Os hidrocarbonetos policíclicos aromáticos nitrados (nitro-HPAs) são potencialmente genotóxicos, por isso existe um grande interesse na determinação analítica desses compostos no material particulado no ar. Os nitro-PAHs são emitidos diretamente para a atmosfera pela combustão incompleta ou podem ser formados in situ a partir dos HPAs precursores. Neste trabalho, são apresentados os resultados obtidos no desenvolvimento de um método de análise de nitro-HPAs (1-nitronaftaleno, 2-nitronaftaleno, 1-nitropireno, 2-nitropireno, 2-nitrofluoranteno, 3-nitrofluoranteno, 1,3-dinitropireno, 1,6- dinitropireno, 2-nitrofluoreno, 6-nitrocriseno, 7-nitrobenzo(a)antraceno, 9- nitroantraceno e 9-nitrofenantreno) por GCxGC. A separação destes compostos por GCxGC pode simplificar a etapa de pré-tratamento do extrato orgânico oriundo do material particulado no ar. A GCxGC promove a separação em duas colunas com mecanismos de separação diferentes, conectadas em série, o que resulta em uma capacidade de separação maior. O sistema GCxGC empregado neste trabalho possui um injetor com programação de temperatura (PTV), um modulador criogênico de dois jatos de CO2 líquido (Dual Jet) e um detector por ionização em chama (FID). A separação foi feita empregando a fase estacionária apolar 5% fenil polisilfenilene siloxano na primeira coluna (30 m / 0,25 mm / 0,25 µm) e a semipolar 14% cianopropilfenil polisiloxano na segunda coluna (1 m / 0,10 mm / 0,10 µm). Diferentes condições cromatográficas foram testadas, como: programação de temperatura no PTV, de 40-90ºC até 350ºC, com taxa de aquecimento de 2,2 e 14,5ºC/s; programação de temperatura no forno, de 40-90ºC até 300ºC, com taxa de aquecimento de 2, 2,5 e 3ºC/min; períodos de modulação de 3, 4 e 5s. O volume injetado foi 2µL, no modo splitless; a vazão do gás de arraste (He) foi constante e igual a 1 mL/min e o detector FID foi operado em 120 Hz. As larguras de pico medidas em 10% da altura variaram de 167 a 350ms para 1- nitronaftaleno e 6-nitrocriseno, respectivamente, e a capacidade de pico para o conjunto de colunas de separação usado foi estimada em cerca de 9800. Parâmetros de validação, tais como os limites de detecção (200 a 500 ng/mL) e de quantificação (650 a 1600 ng/mL) para alguns nitro-HPAs foram determinados. Para a quantificação, foram testados os métodos por padronização interna e externa, sendo que, através dos resultados deste trabalho, pode-se mostrar que a determinação de nitro-HPAs por GCxGC com o modulador empregado é possível se for feita através do método de padronização interna. O sistema GCxGC empregado causou dificuldades operacionais, principalmente na conexão das colunas e na modulação. Perdas de massa de analito foram detectadas nas análises por GCxGC, muito provavelmente causadas por uma conexão parcial das colunas. Isso poderia ser evitado se a conexão fosse feita pela fusão das colunas a um conector de vidro adequado a essa finalidade. Picos modulados divididos foram observados com frequência, o que comprometeu a precisão e exatidão dos resultados. A divisão dos picos ocorreu de modo aleatório dificultando a identificação da causa mais provável para a sua ocorrência. Cromatogramas GCxGC de extratos orgânicos não fracionados de particulados no ar, oriundos de queima direta de palha de cana-de-açúcar, de região afetada pela queima de cana-de-açúcar e de área urbana da cidade de São Paulo, mostraram a potencialidade do método / Nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) are potentially genotoxic, so there is a great interest in the analytical determination of these compounds in airborne particulate matter. The nitro-PAHs are emitted directly into the atmosphere by incomplete combustion or may be formed in situ from PAHs. In this work, results obtained from the development of an analytical method for nitro-PAHs by GCxGC are presented. The nitro-PAHs studied were: 1- nitronaphthalene, 2-nitronaphthalene, 1-nitropyrene, 2-nitropyrene, 2- nitrofluoranthene, 3-nitrofluoranthene, 1,3-dinitropyrene, 1,6-dinitropyrene, 2- nitrofluorene, 6-nitrochrysene, 7-nitrobenzo(a)anthracene, 9-nitroanthracene and 9- nitrophenanthrene. The separation of these compounds by GCxGC should simplify the pretreatment step of the airborne particulate organic extract. In GCxGC two capillary columns of different mechanisms of separation are coupled by an interface called modulator, which increase significantly the chromatographic resolution. The GCxGC system used in this work is equipped with a PTV injector, a dual-stage double jets CO2 cryogenic modulator and a flame ionization detector (FID). The separation was carried out using a nonpolar stationary phase 5% methyl phenyl polysiloxane in the first column (30 m / 0.25 mm / 0.25 µm) and a semipolar 14% cyanopropyl phenyl dimethyl polysiloxane in the second column. Different chromatographic conditions were tested: the PTV was programmed from 40-90ºC to 350ºC at 2.2 and 14.5ºC/s; the oven was programmed from 40-90ºC to 350ºC at 2.0, 2.5 and 3.0ºC/min; the modulation periods tested were 3, 4 and 5s. The injected volume was 2µL in splitless mode, the carrier gas (He) flow rate of 1 mL/min was constant and the FID detector was operated at 120 Hz. Validation parameters, such as the limit of detection (200 - 500 ng/mL) and quantitation (650 - 1600 ng/mL) were determined. For quantification, the internal and external standardization methods were tested, and through the results of this study, it can be shown that the determination of nitro-PAHs by GCxGC with the modulator used is possible if made by internal standardization method. The GCxGC system presented operational difficulties, particularly in the column connection and in the modulation zone. A partial connection of the columns resulted in mass loss of the analytes. The connection of the columns could be more effective if it was made by fusing the columns to a glass connector suitable for this purpose. Divided modulated peaks were frequently observed, which compromised the precision and accuracy of the results. The division of the peaks occurred randomly hindering the identification of the most likely cause for its occurrence. GCxGC chromatograms corresponding to unfractionated organic extracts of airborne particulate material from the sugarcane straw burning, from an area impacted by sugar cane burning emissions and from an urban area of São Paulo City showed the capability of the method.

L'évaluation de l'inertie des matières plastiques au contact de denrées alimentaires est régie par le règlement européen N°10/2011. Au Liban, l'absence de législations relatives à l'usage des matières en plastiques a conduit à des emballages non contrôlés au niveau de la production et du stockage, ce qui peut induire un risque sanitaire pour le consommateur. L'objectif de ce travail a été d'apprécier les phénomènes de migration des contaminants du PET vers l'eau. Pour cela, l'analyse de certains migrants potentiels a été initiée tels que des COV et des SV afin de vérifier la conformité de leur teneur par rapport aux LMA dans les règlementations internationales. Le dosage des aldéhydes dans l'eau a été effectué par dérivation avec la 2,4-DNPH, suivie d'une étape de préconcentration sur une cartouche en C18, puis séparation et quantification par HPLC-UV. L'analyse des composés SV a été réalisée par SPME-GC-FID sur une fibre en PDMS/DVB. L'analyse des BTEX et du styrène a été réalisée par HS-Trap-GC-FID. Ces méthodes ont été validées conformément à la norme NF T 90-210 avec des LQ inférieures aux LMA. L'analyse des COV dans l'eau embouteillée et dans le PET a été réalisée par HSTrap- GC-MS. La présence de FA, d'AA, de DEP et des BTEX dans l'eau embouteillée en PET a été confirmée. Il a été mis en évidence que la température et l'exposition solaire influencent la migration des aldéhydes. Les concentrations d'AA trouvées après incubation à 40ºC ne sont pas négligeables et peuvent modifier les propriétés organoleptiques de l'eau. L'analyse du PET montre la présence des hydrocarbures, des aldéhydes, des alcools, et des cétones / The inertness’ value of plastics that are on contact with foodstuffs is governed by the European rule N°10/2011. In Lebanon, the lack of the Rules and Regulations of plastics’ usage led for a non-controlled packing in production as in storage, which will cause a sanitary risk to the consumer and to the population. The purpose of this research was to appreciate the migration’s phenomena of contaminants from the PET to the water. For this, there was an analysis of potential migrants such as VOC and SV to verify their tenor’s conformity relative to the MCL in international regulations. The aldehydes’ dosage in the water was performed by the derivation with the 2,4-DNPH, followed by a concentration on a C18 cartridge, then separation and quantification was done by HPLC-UV. The SV compounds’ analysis was realized by SPME-GC-FID method on a PDMS / DVB fiber. The BTEX and the styrene’s analysis was done by HS-trap-GC-FID method. These methods were validated in accordance with standard NF T 90-210 with a LQ less than the MCL. The volatile compounds in the bottled water and in the PET were analyzed by HS-trap-GC-MS method. The presence of FA, AA, DEP and BTEX in the bottled water with the PET was confirmed. It was highlighted that temperature and sun exposition influence the aldehydes’ migration. The acetaldehyde’s concentration after incubation at 40ºC wasn’t negligible and can modify the water’s organoleptic properties. The PET’s analyze reveals the presence of hydrocarbons, aldehydes, alcohols and ketones

<div>Determination of the chemical composition of liquid transportation fuels emerged as a novel and important field of study after the introduction of advanced analytical instruments, which are capable of very detailed chemical analyses of complex mixtures. Aviation fuels make up a crucial portion of liquid transportation fuels. There are several significant challenges in the field of aviation fuels, including the development of optimal analytical methods for the determination of the chemical compositions of the fuels, fuel properties measurements, and correlations between fuel properties and chemical composition. This dissertation explores possible correlations between fuel chemical composition and its properties and proposes novel approaches. First, a detailed description of a method for the determination of the detailed chemical composition of all middle distillate fuels (diesel and aviation fuels) is presented. Second, the density was correlated to fuel composition. Additionally, the approach of measuring the density, the hydrogen content, and the carbon content via a GC×GC-FID was introduced. Lastly, it was discovered that minute differences in chemical composition can influence fuel properties. This finding is described in the last chapter, where three HEFA samples were investigated. </div>

Atmospheric aldol self-reactions of octanal, heptanal and hexanal in a range of aqueous H2SO4 w/v% concentrations as a catalyst were studied in both bulk liquid-liquid experiments and gas-liquid experiments. Initially, a new practical methodology was developed and enhanced to monitor aldol reactions in aqueous acidic media. The evaluation of a quenching and extracting method were performed, confirming the suitability, reliability and reproducibility of the extraction method. In bulk studies, aldol products of the three aldehydes were separated and identified by preparative HPLC, GC-MS and NMR. The major aldol products observed at high acid concentrations were alpha,β-unsaturated aldehyde (dimer), trialkyl benzene (trimer) and tetraalkylcycloocta-tetraene (tetramer). The trimer of octanal was formed as trioxane in low sulfuric acid concentration and the possible mechanism accretion reaction pathways of high and low acid concentrations are proposed in this study. A systematic kinetic study of octanal, heptanal and hexanal in the bulk experiments at 65, 60 and 55 w/v% H2SO4 at 294 K were monitored using gas chromatographic equipped with a flame ionisation detector (GC-FID). The rate constants were generally estimated using second order kinetics and observed to increase as a function of sulfuric acid concentrations and also as the chain length of aliphatic aldehyde increased. The aldol self-reaction in the bulk experiment was too fast at room temperature to be easily measured using a quenching method therefore attempts were made to follow the reaction at low temperature (0 °C). The result at low temperature indicated that the rate constant of aldehyde was reduced but there was an issue of rapid rise in temperature as a result of mixing concentrated sulfuric acid with aqueous solution of the aldehyde. A gas bubbling system was developed which better simulates atmospheric reality, and which also resolves the issue of temperature rise on mixing. Two different methodologies were used: one in which the aldehyde was continually added, and one where a fixed amount was added from the gas phase and the reaction was then allowed to proceed, monitored at selected time intervals. The precision and accuracy of the fixed method was then further improved by the addition of an internal standard (IS). Using this, the concentrations of aliphatic aldehydes (C6-C8) were calibrated using an experimentally determined response factor and used to follow the loss of the reactant aldehydes. Similar methods were applied to the aldol dimers (C6-C8), which were purified and used to calibrate the chromatographic response. The rate constant for octanal, heptanal and hexanal at 76 wt% and 294 K were 0.0969 M-1 s-1, 0.1497 M-1 s-1 and 0.2622 M-1 s-1 respectively. There are some observations based upon the results presented in this thesis that may be of atmospheric significance: (i) phase separation between organic and aqueous layers in both the bulk experiment and in the bubbling system; (ii) the acid strength dependence and concentration-dependence of the various products; (iii) the faster rates than previously reported, and variation between bulk and bubbling; and (v) the time-dependent colour changes. Further work to explore these observations is proposed.

The extraction procedures for the determination of polycyclic aromatic hydrocarbons (PAH) concentrations in sediment samples had been developed by using GC-FID and GC-MS. The optimized methods were soxhlet extraction, ultrasonic bath extraction and solid phase micro extraction (SPME). In order to search out the main factors affecting extraction efficiencies of the methods, factorial design was used. The best extraction method was chosen and optimum values for main factors were selected for the development of the extraction method for PAH determination in sediment samples. The accuracy of the method was verified by analyzing NIST SRM 1597 (complex mixture of polycyclic aromatic hydrocarbons from coal tar). The selectivitiy and sensitivity obtained were quite adequate for the determination of PAHs in sediment sample. The best extraction and analysis methods were then applied to determine 16 PAHs in sea sediments from &Ouml / l&uuml / deniz Lagoon, Mugla, Turkey and 19 PAHs in Ikizcetepeler Dam Lake, Balikesir, Turkey sediments to illustrate the capability of the selected extraction and analysis method to detect PAHs and to determine the status of the contamination.

The hip-flask defence is a common claim in drunkdrinking cases. In Sweden and Norway two different models are used to determinethese cases. In Sweden one blood and two urine samples taken 60 minutes apartare used for analysis. In Norway two blood samples taken 30 minutes apart areused. Sweden focuses on the rise or fall of alcohol concentration in urine(UAC), and the ratio between UAC and blood alcohol concentrations (BAC). Norwayfocuses on the rise or fall of the alcohol metabolite ethylglucuronide (EtG) and the ratio between BAC and EtG. The aim of this study wasto test the models for multiple intakes and with different alcoholic beverages.Thirtyfive participants ingested two doses, first0.51 g/kg of beer and later either 0.25, 0.51 or 0.85 g/kg of beer, wine orvodka. Blood and urine samples were obtained before and after alcoholingestion. Alcohol was measured by GC-HS, and the alcohol metabolite byUPLC-MS/MS. The results showed that there are kineticdifferences between single and repeated intakes, that there are no significantdifferences in kinetics from different alcoholic beverages and thatthe Norwegian model appears to be the stronger one in hip-flask determination.

Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós Graduação em Química Tecnológica e Ambiental, Escola de Química e Alimentos, 2010. / Submitted by Cristiane Silva (cristiane_gomides@hotmail.com) on 2013-03-26T16:43:15Z No. of bitstreams: 1 015 Adriana Neves Dias.pdf: 1206374 bytes, checksum: 1cbb9efe79ebbed837d737c5d8605fd1 (MD5) / Approved for entry into archive by Bruna Vieira(bruninha_vieira@ibest.com.br) on 2013-07-15T17:03:59Z (GMT) No. of bitstreams: 1 015 Adriana Neves Dias.pdf: 1206374 bytes, checksum: 1cbb9efe79ebbed837d737c5d8605fd1 (MD5) / Made available in DSpace on 2013-07-15T17:03:59Z (GMT). No. of bitstreams: 1 015 Adriana Neves Dias.pdf: 1206374 bytes, checksum: 1cbb9efe79ebbed837d737c5d8605fd1 (MD5) Previous issue date: 2010 / O biodiesel produzido para ser comercializado no Brasil deve estar de acordo aos padrões de qualidade estabelecidos pela resolução de 4 de fevereiro de 2010 da Agência Nacional do Petróleo, Gás Natural e do Biocombustível (ANP, 04/2010). Neste trabalho, foi estudada a aplicação dos métodos ASTM D 6584 e EN 14105 para o biodiesel de mamona e biodiesel oriundo de rota etílica. Ambos os métodos empregam GC (Cromatografia Gasosa, do inglês Gas Chromatography) com FID (Detecção por Ionização em Chama, do inglês Flame Ionization Detection) e reação de sililação com N-metil N(trimetilsilil)trifluoracetamida (MSTFA). Os compostos foram identificados para quantificação pelos tempos de retenção, para os diglicerídeos e triglicerídeos foram utilizadas bandas de tempo de retenção. Os parâmetros de validação considerados foram: curva analítica, linearidade, sensibilidade, robustez, precisão e exatidão. Os métodos ASTM D 6584 e EN 14105 apresentaram sensibilidade semelhante para todos os compostos. Foram escolhidas as condições cromatográficas estabelecidas pelo método ASTM D 6584 por ser mais rápido que o EN14105 e ter sensibilidade semelhante. O método apresentou boa linearidade com todas as curvas analíticas com r maiores que 0,999. A reação de sililação com MSTFA foi otimizada para o biodiesel etílico de mamona em virtude da sua composição química. Um volume de 500 μL de MSTFA foi escolhido para realização dos ensaios de exatidão e precisão. Os valores de exatidão ficaram entre 67 e 145,9% com valores de precisão menores que 11%. Foi avaliada a ocorrência de efeito matriz para biodiesel etílico de mamona, sendo que esse efeito foi considerado baixo para glicerol, monooleína e dioleína e médio para trioleína. Mesmo havendo efeito de matriz o preparo das curvas analíticas em solvente conforme sugerido pelos métodos de referência foi mantido. O método foi robusto frente às variações da composição química da matriz. Na aplicação do método, esse se mostrou adequado para amostras de biodiesel etílico de mamona, de girassol e da mistura de sebo e soja. / The biodiesel produced to be marketed in Brazil should be according to the quality standards established by the Resolution of February 4, 2010 of the Agência Nacional do Petróleo, Gás Natural e do Biocombustível (ANP, 04/2010). In this work, the application of the methods ASTM D 6584 e EN 14105 for castor oil biodiesel and biodiesel from ethylic routes was studied. Both the methods use Gas Chromatography with Flame Ionization Detection and silylation reaction with N-Methyl N-(trimethylsilyl)trifluoroacetamide (MSTFA). The compounds were identified by the retention times, and for di- and triglycerides were used bands of retention time. The validation parameters were: analytical curve, linearity, sensibility, robustness, precision and accuracy. The methods ASTM D 6584 e EN 14105 showed similar sensitivity for all the compounds. The chromatographic conditions established by the method ASTM D 6584 were chosen because it is faster than the method EN14105. The method presented good linearity with r greater than 0,999 for all analytical curves. The silylation reaction was optimized for the ethylic castor biodiesel because of its different chemical composition. A volume of 500 μL of MSTFA was chosen for the realization of the precision and accuracy assays. The accuracy values were between 67.0 and 145.9% with precision values lower than 11%. The matrix effect occurrence for ethylic castor oil biodiesel was evaluated. The effect was considered low for glycerol, mono- and diolein and it was considered media for triolein. But, the analytical curves were prepared in solvent even though the matrix effect. The method was robust regarding variations of the matrix chemical composition. In the application of the method, this proved to be suitable to the samplesof ethylic biodiesel of castor oil, sunflower and tallow/soybean mixture.

This thesis deals with the production and characterization of cheese analogues, ie products in which some of the dairy components are mutually or completely replaced by a non-dairy component. Model samples of fresh cheese and analogues of fresh cheese (standard) with the addition of linseed and rapeseed oil were produced by a standard technological procedure in MENDELU Brno. The content of bound and free fatty acids, volatile (aroma) substances and sensory quality was monitored in the samples. The main focus was to evaluate the effect of added vegetable oil on the monitored parameters. The fats from the sample were extracted with a mixture of diethyl ether and petroleum ether. Fatty acids were converted to methyl esters by boron trifluoride-catalyzed acid esterification and subsequently identified by GC-FID. The analysis found a higher content of fatty acids in cheese analogues in comparison with the control sample, also the content of unsaturated fatty acids increased. The HS-SPME-GC-MS method was used for the identification and semi-quantification of volatile substances (aromatic substances). 56 volatile compounds were identified in the samples; The percentage of individual chemical groups differed significantly, the highest content was found in the control sample. Sensory evaluation was performed using a scale and a serial test. In all of monitored indicators (apparence, color, consistency, smell and taste) the control sample was evaluated as best. As for the analogues the taste and smell of used oils were detected, which was unpleasant for the evaluators. The obtained results show that the addition of vegetable oils increases the nutritional value of cheeses (higher content of unsaturated fatty acids), but reduces their sensory quality and overall consumer acceptability.

The diploma thesis is focused on the study of chemical reaction products in prebiotic atmospheres. The theoretical part deals with the main theories of composing the atmosphere of the early Earth, hypotheses of the origin of life and genetic code in the form of RNA, the atmosphere of the moon Titan and the basic characteristics of the gliding arc discharge, and the analytical techniques used in the diploma thesis. In the experimental part, study of products was carried out by experimental atmospheric simulations in a special stainless steel reactor in various mixtures of gases N2, CH4, CO2 and O2. The electrical discharge for atmospheric simulation was generated by an electrode configuration for the gliding arc discharge and glow discharge. Detection and identification of chemical reaction products was performed by Gas Chromatography with Mass Spectrometry (GC-MS) and Flame Ionization Detector (GC-FID), Testo 350 M/XL and Proton Transfer Reaction Mass Spectrometry (PTR-MS). A theoretical kinetic model was created to predict and confirm the detected products. During the experiments, the dependence of the product intensity on changes in the composition of the gaseous mixture and the applied value of the electric current was also observed.

The presented work was focused on the comparison between the production of selected metabolites by carotenogenic yeasts and microalgae cultivated under conditions of external stress. The main metabolites of interest were carotenoids, further lipophilic substances and lipids. Biotechnological overproduction of these metabolites could serve as a source of potentially beneficial substances not only for the pharmaceutical, cosmetic and food industries, but also for the production of third generation biofuels. Recently, there has been a growing interest in biofuels primarily from microalgae, which have a high potential in biofuel production and seem to be a promising source. The theoretical part deals with the description of individual genera of carotenogenic yeasts, microalgae, cyanobacteria, chemical composition of produced metabolites and brief biosynthesis. In addition, individual methods for analyzing the production of the metabolites of interest were described. The experimental part is focused on the comparison of production of carotenoids, coenzyme Q, ergosterols (phytosterols) and lipids by yeasts, microalgae and cyanobacteria. As a source of external stress, temperature, salt and light stress were chosen. The strains of Rhodotorula glutinis, Rhodotorula mucilaginosa, Sporidiobolus pararoseus and Cystofilobasidium macerans were studied from the yeast strains. Microalgae and cyanobacteria were Scenedesmus obliqus, Scenedesmus dimorphus, Chlorella sorokiniana, Chlorella saccharophila, Botryococcus brauni, Synechococcus nidulans and Arthrospira maxima. The yeast and algal strains were optimized for growth, carotenoid and lipid production. Applied salt stress showed a significant liquidation effect on algal and cyanobacterial strains. The thesis also monitored the biological stress, so-called co-cultivation of microalgae and yeasts. Further experiments will be the subject of future work.