise the interactions between society and biology that may affect performance. Theoretical approach and methods Harding’s three perspectives (Symbolic, Structural and Individual) were applied on information from team administration as well as on results from questionnaires, semi-structured interviews, and tests of puck velocity, anthropometrics, body composition, isokinetic muscle strength, ergospirometry and on-ice tests from female and male ice hockey players. Results Vast differences in structural conditions were found, for example in hockey history and in the financial situation within the teams and both women and men were aware of the gender differences in structural conditions. However these differences were not even considered when comparisons of the ice hockey performance of women and men were made. Nine out of ten female players increased puck velocity when a more flexible stick and a lighter puck were used thus indicating that poorly adjusted equipment may affect performance. Male ice hockey players were taller, heavier and stronger, had more lean body mass and a higher aerobic capacity compared to the women in absolute values as well as in relation to body weight. However, the differences diminished or disappeared when the values were expressed in relation to lean body mass. Men had higher expectations on their situation as athletes and the interviewed women described men’s ice hockey as superior to theirs and consequently male ice hockey players deserved better conditions. Conclusions The views of women and men may affect structural conditions in sport which in turn may affect possibilities in sport for the individual. Gender differences in conditions thus risk confirming the traditional views of femininity and masculinity. However, by moving outside the normal gender boundaries individuals may change the traditional views of femininity and masculinity.
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Pasteris, Daniel R. "A continuous method for measurement of pH and acidity in ice cores." abstract and full text PDF (UNR users only), 2009. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1464455.
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Ostatek, Jan. "Systém ICT rolí a jejich hodnocení." Master's thesis, Vysoká škola ekonomická v Praze, 2008. http://www.nusl.cz/ntk/nusl-12379.
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This diploma thesis addresses the ICT employee evaluation methods in conjunction with their ICT roles. The objective of this work is to produce the lead-in for ICT managers, Human Resources staff etc. for creation of employee evaluation systems or motivation programs in the workplaces with high rate of ICT professions. The work strives to combine psychological and informatics insight to offer corresponding evaluation instruments for each ICT role.
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Pietilä, H. (Heidi). "Development of analytical methods for ultra-trace determination of total mercury and methyl mercury in natural water and peat soil samples for environmental monitoring." Doctoral thesis, Oulun yliopisto, 2014. http://urn.fi/urn:isbn:9789526206202.
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Abstract Mercury is a global pollutant that accumulates easily in forest soils, even in remote areas. Mercury accumulated in soils can be subsequently released into surface waters causing an increased eco-toxicological and human health risk. The most toxic form of mercury to humans and wildlife is methyl mercury (MeHg), which can be formed in the environment via methylation processes. In freshwaters, MeHg is readily accumulated in fish, which are the main source of human exposure to MeHg. The determination of both total mercury and MeHg concentrations in environmental samples, such as natural waters and soils, is important in environmental risk assessment. This study involved the development of analytical methods for the determination of ultra-trace total mercury and MeHg concentrations in humic-rich natural water and peat soil samples. Each developed method was carefully optimized and validated by using real natural water and peat soil samples, certified reference materials and/or reference methods. The cold vapor inductively coupled plasma mass spectrometry (CV-ICP-MS) method developed during this study was found to be a reliable method for the determination of total ultra-trace mercury concentrations in natural freshwaters. Purge and trap gas chromatography, coupled to an ICP-MS, was used in mercury speciation analysis. Together with species-specific isotope dilution this technique proved to be a reliable method in MeHg determinations. Prior to instrumental determination, MeHg was successfully isolated from humic-rich water and peat soil samples using N2-assisted distillation. The analytical methods developed in this study were successfully applied to an investigation of the effects of forest harvesting practices on the mobilization of mercury in boreal forest catchmentsTiivistelmä Elohopeaa pääsee ilmakehään sekä luonnollisista lähteistä (mm. tulivuorenpurkaukset ja kiviaineksen rapautuminen), että ihmisen toiminnan kautta. Elohopean viipymäaika ilmakehässä on hyvin pitkä, minkä vuoksi se voi kulkeutua kauas päästölähteestä ennen päätymistään maaperään ja vesistöihin. Ympäristössä olevasta epäorgaanisesta elohopeasta voi muodostua erittäin myrkyllistä metyylielohopeaa, joka rikastuu helposti ravintoketjussa. Metyylielohopean muodostuminen on merkittävä osa elohopean biogeokemiallista kiertoa, minkä vuoksi metyylielohopean määrittäminen näytteen kokonaiselohopeapitoisuuden ohella antaa tärkeää tietoa elohopean käyttäytymisestä ympäristössä. Tutkimuksessa kehitettiin analyysimenetelmät, joilla määritettiin ultrapieniä kokonaiselohopea- ja metyylielohopeapitoisuuksia humuspitoisista luonnonvesistä ja turvemaanäytteistä. Tutkimuksessa käytetyt näytteet oli kerätty turvemaametsien valuma-alueilta Sotkamosta. Luonnonvesinäytteiden kokonaiselohopeapitoisuuksien määrityksessä käytettiin kylmähöyrymenetelmää (CV) yhdistettynä induktiiviplasma-massaspektrometriaan (ICP-MS). Vesi- ja turvenäytteiden metyylielohopeapitoisuuksien määrityksessä elohopeaspesiekset erotettiin kaasukromatografisesti (GC) ja määritettiin isotooppilaimennus-ICP-MS:lla. Ennen GC-ICP-MS -määritystä näytteet esikäsiteltiin typpiavusteisella tislausmenetelmällä ja esikonsentroitiin ’purge and trap’ -tekniikalla. CV-ICP-MS ja ’purge and trap’ GC-ICP-MS -menetelmät optimoitiin huolellisesti sekä laiteparametrien, että reagenssimäärien suhteen. Menetelmillä saatavien tulosten oikeellisuus varmistettiin vertailumateriaalien ja/tai vertailumenetelmien avulla. Kehitettyjä analyysimenetelmiä hyödynnettiin tutkimuksessa, jossa seurattiin metsähakkuiden mahdollisia vaikutuksia elohopean huuhtoutumiseen ja metyloitumiseen ojitetuilla turvemailla