Orientador: Juliana Azevedo Lima Pallone / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-22T00:01:01Z (GMT). No. of bitstreams: 1 Oliveira_AnaAliceAndrade_M.pdf: 1712746 bytes, checksum: f7bd6bb2cad0015ebc180af686268e60 (MD5) Previous issue date: 2013 / Resumo: A partir da Resolução Nº 344, de 13 de dezembro de 2002, publicada pela Agência Nacional de Vigilância Sanitária, a fortificação de farinhas de trigo e milho com ferro e ácido fólico tornou-se obrigatória. No entanto, para garantir a eficiência do programa de fortificação, é importante obter dados sobre o consumo de ferro a partir dos alimentos fortificados e assegurar a qualidade destes produtos. Neste trabalho foi validada e aplicada uma metodologia para determinação de ferro por espectrometria de absorção atômica com chama em massas e bolos elaborados com farinha de trigo fortificada. Também foram realizadas determinações de umidade, acidez álcool solúvel e índice de peróxido, a fim de verificar a qualidade destes produtos. O teor de carbono residual nas amostras, após mineralização, foi determinado por espectrometria de emissão atômica por plasma indutivamente acoplado (ICP-OES). Os resultados revelaram que a digestão foi eficiente e que o método para determinação de ferro apresenta precisão, exatidão, linearidade e limites de detecção e quantificação adequados para aplicação em massas e bolos. Os resultados da determinação de ferro mostraram que, entre as amostras de macarrão massa seca, macarrão instantâneo, massa de pizza, massa de pastel, bolo e massa de lasanha o teor de ferro variou de 2,5 a 7,1 mg 100 g-1 (em média 5,0 mg 100 g-1), de 2,4 a 5,5 mg 100 g-1 (em média 4,3 mg 100 g-1), de 2,0 a 5,5 mg 100 g-1 (em média 3,8 mg 100 g-1), de 1,0 a 4,9 mg 100 g-1 (em média 2,9 mg 100 g-1), de 1,1 a 3,1 mg 100 g-1 (em média 2,1 mg 100 g-1) e de 0,7 a 4,7 mg 100 g-1 (em média 2,9 mg 100 g-1), respectivamente. Para o macarrão massa seca, macarrão instantâneo, massa de pizza, massa de pastel, massa de lasanha e bolo o teor de umidade variou de 9,5% a 12,3%, de 3,3% a 7,1%, de 19,5% e 29,6%, de 25,7% a 31,3%, de 26,6% a 33,1% e de 16,3% a 26,5%, respectivamente. Nas amostras de macarrão massa seca, macarrão instantâneo, massa de pizza, massa de pastel, massa de lasanha e bolo a acidez variou de 1,4 a 3,2 mL de solução 1 mol L-1 de NaOH 100 g-1, de 0,3 e 1,0 mL de solução 1 mol L-1 de NaOH 100 g-1, de 2,9 e 4,6 mL de solução 1mol L-1 de NaOH 100 g-1, de 0,9 e 6,6 mL de solução 1mol L-1 de NaOH 100 g-1, de 1,7 e 3,7 mL de solução 1 mol L-1 de NaOH 100 g-1 e de 1,3 a 2,5 mL de solução 1mol L-1 de NaOH 100 g-1. Nas amostras de macarrão instantâneo o índice de peróxido variou, em média, de 5,9 mEq kg-1 de gordura a 8,4 mEq kg-1 de gordura. Os resultados revelam que as amostras apresentam boa qualidade físico-química, entretanto, notou-se grande variação no teor de ferro nas amostras analisadas / Abstract: Brazilian Health Surveillance Agency (ANVISA) established, by resolution RDC Nº344, mandatory fortification of wheat flour and corn flour with iron and folic acid. However, to ensure the efficiency of the fortification program, it is important to get information about iron consumption from fortified food and guarantee the quality of the products. The aim of this study was to validate and apply a methodology for iron determination by flame atomic absorption in pasta and cake produced with wheat flour fortified with iron. In addition, humidity, acidity and peroxide index were determined to check the quality of the products. In order to assess the efficiency of the mineralization, residual carbon was determined by inductively-coupled plasma optical emission spectrometry. The results revealed that the mineralization was efficient and the method demonstrated accuracy, precision, linearity and adequate detection limit and quantification limit. The results of iron determination showed that the iron content of dried pasta, instant noodle, pizza dough, samosa dough, orange cake and fresh lasagna sheets ranged from 2,5 to 7,1 mg 100 g-1 (on average 5,0 mg 100 g-1), from 2,4 to 5,5 mg 100 g-1 (on average 4,3 mg 100 g-1), from 2,0 mg 100 g-1 to 5,5 mg 100 g-1 (on average 3,8 mg 100 g-1), from 1,0 to 4,9 mg 100 g-1 (on average 2,9 mg 100 g-1), from 1,1 to 3,1 mg 100 g-1 (on average 2,1 mg 100 g-1) and from 0,7 to 4,7 mg 100 g-1 (on average 2,9 mg 100 g-1),respectively. The humidity of dried pasta, instant noodle, pizza dough, samosa dough, pizza dough, fresh lasagna sheets and orange cake ranged from 9,5% to 12,3%, from 3,3% to 7,1%, from 19,5% e 29,6%, from 25,7% to 31,3%, from 26,6% to 33,1% e from 16,3% to 26,5%, respectively. The acidity of dried pasta, instant noodle, pizza dough, samosa dough, fresh lasagna sheets and orange cake ranged from 1,4 to 3,2 mL of 1 mol L-1 NaOH solution 100 g-1, from 0,3 to 1,0 mL of 1 mol L-1 NaOH solution 100 g-1, from 2,9 to 4,6 mL 1mol L-1 NaOH solution 100 g-1, from 0,9 to 6,6 mL 1mol L-1 NaOH solution 100 g-1, from 1,7 to 3,7 mL de solução 1 mol L-1 de NaOH 100 g-1 and from 1,3 to 2,5 mL 1mol L-1 NaOH solution 100 g-1, respectively. The peroxide index of instant noodle ranged from 4,0 mEq kg-1 to 12,0 mEq kg-1. The results reveal that samples had good physicochemical quality, however there was a wide variation in the products / Mestrado / Ciência de Alimentos / Mestra em Ciência de Alimentos

This diploma thesis deals with the retrieval of the content of tin in environmental media, the circulation in them and possibilities of the determination of tin in the environment. Summarizes available information on the properties of tin and its compounds, the occurrence and circulation of tin in environmental and determination of tin in environmental media, attention is paid to the determination of total tin content using method of ET-AAS. The experimental part is focused on optimization methods of determination for the ET AAS and selection of a suitable extraction procedure for determination of total tin content in soils and sediments. The best procedure for the determination of tin in the ET-AAS was applied to samples of soil, sediment and water. As the optimum matrix modifier was chosen the solution of Pd (NO3)2 in 5% ascorbic acid, the optimum pyrolysis temperature was 1400 °C and atomization temperature 2400 ° C. Neither of extraction procedures examined were found to be an appropriate procedure for the determination of tin in environmental samples and further work is necessary to optimize the method of separation.

The diploma thesis is devoted to study potential risks for living organisms resulting from inhalation of nanoparticles of chosen heavy metals. The main aim of this work is the investigation of organs from experimental white mice after their guided inhalation of lead nanoparticles. The samples of liver and lungs from these animals are taken in time periods during the inhalation experiments and processed by specific methods for their evaluation. After pressurized microwave assisted decomposition of selected samples of mice organs in high purity concentrated nitric acid the content of lead is determined by atomic absorption spectrometry with electrothermal atomization. Furthermore, the changes are monitored using the microscopy of histological slides stained with hematoxylin-eosin. The results of both approaches are evaluated and compared within the frame of this work.

The diploma thesis focuses on identifying the presence of platinum in soil samples by absorption spectroscopy. The work is divided into two parts, the theoretical part is focused on the occurrence and behavior of platinum in the environment, the fundamental chemical and physical properties of platinum, its importance in catalytic converters in cars, on solid phase extraction method and the method for the determination of atomic absorption spectrometry. The second part is the practical part, focused on the determination of the platinum amount in the soil samples in the city of Brno.

The topic of this diploma thesis was the speciation analysis of the toxicological important forms of the arsenic in urban particulate matter samples. The detection technique used in this work was atomic absorption spectrometry with quartz atomizer. Acetic acid, ammonium acetate, hydroxylamine, potassium hydroxide and sodium carbonate are recommended leaching agents for extraction of metals from urban particulate matter samples. Results of the presenting work are following: Acidic extraction reagents can be not recommended for the speciation analysis of the arsenic, because these reagents lower sensitivity of the determination of As3+ and As5+ too and destroy the quartz atomizer. Alkaline extraction reagents don't lower sensitivity of the determination of As3+ and these reagents don't destroy the atomizer, but lower sensitivity of the determination of As5+ was obtained. Recommended reagents aren't useful for extraction of the metals from urban particulate matter samples for the speciation analysis.

Multielement analysis of flue gas residues from secondary lead smelting was tested using seven decomposition methods on four different flue gas residues and certified reference materials (CRM) CPB-2 (Pb concentrate, CCRMP). The studied samples contained both silicates and also high contents of phases with Pb, primarily Pb chlorides and sulphates. Solutions prepared by various decomposition methods were analysed using ICP OES (Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Se, Si, Sn, Sr, Ti, Tl, V, Zn). Greater yields were found for most of the elements by combined decomposition (with fusion) and decomposition by sintering. Nonetheless, both methods exhibited major losses of volatile elements (As, Bi, Sb, Tl). Thus, one of these methods must always be combined with a method of decomposition in a closed system. The work also demonstrates that, for investigation of untraditional waste geological materials (e.g. flue residues from high- temperature industrial processes), it will be necessary in the future to produce new certified reference materials with anomalous chemical and mineralogical compositions, which are not currently available on the market. Laboratory extraction tests were performed on two different types of flue residues - kinetic (30 days) with ratio L/S...

This thesis deals with optimization of conditions of photochemical generation of volatile species of nickel for atomic absorption spectrometry. The volatile species of nickel were generated in the flow arrangement, when sample was injected to a stream of a reaction medium. Either formic acid was used as the reaction medium or formic acid with the addition of formate anions. Two types of a generator were tested, a generator with a PTFE tube wrapped around a mercury UV lamp and a high efficiency generator with an inside channel. At the same time, two types of a gas-liquid separator were tested. Diffusion flame was used as an atomizer due to its high robustness. Quartz atomizer didn't provide higher sensitivity and measurements had worse repeatability. All the parameters affecting atomization in the diffusion flame were optimized (flow rates and composition of gases, observation height). In the next section, conditions of generation (irradiation time, HCOOH concentration, addition of formate anions) were optimized. Interferences of inorganic acids in photochemical generation were investigated as well. It was found out that the generator with the inside channel provided slightly higher sensitivity and thus generation efficiency than the generator with the PTFE tube wrapped around. Transmission of...

EN The thesis is focused on a speciation analysis of arsenic with use of the hydride generation - cryotrapping - gas chromatography - atomic absorption spectrometry. The aim of this project was the development of a method and instrumentation of the speciation analysis of arsenic based on combination of selective generation of substituted hydrides with a detection by atomic absorption spectrometry and with use of the cryotrapping of generated arsenic species and their separation by the gas chromatography. In the first part of this work the effects of individual parameters which influence the separation in the gas chromatograph were studied. Especially, time of injection from the cryotrap into GC, temperature program, carrier gas flow and carrier gas flow through a "deanswitch". Optimization of these parameters is an attempt to achieve a satisfactory resolution of the individual peaks of arsenic species separated by gas chromatography. Furthermore, an adequate sensitivity of this method is required to be achieved in comparison to other methods that use AAS detection such as a combination of hydride generation with cryotrapping. For this reason, the detection limits and the quantification of arsenic species were important to be determined as well. A sampling coil was replaced by a sampling tip...

This Master thesis is a part of a project: Hydride atomizers for atomic absorption and atomic fluorescence spectrometry - new horizons (GA ČR, P206/17-04329S, principal investigator: prof. RNDr. Jiří Dědina, CSc. DSc.) of which the general target is to make a leap towards the ideal hydride atomizer by optimization of atomization based on the knowledge of the distribution of free atoms and hydrogen radicals inside the atomizers. This thesis contributes to the project by optimizing the atomization parameters for atomic absorption spectrometry with hydride generation. The atomization parameters were optimized for three different types of atomizers - multiatomizer, diffusion flame and "flame-in-gas-shield" atomizer using three different analytes - bismuth, lead and tin. Optimal atomization parameters were found for each of the atomizer and each of the analyte - carrier gas flow and flow of other gases if needed for the analysis. Calibration curves and analytical figures of merit such as sensitivity, LOD and LOQ were estimated. Final comparison is based on the data obtained from calibration curves. MDF and FIGS atomizers are mostly used with AFS detection and they provide lower sensitivity and higher detection limits with AAS detection in comparison with MMQTA. Since the analytes are known to trap...

This master's thesis deals with the optimization of conditions for photochemical generation of volatile species of cobalt. Volatile species of cobalt were generated in a flow injection system using a high-efficiency flow through UV generator from formic acid based medium. For detection a high-resolution continuum source atomic absorption spectrometer was used. The volatile species were atomized using a diffusion flame atomizer because of its high robustness. First the optimizations of the parameters affecting the atomization in the diffusion flame and the parameters affecting the transport of the volatile species from the UV generator into the atomizer were carried out (flow rates and composition of the gases, type of a separator, observation height). After that, the optimization of the parameters of the photochemical generation itself was carried out. These were the composition of a reaction medium (concentration of formic acid and formate, type of formate salt) and irradiation time. The possibility of generation of the volatile species from acetic acid based medium was also investigated, but no signal was observed. At chosen optimal conditions of generation the influence of potential interferents was examined, mainly from inorganic acids (HNO3 and HCl) and some transition metals (Fe, Cu and Ni)....