Universiẗat, Diss.--Münster, 1999.

La présence d’hydrocarbures dans l’environnement que ce soit suite à un déversement accidentel de pétrole en mer ou suite à des apports chroniques, est une préoccupation majeure en raison de leur écotoxicité et de leur potentiel à être bioaccumulés, et ainsi, pénétrer la chaîne alimentaire. Par conséquent, ces molécules sont sous haute surveillance et il est nécessaire de disposer de méthodes analytiques permettant de les identifier et de les quantifier, et ceci, pour des concentrations allant du mg/L au ng/L. Cependant et dans la plupart des cas, les analyses en laboratoire des hydrocarbures, notamment aromatiques, se limitent à la quantification des 16 hydrocarbures aromatiques polycycliques (HAP) identifiés par l’Agence américaine de Protection Environnementale (US-EPA) comme étant dangereux pour l’environnement du fait de leur caractère cancérigène. Or, les hydrocarbures aromatiques polycycliques soufrés (HAPS) ainsi que leurs homologues substitués sont, sur le plan chimique, structurellement proches des HAP, et peuvent donc présenter des risques environnementaux similaires, à savoir être cancérigènes ou mutagènes. Le travail de recherche réalisé s’inscrit dans ce contexte avec pour objectif des développements méthodologiques permettant l’extraction et l’analyse d’une gamme plus large de HAP, des HAPS et leurs dérivés alkylés directement dans les produits pétroliers ou dissous en phase aqueuse. Des protocoles d’extraction par "stir bar sorptive extraction" (SBSE) et par microextraction sur phase solide (SPME), et des méthodes d’analyse par chromatographie en phase gazeuse couplée à la spectrométrie de masse simple (GC-MS) et en tandem (GC-MS-MS) ont été développés. Les résultats obtenus plaident en faveur de ces méthodologies aussi bien en termes de linéarité de la réponse qu’en termes de sensibilité, méthodologies qui ont été appliquées avec succès pour la détermination des analytes d’intérêt dans des fractions solubles préparées au laboratoire (WAF et WSF). Pour la CG-MS-MS, si elle se révèle particulièrement adaptée car elle apporte un degré de certitude élevé, elle n’en reste pas moins une technique délicate à mettre en oeuvre, notamment dans le cas des composés alkylés pour lesquels des solutions étalons ne sont pas disponibles. Pour pallier cette difficulté, un produit de référence contenant l’ensemble des analytes d’intérêt a été caractérisé. Pour les composés alkylés non disponibles commercialement, des appro-ximations ont été effectuées par MS simple en se basant sur une analyse comparée des coefficients de réponse en mode MRM et SIM. La méthodologie ainsi mise au point a permis de caractériser le fioul de l’Erika avec une faible variabilité des résultats. Ce produit peut servir de référence pour l’analyse quantitative de l’ensemble des familles de composés identifiés dans cette étude. / The presence of hydrocarbons in the environment either as a result of oil spills at sea or due to chronic discharge is a major concern because of their ecotoxicity and their potential to bioaccumulate and thus enter the food chain. Therefore, these molecules are closely monitored and reliable analytical methods are required to identify and quantify them, for concentrations ranging from mg/L to ng/L. However, in most cases, laboratory analyses of hydrocarbons, especially aromatic hydrocarbons, are limited to the quantification of 16 polycyclic aromatic hydrocarbons (PAHs) identified by the U.S. Environmental Protection Agency (U.S. EPA) as hazardous to the environment due to their carcinogenic nature. However, polycyclic aromatic sulphur heterocycles (PASHs) and their substituted homologs are, in chemical terms, structurally similar to PAHs, and therefore can pose similar environmental risks, i.e. they can be carcinogenic or mutagenic. In this context, the research work carried out aims to develop methodologies for the extraction and analysis of a wider range of PAHs, PASHs and their alkyl derivatives directly in oil or dissolved in the aqueous phase. Extraction protocols by stir bar sorptive extraction (SBSE) and solid phase microextraction (SPME), and methods of analysis by gas chromatography coupled with mass spectrometry (GC-MS) and with tandem mass spectrometry (GC-MS-MS) have been developed. The results argue in favor of these methodologies both in terms of linearity of the response and in terms of sensitivity. These methodologies that have been successfully applied for the determination of analytes of interest in the water accommodated fraction and water soluble fraction prepared in the laboratory (WAF and WSF). For GC-MS-MS, while it is particularly suitable because it provides an additional level of selectivity, it is a difficult technique to implement, in particular in the case of molecules for which no calibration solutions are available. To overcome this difficulty, a reference oil containing all the target molecules was characterized. For alkylated compounds that are not commercially available, approximations were made by simple MS, based on comparative analysis of response coefficients in MRM (Multiple Reaction Monitoring) and SIM (Single Ion Monitoring) modes. The finalized method was used to characterize the Erika fuel oil, with low variability in the results. This product can be used as a reference for the quantitative analysis of all the families of molecules identified in this study.

Ziel dieser Arbeit war es, technologiebedingte Veränderungen im Profil flüchtiger Inhaltsstoffe während der Fruchtsaftverarbeitung aufzuzeigen. Gleichzeitig sollte eine Bewertung von artfremden ‚carry over’-Aromastoffen erfolgen und deren Einfluss auf das Aromaprofil eines Fruchtsaftes beurteilt werden. Hierzu wurden aus unterschiedlichen Phasen der Fruchtsaftherstellung authentische Proben (Direktsäfte, Recovery-Aromen, Saftkonzentrate) von der Schutzgemeinschaft der Fruchtsaftindustrie (SGF) zur Verfügung gestellt. Ergänzt wurde diese Palette durch industrielle Halb- und Fertigwaren, um Abweichungen vom geforderten authentischen Profil zu definieren. Es kamen dabei für die Fruchtsaftverarbeitung wesentliche Fruchtarten (Apfel, Orange, Ananas, Pfirsich und Passionsfrucht) zur Anwendung. Die Bestimmung der Aromaprofile erfolgte anhand validierter qualitativer und quantitativer Aromastoffanalytik. Nach Abtrennung und Anreicherung der Aromastoffe mittels Simultaner Destillation-Extraktion (SDE) wurden die Extrakte per Kapillargaschromatographie-Massenspektrometrie (HRGC-MS) analysiert. Durch den Einsatz sensorischer Untersuchungen wurden Schwellenwerte von ausgewählten ‚carry over’-Aromastoffen und ‚off-flavour’-Komponenten in fünf verschiedenen Matrices ermittelt. Zusammenfassend lässt sich an Einzelergebnissen festhalten: Das bei Ananasfrüchten erhaltene Aromaprofil entsprach weitgehend Literaturangaben. Während bei den geprüften Recovery-Aromen partiell gute Übereinstimmung mit dem Aromaprofil der Frucht gefunden wurde, war bei den Handelssäften aus Konzentrat meist nur die jeweils bei den entsprechenden Saftkonzentraten ermittelte, praktisch nur von Furaneol determinierte Aromastoffzusammensetzung zu finden. Die geprüften Direktsäfte – sieht man von ihren vergleichsweise hohen Acetoinanteilen ab - zeigten fruchtähnliche Aromaprofile. 2-Ethylhexansäure (2-EHA) wurde als technologiebedingte Kontaminante in Fruchtsäften und Babynahrung festgestellt. In 80% bzw. 73% der geprüften Babynahrung- und Fruchtsaftproben – darunter auch Bio-Produkte - wurde die Substanz nachgewiesen. Die im Tierversuch als teratogen eingestufte Verbindung migriert aus den Deckel-Dichtungen der Glasverpackungen in das Lebensmittel. Orangensaft-Fertigprodukte wiesen im Vergleich zu authentischen ‚single strength’-Proben einen niedrigeren Gehalt an Aromastoffen auf. Empfindliche Aromastoffe wie Ethyl-2-methylbutanoat und Z-3-Hexenal sind in den analysierten Handelsproben nicht mehr detektiert worden. Die Verbindungen Ethylbutanoat, Hexanal und Z-3-Hexenal wurden nur im Essenzöl von Orangen nachgewiesen, nicht aber in Schalenölproben. Eine eindeutige Unterscheidung von (wertvollem) Orangen-Essenzöl und (geringwertigerem) Orangen-Schalenöl ist derzeit ausschließlich anhand von HRGC-MS ermittelter Aromaprofile nicht möglich. Um 13C-markierte Standards zur Stabilisotopenverdünnungsanalyse (SIVA) zu erhalten, wurden entsprechende Synthesen für die wichtigen Komponenten des Orangenaromas, Limonen und a–Terpineol, durchgeführt. Mittels SIVA ist es möglich, diese Verbindungen in Orangensäften, aber auch in Kosmetika exakt zu quantifizieren. Als Hauptkomponenten des Aromaprofils von Apfelsäften und Recovery-Aromen sind die Verbindungen 1-Butanol, 1-Hexanol, E-2-Hexenal, E-2-Hexenol und Butylacetat bestätigt worden. Das produzierte Saftkonzentrat enthält neben Erhitzungsprodukten wie Furfural keine charakteristischen Apfelaromastoffe mehr. Das ubiquitäre Auftreten in allen industriell frisch gepressten Apfelsäften von 3-Methyl-1-butanol und dessen Acetat, beides bekannte Indikatoren für Gärprozesse, scheint technologisch schwer vermeidbar zu sein. Die große Spanne von 0,01 mg/l bis 2,1 mg/l 3-Methyl-1-butanol in Apfelsaft macht aber deutlich, dass sich der Gehalt an fermentativ gebildeten Komponenten während der Fruchtsaftverarbeitung durchaus gering halten kann. Eine legislative Regulierung zum Vorkommen dieser Stoffe in Apfelsaft ist erforderlich. Bei der destillativen Recovery-Aroma-Gewinnung aus Apfelsäften zeigte sich die Tendenz einer leichten Abreicherung der d2HV-SMOW–Werte von Saft zu korrespondierendem Destillat. Anhand von Korrelationen der ermittelten 13C/12C- und 2H/1H-Daten von 1-Hexanol, E-2-Hexenal und E-2-Hexenol wird deutlich, dass eine Authentizitätsbewertung aber von diesem marginalen Effekt nicht berührt wird. Die Spuren an Fremdaromen zeigen, dass es unter der technologisch üblichen Produktions- und Reinigungspraxis zu Kontaminationen von artfremden Aromastoffen im Verlauf der Fruchtsaftherstellung kommen kann. Die Kombination aus ermittelten Schwellenwerten von ‚carry-over’-Aromastoffen und deren tatsächliches Auftreten in Fruchtsäften zeigte, dass keine sensorische Beeinträchtigung der Produkte vorliegt. Ein höheres Potential, Produkte negativ zu beeinflussen, bergen die in Orangensäften in relevanten Gehalten nachgewiesenen ‚off-flavour’-Komponenten a–Terpineol und Carvon. / The aim of this study was to elucidate technologically caused changes in the profile of volatile components during fruit juice processing. In addition, the occurrence of ’carry-over’ aroma compounds foreign to the species and their influence on the aroma profile should be evaluated. For this, authentic samples from different stages of the fruit juice processing, i.e. ’single strength’-juices, recovery aromas, and fruit juice concentrates, were provided by the Schutzgemeinschaft der Fruchtsaftindustrie (SGF). Included were also industrial semi-finished products and fruit juices purchased in supermarkets, to define variations from the authentic profile. The most important species used for fruit juice processing (apple, orange, pineapple, peach, and passion fruit) were considered. The determination of aroma profiles was carried out by a validated qualitative and quantitative aroma analysis. Aroma compounds were separated and enriched by simultaneous distillation-extraction (SDE) and subsequently analysed by high resolution gas chromatography-mass spectrometry (HRGC-MS). Using sensory tests the thresholds of selected ’carry-over’-compounds and off-flavour-components in five different matrices were determined. Summarizing, the following informations were acquired: The obtained aroma profile of pineapple fruits corresponded to a large extent with that described in the literature. Whereas the recovery aromas accorded, in part, with the profile of the fresh fruit, the pineapple juices made from concentrate showed an aroma profile that was similar to the aroma composition of juice concentrates. These were essentially dominated by furaneol. The commercial ’single strength’-juices under study exhibited, apart from high amounts of acetoin, fruit-like aroma profiles. 2-Ethylhexanoic acid (2-EHA) was found as technological contaminant in fruit juices and baby foods. In 80% of the baby food and 73% of the fruit juice samples under study – among them products labelled ’organic’ – this substance was identified. Being known as teratogenic and potent carcinogeric compound for rodents, 2-EHA migrates from the plastic askets inside the metal lids into the food. Commercial orange juices contained lower amounts of aroma compounds compared to authentic ’single strength’-juices. Sensitive volatile components like ethyl 2-methylbutanoate and Z-3-hexenal were not detected in the commercial orange juices under study. The substances ethyl butanoate, hexanal and Z-3-hexenal were determined only in orange essence oil but not in any orange peel oil. An unambiguous differentiation between the high priced orange essence oil and the less valuable orange peel oil is not possible on the basis of HRGC-MS data to date. In order to obtain 13C-labeled standards for the stable isotope dilution assay, syntheses for important orange flavour compounds, i.e. limonene and a–terpineol were carried out. By means of these standards it was possible to quantify these substances in orange juices and cosmetics (limonene is one of the aroma compounds classified as allergenic and has to be declared on cosmetics containing a defined amount). The components 1-butanol, 1-hexanol, E-2-hexenal, E-2-hexenol, and butyl acetate were verified as main constituents of the aroma profile of apple juices and recovery aromas. Besides heating products such as furfural, the profile of the juice concentrates contained no characteristic apple aroma compounds. The ubiquitous occurrence of 3-methyl 1-butanol and its acetate, both known indicators for fermentation processes, seems to be technologically hard to avoid in industrial ’single strength’-juices. The wide range from 0.01 to 2.1 mg/l shows that the yield of 3-methyl 1-butanol can be minimized during fruit juice processing. Legislative regulations to determine limits of the presence of 3-methyl 1-butanol and its acetate in apple juice are necessary. Using distillative recovery of apple juice aroma the slight trend of a depletion of d2HV-SMOW values was observed from apple juice to the corresponding recovery aroma. The correlation of 13C/12C- and 2H/1H-values of 1-hexanol, E-2-hexenal, and E-2-hexenol showed that the authenticity assessment by stable isotope ratio-mass spectrometry is not affected by this negligible effect. The detected traces of ’carry-over’ components indicate that contaminations of aroma compounds can occur under normal fruit juice production conditions. However, the combination of determined thresholds and the real amounts of the substances in fruit juices showed that the commercial products are not influenced in their sensory quality. ’Off-flavour’ components of orange juices, i.e. a–terpineol and carvon, possess with their relevant amounts an increased potential to affect the taste and odour of commercial products.

Submitted by Gizele Lima (gizele.lima@inpa.gov.br) on 2016-08-31T13:21:43Z No. of bitstreams: 2 Tese de Doutorado_Angela Beth Jardine.pdf: 6114980 bytes, checksum: 07a301793e0522e5fb0084e12ee425fe (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-31T13:21:43Z (GMT). No. of bitstreams: 2 Tese de Doutorado_Angela Beth Jardine.pdf: 6114980 bytes, checksum: 07a301793e0522e5fb0084e12ee425fe (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-05-10 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Plants produce and emit a large array of volatile metabolites termed biogenic volatile organic compounds (BVOCs) as an integral part of primary and secondary metabolism. Monoterpenes are BVOCs from the largest family of plant natural products, the terpenoids. Despite orders of magnitude difference in atmospheric reactivity and great diversity in biological functioning, little is known about monoterpene speciation in tropical forests. Using thermal desorption-gas chromatography-mass spectrometry techniques, twelve volatile monoterpenes were identified and quantified in a central Amazon terra firma rainforest including the first ambient air observations of the highly reactive cis-β-ocimene and trans-β- ocimene. At the ecosystem scale, monoterpene mixing ratios in the ambient air were greatest at the top of the canopy where light and temperatures are greatest. Leaf level monoterpene emissions were found to be light dependent among the Amazon trees sampled in the field. However, during drought stress conditions that led to leaf senescence, leaf monoterpene emissions were found to be first light dependent followed by temperature dependent and an acted as an early indicator of leaf lipid peroxidation. Further, leaf monoterpene emissions revealed a strong non-linear relationship with net photosynthesis (Pn), dedicating up to 2% of Pn to monoterpene emissions at leaf temperatures up to 30ºC and continuing to rise as leaf temperatures increased. These results suggest that highly reactive monoterpenes may play important roles as antioxidants protecting photosynthesis in plants and serve as near-canopy sources of secondary organic aerosol precursors through atmospheric photooxidation reactions. / As plantas produzem e emitem uma grande variedade de metabólitos voláteis denominados compostos biogênicos orgânicos voláteis (BVOCs), como parte integrante do metabolismo primário e secundário. Monoterpenos são BVOCs de a maior família de plantas produtos naturais, os terpenóides. Apesar de diferenças das ordems de magnitude na reatividade atmosférica e grande diversidade em funcionamento biológico deles, pouco se sabe sobre a especiação dos monoterpenos em florestas tropicais. Usando tecnicas analiticas de desorpção termica-chromatografia gasosa-espetrometria (TD-GC-MS), doze monoterpenos voláteis foram identificados e quantificados numa floresta tropical de terra firma na Amazônia central, incluindo as primeiras observações no ar ambiente dos monoterpenos que são altamente reativos, cis-β-ocimeno e trans-β-ocimeno. Na escala do ecossistema, as taxas de mistura dos monoterpenos no ar ambiente foram maiores no topo do dossel onde a luz e as temperaturas são maiores. No nível das folhas, emissões dos monoterpenos foram dependente da luz para as avores foram amostradas em campo. No entanto, durante as condições de seca com estresses que levaram a senescência foliar, as emissões dos monoterpenos das folhas foram dependente primeiro da luz e depois a temperatura e agirem como um indicador da peroxidação lipídica folha. Além disso, as emissões dos monoterpenos das folhas revelou uma forte relação não-linear com fotossíntese líquida (Pn), dedicando-se a 2% do Pn para as emissões dos monoterpenos nas temperaturas das folhas até 30ºC e continuaram a aumentar com as temperaturas da folha. Estes resultados sugerem que os monoterpenos o que são altamente reativas podem ser importantes porque eles funçiõnam como antioxidantes que protegem a fotossíntese nas plantas e também podem ser fontes perto do dossel dos precursores dos aerossóis orgânicos secundários de fotooxidação na atmosfera.

Lungenkrebs ist die führende Todesursache unter den Krebstodesfällen. Vor allem in späten Stadien diagnostizierter Lungenkrebs ist schwer zu behandeln und mit einer schlechten Prognose vergesellschaftet. Daher ist es wünschenswert, die Tumorerkrankung möglichst früh zu diagnostizieren und idealerweise in einem Screening-Test finden zu können. In der hier vorliegenden Studie wollten wir die Frage klären, ob ein von der Firma Sony neu entwickeltes Messverfahren SonyNose-G2_SN8 für die Untersuchung von Atemluft und für die Diagnose von Lungentumoren geeignet ist. Für die Studie wurden Atemproben von insgesamt 124 Probanden gesammelt, davon 65 gesunde Studienteilnehmer, 43 Patienten mit histologisch gesichertem Lungenkrebs, 10 Patienten mit COPD und 6 Studienteilnehmern mit nicht lungenkrebsspezifischen Raumforderungen. Die Atemproben wurden innerhalb von 20 Minuten nach Probennahme analysiert. Als Referenz zur getesteten Atemprobe wurde ein Luftgemisch aus gereinigter Luft mit 50%-iger Luftfeuchtigkeit verwendet. Technisch handelt es sich bei der Auswertung um eine gaschromathographische Prüfmethode. Außerdem wurden zusätzliche Atemproben von den Patienten bzw. Probanden gesammelt, um diese mittels GC-MS-Messungen auf ihre volatilen organischen Bestandteile hin zu überprüfen. In den GC-MS-Untersuchungen der Atemproben konnten 263 verschiedene chemische Verbindungen identifiziert werden. Davon konnten 20 Substanzen ermittelt werden, die sich signifikant zwischen der Gruppe „Gesund“ und der Gruppe „Lungenkrebs“ unterschieden. Diese Substanzen könnten sich folglich als Marker für den Lungenkrebs eignen. Weitere Untersuchungen sind zur Überprüfung dieser Hypothese jedoch erforderlich. Nicht zuletzt aufgrund von Problemen mit der Stabilität einzelner Sensoren, war es mit der SonyNose-G2_SN8 nicht möglich, zwischen Lungenkrebs-Patienten, Patienten mit COPD und gesunden Probanden zu unterscheiden. Das getestete Gerät eignet sich also nicht für das Lungenkrebs-Screening im klinischen Einsatz. Auch nach der hier vorliegenden Untersuchung bleibt offen, ob Analyseverfahren zur Atemluftdiagnostik als Screening-Methode zur Früherkennung von Lungenkrebs grundsätzlich geeignet sind. Der Einsatz der gaschromatographischen-massenspektrometrischen Untersuchungsmethode ist für die Routinediagnostik derzeit noch zu zeitaufwendig und zu teuer. Die Identifikation möglicher krebsspezifischer volatiler organischer Verbindungen in der Atemluft von Patienten bleibt für die Forschung weiterhin eine offene und vielversprechende Thematik. / Lung cancer (LC) is the leading cause of cancer death worldwide. Results of therapeutic interventions are not satisfying because the disease is diagnosed in an advanced stage in more than 50% of the patients. Early diagnosis is limited by the fact that the disease usually develops asymptomatically and no screening methods are available. Previous studies have shown correlations between the chemical composition of the exhaled breath of an individual and the presence of LC. The Sony Materials Science Laboratory developed the "electronic nose" SonyNose-G2_SN8 for breath analysis that was tested in a clinical study to evaluate its suitability for LC diagnosis. The SonyNose was tested in a prospective clinical study (proof of concept study). The study was approved by the Etics committee of the University of Tuebingen [project 010/2012BO1). Breath samples from patients with COPD or suspected LC and from healthy individuals were collected. Inclusion criteria were males and females, aged 18-80 yrs, and signed informed consent. Exclusion criteria were suspected or confirmed malignant disease other than lung cancer, previous thoracic surgery and any medical interventions at the chest or the airways within the preceding 14 days. The study participants were classified into four groups: Group A- healthy; Group B-lung cancer; Group C-COPD; Group D-non malignant pulmonary nodule. The decision whether a patient was assigned to the cancer group B was made on the basis of histology of a tumour biopsy or the resected tumour after breath sample analysis. Breath samples were collected in gas sampling bulbs ("gas mouse") provided by Sony. Two gas mice were obtained per person. Reference bulbs were filled with a standardized gas. Additionally, cylindrical glass tubes that have been applied in a successful previous study of Prof. Walles were used for breath sampling. The gas mice were analyzed within 20 min at the Schillerhoehe Hospital using the SonyNose. The glass tubes were stored up and analyzed by gas-chromatography and mass spectrometry (GC-MS) at the Sony Materials Science Laboratory. Altogether, 124 participants were enrolled: 65 healthy individuals (group A), 43 patients with histologically confirmed LC (group B), 10 patients with COPD (group C) and 6 patients with non malignant pulmonary nodules. Breath sample analysis using the SonyNose revealed an instability of the sensor array. Some sensors had to be replaced in the course of the experiments. Intra-individual controls that were performed by testing the same patient repeatedly showed a very high intra-individual variation of the sensor signal and a very low reproducibility. GC-MS analysis were performed in only 27 individuals, because the R&D agreement was cancelled in the course of the study (Group A:9; Group B:11; Group C:1; Group D:6). In the analyzed breath samples, 263 different compounds were identified. In Group B 20 compounds showed a different distribution pattern than in other groups. Of these, 6 have been described as LC associated in previous studies. The small number of tested individuals restricts a conclusive assessment of the generated data. The SonyNose-G2_SN8 is not suitable for a clinical breath sample analysis in the technical configuration tested in our study. GC-MS measurements revealed 20 potential candidates for LC specific markers in the breath of patients. However, the small number of tested individuals limits the validity of our analysis.

<p>New energy resources that can replace petroleum diesel are needed and biodiesel may be an excellent substitute. During storage and use, biodiesel can oxidize and form peroxides, leading to degradation of the fuel. It is therefore important to determine the peroxide content of the fuel. In this thesis the triphenylphosphine method, which involves GC-MS analysis has been compared to the standard iodometric method which involves titration with sodium thiosulfate. Working standards were made to see how well the iodometric method worked and also in order to make a calibration curve in GC-MS. Aged samples were then analyzed. The results showed that both methods gave good linearity and repeatability with limits of detection (LOD) and quantification (LOQ) of 0,06 mM and 0 17-0,65 mM respectively. However, the iodometric method seemed more circumstantial since it needed a lot of solvents and different reagents. The triphenylphosphine method was on contrary very simple to use and did not require too much preparation work. The latter also showed better reproducibility. In conclusions, both methods can be used in evaluating the peroxide content of biodiesel, but the triphenylphosphine method has the advantages of higher simplicity and better reproducibility.</p>

Zugl.: Hohenheim, Univ., Diss., 2009

Many of the current analytical techniques originally developed to characterize conventional reservoir rocks and fluid cannot adequately measure shale and source rocks. An example of this is Retort, where it is not feasible to get sufficient fluid from source rock to make useful measurements. The primary interest of this thesis is the exploration of other analytical techniques, two of which are previously unused in the oil and gas industry. These are Thermal Gravimetric Analysis (TGA), Pyrolysis-Gas Chromatography-Mass Spectrometry (Py-GC-MS), and Nuclear Magnetic Resonance (NMR). The techniques proposed offer valuable insight into the properties of the rock. TGA gives accurate weight of a sample as temperature is increased, Py-GC-MS is useful for identifying exact molecules in vaporized fluid, and NMR can be used to characterize viscosity and hydrocarbon chain length. The methods using these techniques can be utilized to further confirm mineralogy of a sample, identify the fluid constituents and quantify their weight, analyze changes in a sample between two different states, and calculate the free fluid saturations of oil and gas in shales. Procedures and results for each of these are presented in this thesis to show methodology and give the reader an idea of its useful applications. / text

d-Limonene is a lipid-soluble bioactive food component found in citrus peel. It has demonstrated strong chemopreventive effects in rodent mammary, gastric, skin, liver, and lung cancers and is correlated with a significantly reduced risk for human squamous cell skin carcinoma. Because d-limonene is fat-soluble, it may have enhanced chemopreventive activity in fatty tissues such as breast. No previous methodology to quantify d-limonene in the adipose had been developed which significantly limited d-limonene tissue distribution research. For this research, an assay to extract d-limonene from adipose tissue and quantify with GC/MS was developed and validated. Linear calibration curves were established over the range of 0.0-2,526 ng d-limonene. Extraction recovery was 80%. Satisfactory within day precision (RSD 6.75 to 9.56%) and accuracy (% difference of 2-4%) were achieved. This sensitive, accurate, and precise assay to quantify d-limonene in adipose can be used for future human or animal fatty tissue deposition studies.

Polycyclic aromatic hydrocarbons (PAHs) are toxic and carcinogenic environmental contaminants originating from different sources; petrogenic, pyrogenic or biogenic. Depending on the source of contamination there will be different ratios of PAHs and the effects on the environment will differ. Petrogenic sources will be higher in concentration of alkyl substituted PAHs (APAHs) while pyrogenic sources will be higher in parent PAHs. In the present study a GC/MS method was developed to separate and calibrate PAHs, dibenzothiophenes and alkyl substituted PAHs in a mix containing 49 standards. The method was able to differentiate between PAHs and APAHs with the same mass number; up to six different compounds with the same mass number was separated. The developed method was used to analyse six different soil samples from various contamination sites. PAHs, APAHs and dibenzothiophenes were identified and quantified in all samples. In order to establish the source of contamination, the distribution pattern, the ratio between different PAHs, and the ratio between APAHs and parent PAHs were used. There was a higher ratio of APAHs/PAHs and a lower ratio between the parent PAHs in the soil samples from sites contaminated with oils compared to the other samples, indicating petrogenic source. / Polycykliska aromatiska kolväten (PAH) är giftiga och cancerframkallande miljögifter som härstammar från olika källor; petrogena, pyrogena eller biogena. Olika föroreningskällor kommer att ha olika förhållanden av PAH och effekterna på miljön kommer att skilja. Petrogena källor innehåller högre koncentrationer av alkylsubstituerade PAH (APAH) medan pyrogena källor kommer att ha högre koncentration av PAH. I denna studie har en GC/MS-metod utvecklats för att separera och kalibrera PAH, dibensotiofener och alkylsubstituerade PAH i en blandning innehållande 49 standarder. Metoden kunde skilja mellan PAH och alkylsubstituerade PAH med samma masstal; upp till sex olika föreningar med samma masstal särskildes. Den utvecklade metoden användes för att analysera sex olika jordprover från olika föroreningsplatser. PAH, APAH och dibensotiofener identifierades och kvantifieras i samtliga prover. För att fastställa föroreningskällan användes fördelningsmönstret för APAH och PAH, förhållandet mellan olika PAH och ration mellan APAH och PAH. Det fanns en högre kvot APAH/PAH i jordprover från områden som var förorenade med olja, vilket indikerar på petrogena föroreningskällor.