Orientadores: Felix Guillermo Reyes Reyes, Maria Teresa de Alvarenga Freire / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-16T23:01:27Z (GMT). No. of bitstreams: 1 Dutra_CamilaBraga_D.pdf: 1974104 bytes, checksum: 7a0aae96f3654e27fb7d553ee756e522 (MD5) Previous issue date: 2010 / Doutorado / Doutor em Ciência de Alimentos

A janela de detecção de etilglicuronídeo (EtG) parece variar de acordo com a intensidade de consumo de etanol. Assim sendo, o objetivo do presente trabalho foi desenvolver e validar uma metodologia empregando extração em fase sólida e GC-MS para a determinação de EtG urinário, no sentido de verificar sua janela de detecção entre um grupo de bebedores sociais e usuários crônicos. Os limites de detecção e quantificação obtidos foram 0,1 e 0,2 mg/L respectivamente. O método proposto demonstrou ser linear no intervalo de 0,2 a 100,0 mg/L (r2>0,99), exato e preciso. A janela de detecção de EtG em amostras de urina de cinco voluntárias após ingestão única e controlada de 0,5 g/kg de etanol variou de 24 a 35 horas. Amostras de urina foram coletadas de 14 pacientes internados em clínica de recuperação. Os resultados mostraram que a maioria deles provavelmente consumiu etanol, prejudicando a interpretação dos resultados. Nos casos em que a concentração urinária de EtG foi decaindo no decorrer do tempo, a janela de detecção variou de 72 a 120 horas. O método mostrou ser útil para monitorar a abstinência durante o tratamento de pacientes dependentes de etanol ou o consumo após uma única exposição em baixa dose. / The detection range of the ethylglicuronide (EtG) seems to vary in accordance to the intensity of ethanol consumption. Thus, the objective of the present work was to develop and validate a method using extraction in solid phase and GCMS for the determination of urinary EtG, in order to verify its detection window in a group of social drinkers and chronic ethanol users. The limits of detection and quantification were 0,2 and 0.1 mg/L, respectively. The method showed to be linear in the interval of 0,2 to 100,0 mg/L (r2>0,99), and presented good accuracy and precision. The urinary EtG detection range in samples of five volunteers after controlled ingestion of 0,5 g/kg of ethanol varied between 24 to 35 hours. Urine samples were also collected from 14 patients from a recovery clinic. The results showed that the majority of them probably consumed ethanol, which compromised the interpretation of the results. In the cases where the urinary concentration of EtG decayed with time, the detection window varied from 72 to 120 hours. The method showed to be useful to monitor the ethanol abstinence during treatment of alcoholic patients or the consumption of only one ethanol low dose.

Os antidepressivos pertencem a uma importante classe de medicamentos investigados na toxicologia forense. Em casos de amostras provenientes de cadáveres, o intervalo entre o óbito e a obtenção da espécie biológica pode proporcionar a redistribuição postmortem destes fármacos. Com o objetivo de elucidar esse fenômeno, métodos analíticos foram desenvolvidos e aplicados utilizando sangue total (ST), humor vítreo (HV) e fígado. Para as amostras de ST e HV, o método de extração escolhido e validado foi a microextração em fase líquida (LPME) trifásica. Fibras ocas constituídas de polipropileno, com a extensão de 8 cm cada, foram tratadas com o solvente orgânico dodecano (fase orgânica), resultando em um membrana com permeabilidade seletiva. No lúmen destas fibras, adicionou-se ácido fórmico 0,1 mol/L (fase aceptora). Em frasco de fundo chato com 5 mL de capacidade, pipetou-se 3,5 mL de NaOH 0,1 mol/L (fase doadora) e 0,5 mL de ST ou HV. Ao término da extração, as amostras foram introduzidas no GC-MS, sem a necessidade de reações de derivatização. O estudo com ST contemplou os antidepressivos amitriptilina (AMI), nortriptilina (NTR), imipramina (IMI), desipramine (DES), clomipramina (CLO), desmetilclomipramina (DMC), fluoxetina (FLU) e norfluoxetina (NFL). Os limites de quantificação para estas substâncias ficaram inferiores aos níveis terapêuticos (20 ng/mL). As médias dos coeficientes de variação intradia e interdia foram, respectivamente, de 9,7 e 9,8%. As curvas de calibração apresentaram linearidade entre as concentrações de 20 até 1200 ng/mL. A validação do parâmetro integridade da diluição assegurou a mensuração de quantidades superiores ao limite apresentado na curva de calibração. O método foi aplicado em sete amostras reais postmortem e em apenas um caso foi observada uma diferença significativa (300%) entre os valores quantificados no ST periférico e central. Os antidepressivos tricíclicos AMI, NTR, IMI e DES foram avaliados no HV e o efeito matriz foi detectado para os dois últimos analitos. O método foi otimizado e validado utilizando solução salina adicionada de AMI e NTR. O limite de detecção igual a 5 ng/mL, foi obtido com a redução da voltagem da fonte de íons do espectrômetro de massa para 50 eV. Coeficientes de variação foram inferiores a 15%. Os procedimentos validados foram aplicados em seis amostras reais de HV. A relação encontrada entre os valores obtidos no ST periférico e HV foi de aproximadamente 0,1. A extração acelerada por solvente (ASE) e, posteriormente, a extração em fase sólida (SPE) foram as técnicas de separação dos analitos da matriz fígado. Ao término das citadas extrações, os antidepressivos foram analisados no GC-MS. Para esta matriz sólida, são necessários mais estudos, pois os valores encontrados nos ensaios analíticos estão em desacordo com as diretrizes utilizadas na validação dos métodos. / Antidepressants belong to an important class of drugs investigated in forensic toxicology. In cases of samples from corpses, the interval between death and obtaining the biological specimens can provide the postmortem redistribution of these drugs. Aiming to elucidate this phenomenon, analytical methods were developed and applied using whole blood (WB), vitreous humor (VH) and liver. For samples of WB and HV, the extraction method chosen and validated was the three-phase liquid phase microextraction (LPME). Hollow fibers consist of polypropylene, with a length of 8 cm each were treated with dodecane organic solvent (organic phase) resulting in a membrane with selective permeability. Into the lumen of these fibers was added formic acid 0.1 mol/ L (acceptor phase). In the vial containing 3.5 mL of NaOH 0.1 mol / L (donor phase) was spiked 0.5 ml of biological fluids (WB or VH). Subsequently, the samples were injected in GC-MS without derivatization reactions. The study of the ST included antidepressants amitriptyline (AMI), nortriptyline (NTR), imipramine (IMI), desipramine (DES), clomipramine (CLO), desmethylclomipramine (DMC), fluoxetine (FLU) and norfluoxetine (NFL). The quantification limits for these substances were below the therapeutic levels (20 ng / ml). The mean coefficients of variation and separate intradays were respectively 9.7 and 9.8%. The calibration curves showed linearity between concentrations of 20 to 1200 ng / mL. The validation of the integrity of the dilution parameter assured measurement higher than the limit shown in the calibration curve quantities. The method was applied to seven real postmortem samples and in one case a significant difference (300%) between the measured values in the peripheral and central ST was observed. The tricyclic antidepressants AMI, NTR, IMI and DES were evaluated in VH and the matrix effect was detected in the last two analytes. The method was optimized and validated using saline spiked AMI and NTR. The limit of detection (5 ng/ml) was obtained by reducing the voltage of the ion source of the mass spectrometer 50 eV. Coefficients of variation were below 15%. The procedures were validated in six real samples of HV. The relationship found between the values obtained in the peripheral ST and HV was approximately 0.1. Accelerated solvent extraction (ASE) and subsequently the solid phase extraction (SPE) were the techniques of separation of analytes liver matrix. At the end of the cited extractions, antidepressants were analyzed in GC-MS. To this solid tissue, further studies are needed, because the values found in the analytical tests were not in accordance with the guidelines used in the validation of the methods.

The growing need for fast sampling of explosives in high throughput areas has increased the demand for improved technology for the trace detection of illicit compounds. Detection of the volatiles associated with the presence of the illicit compounds offer a different approach for sensitive trace detection of these compounds without increasing the false positive alarm rate. This study evaluated the performance of non-contact sampling and detection systems using statistical analysis through the construction of Receiver Operating Characteristic (ROC) curves in real-world scenarios for the detection of volatiles in the headspace of smokeless powder, used as the model system for generalizing explosives detection. A novel sorbent coated disk coined planar solid phase microextraction (PSPME) was previously used for rapid, non-contact sampling of the headspace containers. The limits of detection for the PSPME coupled to IMS detection was determined to be 0.5-24 ng for vapor sampling of volatile chemical compounds associated with illicit compounds and demonstrated an extraction efficiency of three times greater than other commercially available substrates, retaining >50% of the analyte after 30 minutes sampling of an analyte spike in comparison to a non-detect for the unmodified filters. Both static and dynamic PSPME sampling was used coupled with two ion mobility spectrometer (IMS) detection systems in which 10-500 mg quantities of smokeless powders were detected within 5-10 minutes of static sampling and 1 minute of dynamic sampling time in 1-45 L closed systems, resulting in faster sampling and analysis times in comparison to conventional solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) analysis. Similar real-world scenarios were sampled in low and high clutter environments with zero false positive rates. Excellent PSPME-IMS detection of the volatile analytes were visualized from the ROC curves, resulting with areas under the curves (AUC) of 0.85-1.0 and 0.81-1.0 for portable and bench-top IMS systems, respectively. Construction of ROC curves were also developed for SPME-GC-MS resulting with AUC of 0.95-1.0, comparable with PSPME-IMS detection. The PSPME-IMS technique provides less false positive results for non-contact vapor sampling, cutting the cost and providing an effective sampling and detection needed in high-throughput scenarios, resulting in similar performance in comparison to well-established techniques with the added advantage of fast detection in the field.

La recherche de molécules organiques à la surface de Mars est l’un des enjeux majeurs pour caractériser son habitabilité passée et/ou présente. C’est l’un des objectifs de la mission spatiale Mars Science Laboratory (MSL) et en particulier de l’instrument Sample Analysis at Mars (SAM) à bord du robot Curiosity. Cette thèse s’inscrit dans l’aide au traitement et l’interprétation des données de SAM, en vue de détecter et d’effectuer l’inventaire des molécules organiques à la surface de Mars. Ces travaux portent en premier lieu sur les performances analytiques du chromatographe en phase gazeuse (CPG) de SAM et sur l’identification des molécules organiques dans les échantillons solides martiens analysés. A cette fin, j’ai étudié les performances de la chaine d’injection et de séparation du CPG de SAM dans les conditions opératoires de vol reproduites en laboratoire. J’ai également créé une base de données des temps de rétention de molécules présentes, et potentiellement présentes sur Mars, qui sert de référence pour le traitement des données de vol. Ces données ont permis d’identifier des molécules organiques dans les échantillons solides martiens et d’expliquer pourquoi certaines d’entre elles, supposées présentes, ne sont pas détectées. La deuxième partie de l’étude est focalisée sur l’impact des minéraux oxychlorés sur les molécules organiques, lors de la pyrolyse. Pour ce faire, j’ai développé une approche systématique d’étude de la pyrolyse de molécules organiques en présence de minéraux oxydants, ayant tous deux une forte probabilité de se trouver à la surface de Mars. J’ai ainsi pu étudier l’évolution et/ou destruction des molécules organiques, déterminer celles pouvant être à l’origine des composés chlorés détectés sur Mars, évaluer l’impact de la concentration en minéraux oxychlorés et celui du paramètre de température de pyrolyse. Les résultats indiquent que le nombre, la nature, et les abondances relatives des composés formés au cours de la pyrolyse, dépendent de la nature des phases minérales et organiques, de la concentration en minéraux oxychlorés et de la température de pyrolyse. / The search for organic molecules at the Mars’ surface is of primary interest to understand its past and/or present habitability. It is one among the main goals of the Mars Science Laboratory (MSL) space mission and especially of the Sample Analysis at Mars (SAM) experiment onboard the Curiosity rover. This thesis deals with the support to the SAM data treatment and interpretation, which aims to detect and inventory the organic molecules at the Mars’ surface. The first part of this work focuses on the analytical capabilities of the SAM gas chromatograph (GC) and the identification of the organics in the solid samples analysed on Mars with the flight model. To do so, I studied the analytical chain from injection to separation of the SAM GC in the flight operating conditions reproduced in the laboratory. I also created a library of retention times for molecules present or potentially present on Mars, and used as a reference library to treat the flight data. These data allowed to identify the organics in the martian solid samples, and to explain why a few molecules, expected to be present, are not detected. The second part of the thesis focuses on the impact of oxychlorine phases on the organics, during the pyrolysis process. With this aim, I developed a systematic approach to study the pyrolysis of organic molecules on the presence of oxidant minerals that have a high probability of presence at the Mars surface.The evolution and/or destruction of the organics was evaluated. We also looked for the organic and inorganic compounds that can be the precursors of the chlorohydrocarbons detected on Mars with SAM. Finally, we evaluated the influence of the oxychlorines concentration and of the pyrolysis temperature parameter. The results show that the number, the nature and the relative abundances of the compounds formed during the pyrolysis, depend on the nature of the organic and inorganic phases, of the concentration of the oxychlorines phases and of the pyrolysis temperature.

Synthetic musk compounds are artificial organic substances commonly used as fragrant constituents of personal care products as parfums, cosmetics, detergents, in-house cleaning and washing agents. Given their large area of applications and their ability to be persistent, they leaked into all parts of ecosystem, especially aquatic one. There have been a big focus on studiyng these compounds, their properties and fate in the different parts of ecosystems in the last years. The aim of master's thesis was carry out the determination of five representatives (habanolide, exaltolide, ambrettolide, musk MC4 and ethylene brassylate) of macrocyclic musk compounds in waste water samples from influent and effluent of three water treatment plants (WWTP Brno-Modřice, WWTP Lednice and WWTP Mikulov). One of the main tasks was to perform a method optimisation for the determination of selected musk compounds in waste water and evaluation and interpretation of the results. Solid phase microextraction (SPME) technique was used for the extraction of analytes, consequently gas chromatography-mass spectrometry was used for analysis of selected analytes. Following evaluation the removal efficiency of musk compounds in the waste water treatment plant was assessed.

This work is focused on the determination of polar pesticides in surface and waste waters. In this study Mecoprop-P, MCPA, Dichlorprop-P, 2,4-D and MCPBA in differently loaded surface waters and communal waters from sewage treatment plants were analyzed. These herbicides are included in the group identified as environmental quality standards. Some of herbicides (2,4-D and MCPA) were selected because their consumption in the Czech Republic exceeds 30 tons a year. Samples were collected prom three rivers near town of Jaroměř (Elbe, Úpa and Metuje Rivers), from one river near the town of Brno (Svratka River) and from inflow and outflow of two sewage treatment plants (WWTP Jaroměř, WWTP Brno – Modřice). Particular rivers were chosen for monitoring due to the probability of occurrence of herbicides, because they flow through agriculturally cultivated areas. Solid phase extraction (SPE) was used for the isolation of target compounds and their concentration. Gas chromatography with tandem mass spectrometry (GC/MS/MS) was used for the determination of target analytes in surface and waste waters. Selected herbicides were detected in all collected samples.

This dissertation is a collection of studies that investigates the issue of air pollution in the field of environmental chemistry. My thesis consists of research works done to measure the concentration of particulate matter (PM) and gas-phase species in ambient air. High concentrations of PM is a significant problem in Utah and in other regions of the world. Particles having an aerodynamic diameter of 2.5 micrometers and smaller play a crucial role in air pollution and pose serious health risks when inhaled. PM is composed of both organic and inorganic components. The organic fraction in PM ranges from 10-90% of the total particle mass. Several methods have been employed to measure the organic fraction of PM, but these techniques require extensive laboratory analysis, expensive bench top equipment, and do a poor job of capturing diurnal variations of the concentrations of ambient organic compounds. The Hansen Lab has developed a new instrument called the Organic Aerosol Monitor (OAM) which is based on gas chromatography followed by mass spectrometry detection platform for measuring the carbonaceous component of PM2.5 on an hourly averaged basis. Organic marker data collected in 2016 using the OAM was used in a Positive Matrix Factorization (PMF) analysis to identify the sources of PM in West Valley City, Utah. Additionally, data was collected in Richfield and Vernal, UT in 2017 - 2018 to quantitatively monitor the composition of organic markers of PM2.5. Some previously unidentified organic compounds in PM were successfully identified during this study, including terpenes, polycyclic aromatic hydrocarbons (PAHs), diethyl phthalate, some herbicides, and pesticides. Gas-phase species play a significant role in driving the formation of air pollutants in Earth's atmosphere. Traditional gas detection methods do not provide high temporally and spatially resolved data; therefore, it becomes important to detect and measure gas-phase species both qualitatively and quantitatively to better understand the sources of air pollution. An incoherent broadband cavity enhanced absorption spectrometer (IBBCEAS) combines a broadband incoherent light source, a stable optical cavity formed by two highly reflective mirrors and a charged-coupled device (CCD) detector to quantitatively measure the gas-phase compounds present in the atmosphere. The concentrations of formaldehyde (HCHO) were measured using IBBCEAS to investigate the sources of this hydrocarbon in Bountiful, Utah during 2019. Another important species is OH radical. It is one of the most predominant oxidizing species present in the atmosphere. It is found in low concentrations, 0.1 ppt. Detecting concentrations this low is challenging. A new IBBCEAS instrument has been designed and elements of this instrument were tested by measuring the OH overtones in a variety of short chained alcohols. A set of experiments were conducted to measure the absorption cross-sections for the 5th and 6th OH vibrational overtones in a series of short chained alcohols by IBBCEAS. Because OH radical's lowest energy electronic state occurs in the same wavelength region (i.e., 308 nm) that SO2 absorbs (300-310 nm), a study was conducted in which the concentrations of SO2 were measured using an IBBCEAS and compared with a commercially available SO2 monitor.

Fire debris analysis currently relies on visual pattern recognition of the total ion chromatograms, extracted ion profiles, and target compound chromatograms to identify the presence of an ignitable liquid. This procedure is described in the ASTM International E1618-10 standard method. For large data sets, this methodology can be time consuming and is a subjective method, the accuracy of which is dependent upon the skill and experience of the analyst. This research aimed to develop an automated classification method for large data sets and investigated the use of the total ion spectrum (TIS). The TIS is calculated by taking an average mass spectrum across the entire chromatographic range and has been shown to contain sufficient information content for the identification of ignitable liquids. The TIS of ignitable liquids and substrates were compiled into model data sets. Substrates are defined as common building materials and household furnishings that are typically found at the scene of a fire and are, therefore, present in fire debris samples. Fire debris samples were also used which were obtained from laboratory-scale and large-scale burns. An automated classification method was developed using computational software that was written in-house. Within this method, a multi-step classification scheme was used to detect ignitable liquid residues in fire debris samples and assign these to the classes defined in ASTM E1618-10. Classifications were made using linear discriminant analysis, quadratic discriminant analysis (QDA), and soft independent modeling of class analogy (SIMCA). The model data sets iv were tested by cross-validation and used to classify fire debris samples. Correct classification rates were calculated for each data set. Classifier performance metrics were also calculated for the first step of the classification scheme which included false positive rates, true positive rates, and the precision of the method. The first step, which determines a sample to be positive or negative for ignitable liquid residue, is arguably the most important in the forensic application. Overall, the highest correct classification rates were achieved using QDA for the first step of the scheme and SIMCA for the remaining steps. In the first step of the classification scheme, correct classification rates of 95.3% and 89.2% were obtained using QDA to classify the crossvalidation test set and fire debris samples, respectively. For this step, the cross-validation test set resulted in a true positive rate of 96.2%, a false positive rate of 9.3%, and a precision of 98.2%. The fire debris data set had a true positive rate of 82.9%, a false positive rate of 1.3%, and a precision of 99.0%. Correct classifications rates of 100% were achieved for both data sets in the majority of the remaining steps which used SIMCA for classification. The lowest correct classification rate, 69.2%, was obtained for the fire debris samples in one of the final steps in the classification scheme. In this research, the first statistically valid error rates for fire debris analysis have been developed through cross-validation of large data sets. The fire debris analyst can use the automated method as a tool for detecting and classifying ignitable liquid residues in fire debris samples. The error rates reduce the subjectivity associated with the current methods and provide a level of confidence in sample classification that does not currently exist in forensic fire debris analysis.

Red Lustrous Wheelmade Ware (RLWm ware) transport and storage vessels have been excavated from Late Bronze Age (LBA) sites across the eastern Mediterranean. These distinctive vessels were traded for the valuable commodity they contained so far unidentified. Seventy-three sherds (61 RLWm ware, 12 in local fabrics) and two visible residues were analysed for organic residues using standard lipid extraction techniques. Seven residues from a previous study were re-examined. Gas chromatography-mass spectrometry identified four materials ¿ beeswax, bitumen, fat/oil and resin. Beeswax, found only in vessels from Hittite sites in Turkey, was probably used as a post-firing treatment. Fat/oil, present in some sherds from every site, represents the contents of the vessels and showed many of the characteristics of degraded plant oil. Two examples contained a plant sterol and three yielded ricinoleic acid, a biomarker for castor oil. Gas-chromatography compound-specific isotope ratio mass spectrometry of selected residues excluded dairy products, ruminant animal fats and fish oils as source materials for the fats/oils, while comparison with a small database of modern oils created during this study does not exclude plant oils. Selected samples analysed by high performance liquid chromatography-tandem mass spectrometry did not reveal wine residues. Data on the elemental composition of the fabric collected during another study was re-analysed and compared with data from a further published study, confirming the remarkable consistency of RLWm ware fabric. Volume calculations were also attempted to give an estimate of the capacity of the main vessel forms. / Arts and Humanities Research Council / Extensive folders of data and appendices which accompany this thesis are not presently available online.