Per- and poly- fluoroalkyl substances (PFASs) are a group of manmade substances synthesised for more than 60 years. Due to their specific properties, PFASs have been widely used for industrial applications including: electronics, textiles, food packaging, flame retardant formulae and laboratory tools, among others. However, it was during the last fifteen years ago that interest for this group of compounds as environmental pollutants was initiated. Due to their high release levels into the environment, stability and accumulation, PFASs have been found ubiquitous in the environment and in biota. In this context, the main goal of this doctoral PhD thesis was the study of the occurrence, fate and behaviour of a wide range of PFASs in the environment, in food and, finally, in some human matrices. In addition, the physicochemical properties studies and the aerobic biodegradation experiments of 3 perfluoroalkyl phosphonic acids were also evaluated. Therefore, the first specific objective was the development of different analytical methods to study a wide range of PFASs in selected matrices. The analytical methods have been based on the use of on-line chromatography and off-line extraction, followed by liquid chromatography coupled to tandem mass spectrometry. These methods have been employed to assess the presence of PFASs in different type of waters from different steps along the water cycle, and also in fish and other food commodities. And finally, the PFAS accumulation in human samples was studied in cord blood and breast milk. This work is divided into six chapters. The first chapter is the general introduction and the objectives of this PhD Thesis. In the introduction, different aspects are revised, such as synthesis and global production, environmental fate and occurrence, human accumulation, toxicology, regulations and future trends. Chapters 2, 3, 4 and 5 present the experimental work undertaken during this research. Each chapter has been divided into a specific introduction, results (presented through the corresponding publications) and discussion. Part of the results contained in Chapters 2 and 5 correspond to the experimental work carried out in the laboratory of Prof. Dr. Thomas P. Knepper (Hochschule Fresenius, Idstein, Germany) during a four month research internship, a part of the European Doctoral Programme. Chapter 6 contains the general conclusions. Finally, a small summary in Catalan is presented. The cited literature and indexes for tables and figures can be found at the end of this work, as well as the list of publications produced along the duration of the pre-doctoral studies, but which are not presented in this thesis. The distribution of the publications included in this Thesis is the following: Chapter 2: Environmental occurrence Publication 1: “Analysis of perfluoroalkyl substances in waters from Germany and Spain.” Llorca, M., Farré, M., Picó, Y., Müller, J., Knepper, T. P. and Barceló, D. (2012). Science of The Total Environment, 431(0): 139-150. Publication 2: “Analysis of perfluorinated compounds in sewage sludge by pressurized solvent extraction followed by liquid chromatography–mass spectrometry.” Llorca, M; Farré, M; Picó, Y; Barceló,D; (2011). Journal of Chromatography A, 1218 (30) 4840-4846. Publication 3: “Fate of a broad spectrum of perfluorinated compounds in soils and biota from Tierra del Fuego and Antarctica.” Llorca, M., Farré, M., Tavano, M. S., Alonso, B., Koremblit, G. and Barceló, D. (2012). Environmental Pollution 163(0): 158-166. Chapter 3: PFASs in food Publication 4: “Development and validation of a pressurized liquid extraction liquid chromatography-tandem mass spectrometry method for perfluorinated compounds determination in fish.” Llorca, M., Farré, M., Picó, Y., and Barceló, D. (2009). Journal of Chromatography A 1216(43): 7195-7204. Publication 5: “Study of the performance of three LC-MS/MS platforms for analysis of perfluorinated compounds.” Llorca, M., Farré, M., Picó, Y., and Barceló, D. (2010) Analytical and Bioanalytical Chemistry 398(3): 1145-1159. Publication 6: “Infant exposure of perfluorinated compounds: Levels in breast milk and commercial baby food.” Llorca, M., Farré, M., Picó, Y., Teijón, M. L., Álvarez, J. G. and Barceló, D. (2010). Environment International 36(6): 584-592. Chapter 4: PFASs accumulation in humans Publication 7: “Analysis of perfluoroalkyl substances in cord blood by turbulent flow chromatography coupled to tandem mass spectrometry.” Llorca, M., Pérez, F., Farré, M., Agramunt, S., Kogevinas, M. and Barceló, D. (2012). Science of The Total Environment 433(0): 151-160. / Les substàncies per- i poli- fluorades (PFASs) són d’origen antropogènic. Aquest ampli grup de compostos s’ha sintetitzat durant més de 60 anys. Degut a les seves propietats específiques s’utilitzen encara en l’actualitat en diferents aplicacions industrials tals com: electrònica, recobriments tèxtils, embolcall d’aliments, escumes ignífugues i material de laboratori entre d’altres. No obstant, no ha estat fins els últims 15 anys quan a aquests compostos se’ls ha començat a considerar contaminants ambientals. Degut als nivells que es troben en el medi ambient, l’estabilitat i l’acumulació que presenten, aquests anàlits tenen una distribució global en el medi i en biota. En aquest context, el principal objectiu d’aquesta tesi doctoral ha estat l’estudi de la presència, destí i comportament d’un ampli grup de PFASs (13 àcids prfluoroalquílics, 4 perfluorosulfats, 1 perfluorosulfonamida i 3 àcids perfluorofosfònics) en el medi ambient, aliments i, finalment, en algunes matrius humanes. En paral•lel a l’estudi dels esmentats treballs, s’han realitzat en experiments per determinar algunes de les propietats fisicoquímiques i la possible biodegradació aeròbica de 3 àcids perfluorofosfònics. Per aquest motiu, el primer objectiu específic ha esta el desenvolupament de diferents mètodes analítics per a l’estudi d’aquests anàlits en les matrius seleccionades. Els mètodes analítics desenvolupats han inclòs tant mètodes d’extracció fora de línia com de cromatografia en línia, seguit d’una separació per cromatografia líquida acoblada en tàndem a l’espectrometria de masses. Aquests mètodes han estat utilitzats per al posterior estudi de la presència de PFASs en diferents mostres d’aigua provinents de tot el cicle de l’aigua així com peix i altres aliments. Finalment, l’acumulació de PFASs en humans s’ha estudiat a partir de l’anàlisi de mostres de sang de cordó umbilical i llet materna.

Mercury (Hg) is naturally present in the Earth’s crust, however the historical use of this metal by the human being has spread and increased its presence in the environment. Both inorganic and organic species can be found in aquatic ecosystems, which are very sensitive to Hg pollution. In anoxic waters and sediments, sulphate-reducing bacteria can convert inorganic Hg into methylmercury (MeHg), a very toxic organic form which has the ability to bioaccumulate and biomagnify throughout trophic chains. Thus, to assess the risk associated to Hg pollution, the development of techniques to monitor Hg levels in water is necessary, as well as investigating MeHg elimination pathways. In this doctoral thesis, two aspects related to the biogeochemical cycle of Hg in freshwater were addressed. On one hand, a passive sampling technique –Diffusive Gradients in Thin films (DGT)– was developed both for determination of total Hg (THg) and MeHg in freshwater. Apart from providing a time-average Hg concentration, these samplers are able to measure the labile fraction of Hg, since they supposedly mimic biological membranes. Thus, the DGT technique is considered a good monitoring tool to estimate the bioavailability of Hg in water. On the other hand, MeHg photodegradation in freswhwaters dominated by dissolved organic matter (DOM) was studied. Regarding the DGT technique, several preliminary tests were carried out both at the laboratory and in the field to test the validity of a commercial type of samplers to measure the labile dissolved Hg in continental waters. Later, the performance of this commercial type was compared to that of two in-house manufactured samplers; both of them with the same receiving gel consisting of a resin with 3-mercaptopropyl groups embedded in a polyacrylamide gel, but one with an agarose gel (A-DGT) and the other with polyacrylamide gel (P-DGT) as the diffusive layer. The uptake kinetics of Hg(II) and MeHg, both in the absence and in the presence of DOM, were studied. The diffusion coefficient, D, of Hg in the DGT diffusive layer varied among Hg species and also depended on the absence/presence of DOM in the solution. This confirms the need to use the Hg species of interest and simulate the characteristics of the water to be sampled when performing the DGT calibration if the aim is to accurately measure the labile Hg fraction. The P-DGT was chosen as the most appropriate to determine both THg and MeHg in natural waters. Thereby, this type of sampler was used in a case study to assess the removal, methylation and lability of Hg(II) in a experimental scale plant for wastewater treatment consisting in several constructed wetlands with different conformation in series. With respect to the MeHg photodegradation issue, this phenomenon was studied in waters from a lake-wetland gradient in the boreal Sweden. The influence of DOM on this process by attenuating light, forming reactive oxygen species and binding MeHg to its thiol groups to form complexes, was examined. It was observed that the desmethylation rate constant (kpd Full Spectrum) varied significantly among the three studied waters, but the wavelength-specific rate constants (kpdPAR, kpdUVA and kpdUVB) were indistinguishable. Therefore, kpd PAR, kpd UVA and kpd UVB can be considered universal, at least in waters dominated by DOM and in which MeHg is complexed by organic thiols, if the photon fluxes of PAR, UVA and UVB radiation are separately determined and the wavelength-specific light attenuation by DOM is corrected for. Furthermore, the relationship between the photodegradation and bioavailability of MeHg was examined in an experiment involving different types of natural and artificial freshwater, but no apparent connection was observed between them. / En aquesta tesi doctoral s'aborden dos aspectes relacionats amb al cicle biogeoquímic del Hg en aigües continentals. Per una banda, es va desenvolupar un sistema de mostreig passiu denominat gradients de difusió en capa fina (DGT), per la determinació del Hg total i del MeHg en fase aquosa. Aquests mostrejadors proporcionen la concentració mitjana de Hg durant el temps de mostreig i mesuren la fracció làbil de Hg. Per tant, la tècnica de DGT pot ser considerada una bona eina per avaluar la biodisponibilitat de Hg a l’aigua. D'altra banda, es va estudiar la fotodegradació de MeHg en aigües continentals. Pel que fa a la tècnica DGT, es van dur a terme diverses proves preliminars tant al laboratori com en el camp per provar la validesa d'un tipus comercial de mostrejador per mesurar el Hg dissolt i col•loidal làbil en aigua dolça. Aquest es va comparar amb dos tipus de mostrejadors DGT manufacturats al laboratori (A-DGT i P-DGT). Es van estudiar les cinètiques d’acumulació de Hg(II) i MeHg tant en absència com en presència de DOM. El P-DGT va ser escollit com el més apropiat per determinar ambdós THg i MeHg en aigües naturals i va ser utilitzat en un estudi de cas per avaluar l'eliminació, metilació i labilitat de Hg(II) en una aiguamoll construït a escala experimental pel tractament d’aigües residuals urbanes. La fotodegradació de MeHg va ser estudiada en aigües d'un gradient llac-aiguamoll en la Suècia boreal; i es va evaluar la influència de DOM en el procés. Es va observar que la constant de velocitat de fotodesmetilació (kpd Full Spectrum) va variar significativament entre les aigües estudiades, però les constants específiques per a cada longitud d'ona (kpdPAR, kpdUVA and kpdUVB) van ser indistingibles. Per això, kpdPAR, kpdUVA and kpdUVB poden ser considerades universals en aigües amb un alt contingut en DOM i on el MeHg estigui complexat per grups tiol orgànics. Finalment, amb la utilització de la tècnica DGT es va estudiar la possible influència que pot existir entre la fotodegradació i la biodisponibilitat de MeHg en diversos tipus d'aigues dolces naturals i artificials, però no es va observar cap connexió aparent entre elles.

Tesi realitzada a l'Institut de Diagnosi Ambiental i Estudis de l'Aigua (IDAEA - CSIC) / In the past two decades we witnessed a decrease in both the number of oil spill incidents, and of the quantity of oil released in these incidents, which led to a diminished interest for basic oil spill science. With the introduction of more stringent oil spill legislation, much of the spill response, assessment and restoration activities were passed to governmental agencies and other stakeholders. Their capabilities were perhaps sufficient to deal with the most frequently occurring small-scale spills, however, recent large, catastrophic incidents such as the sinking of Prestige in 2002, or the Deepwater Horizon blowout in 2010, renewed the need for fundamental science in order to be able to fully understand and estimate the scope of the impacts such spills can have on the environment, economy and society. This is particularly important in the context of new explorations and discoveries of hydrocarbon resources in pristine regions such as Arctic, where extreme weather and the lack of infrastructure emphasize even more the need for a comprehensive assessment of all of the possible effects the future oil production could cause. The objectives of this thesis were set to provide new approaches and methodologies, and to improve and reevaluate the previously existing ones, in a way which can contribute to this comprehensive and proactive strategy. Their scope is comprehensive because it covers all the important aspects of marine oil spills – the sources, environmental fate and possible toxic effects. In addition, particular relevance of this thesis is drawn from the fact that the studies presented here include the investigation of real major oil spills (Prestige, DWH), and of a broad range of oils and oil products that are currently produced and transported worldwide. In order to fulfill the abovementioned general objectives, the following specific objectives had to be accomplished: Firstly, a physicochemical database of frequently transported crude and refined oils was created using elemental analysis, thin-layer liquid chromatography (TLC) with flame ionization detector (FID) analysis of principal oil compound groups, gas chromatography-mass spectrometry (GC-MS) fingerprinting of polycyclic aromatic hydrocarbons (PAHs) and biomarkers, and available oil assays. This database was then applied to assess their possible fate in the case of a spill, and to model three spill scenarios in different European regional seas using ADIOS2 software from NOAA (National Oceanic and Atmospheric Administration). Fingerprints of selected oils were assessed and statistically compared to discover the most relevant compositional differences that could facilitate the identification of oil spill sources. Secondly, the GC-MS methodology used to create the fingerprint database of selected oils was evaluated in an international interlaboratory ring test. The objective was to test the capability of this fingerprinting methodology to identify the type and source of weathered (biodegraded) oil samples. Thirdly, the weathering of oil samples from Prestige and Deepwater Horizon spills, in particular the photooxidation, was studied. Samples weathered in field and in laboratory experiments were analyzed using TLC-FID, GC-MS, comprehensive two dimensional gas chromatography (GCxGC) with FID, and Fourier transform infrared spectrometry (FT-IR) to discover compositional changes on the bulk level as well as on the molecular level. PAHs and triaromatic steranes (TAS) were of particular interest, as well as the effects of the photooxidation on the robustness of the oil fingerprinting methodology. Finally, the effects of selected fresh and weathered (evaporated, photooxidized) crude and refined oils were studied, using the effect-directed analysis (EDA). The samples were sequentially fractionated using open-column liquid chromatography and normal-phase semipreparative HPLC, and the obtained fractions were subjected to bioassays to test their AhR agonist and AR antagonist activity. The most active fractions were then analyzed using GCxGC coupled to time-of-flight mass spectrometry (TOFMS), and this data was related to bioassay results using N-way partial least square (N-PLS) chemometric model, in order to identify the compounds responsible for the observed effects. / A pesar de las tendencias positivas en las últimas décadas, los vertidos ocasionados por la exploración, extracción y transporte de petróleo siguen siendo una importante amenaza para los ecosistemas marinos y especialmente costeros. Esta Tesis se ocupa de todos los aspectos importantes sobre los vertidos marinos de petróleo: el origen, el destino ambiental y sus posibles efectos. Para permitir su comprensión global, se utilizaron diferentes metodologías complementarias. En primer lugar, se ha creado una base de datos físico-químicos de diferentes petróleos (crudos y refinados) que se transportan frecuentemente usando el análisis elemental, la cromatografía en capa fina (TLC) acoplada a un detector de ionización de llama (FID) de los principales grupos de compuestos de petróleo, la toma de huellas químicas de los hidrocarburos aromáticos policíclicos (HAP) y los biomarcadores mediante cromatografía de gases acoplada a espectrometría de masas (GC-MS), y ensayos de petróleo disponibles. A continuación, se aplicó esta base de datos para evaluar su posible destino en el caso de un vertido, y para modelar tres escenarios de vertidos en diferentes mares regionales europeos usando el software ADIOS2 de la Administración Nacional Oceánica y Atmosférica (NOAA). Las huellas químicas de los petróleos seleccionados fueron evaluadas y comparadas estadísticamente para investigar las diferencias de composición más relevantes que podrían facilitar la identificación del origen de vertido. En segundo lugar, la metodología de GC-MS utilizada para crear la base de datos de las huellas químicas de los petróleos seleccionados se ha evaluado en una prueba interlaboratorio internacional. El objetivo fue investigar la capacidad que tiene esta metodología de toma de huellas químicas para identificar el tipo y el origen de las muestras envejecidas (biodegradadas) de petróleo. En tercer lugar, se ha estudiado el envejecimiento de las muestras de petróleo de los vertidos de Prestige (2002) y de la plataforma Deepwater Horizon (2010), en particular, debido a la fotooxidación. Se analizaron muestras envejecidas en el campo y en experimentos de laboratorio mediante TLC-FID, GCMS, cromatografía de gases bidimensional integrada (GCxGC) acoplada a un FID, y espectroscopia infrarroja por transformada de Fourier (FT-IR) para investigar los cambios de composición tanto a nivel global como a nivel molecular. Los HAP y esteranos triaromáticos fueron de especial interés, así como los efectos de la fotooxidación en la robustez de la metodología de toma de huellas químicas de petróleo. Finalmente, se estudiaron los efectos de las muestras no tratadas y envejecidas (evaporadas, fotooxidadas) de los petróleos crudos y refinados seleccionados, utilizando el análisis dirigido por los efectos tóxicos (EDA). Las muestras se fraccionaron secuencialmente usando la cromatografía líquida en columna abierta y la cromatografía líquida de alta eficacia (HPLC) semipreparativa en fase normal. Las fracciones obtenidas se sometieron a bioensayos para investigar su actividad agonista de los receptores AhR y la actividad antagonista de los receptores AR. En el siguiente paso, las fracciones más activas fueron analizadas mediante GCxGC acoplada a espectrometría de masas en tiempo de vuelo (TOFMS), y estos datos se relacionaron con los resultados de los bioensayos utilizando un modelo quimiométrico de regresión por mínimos cuadrados parciales en N direcciones (N-PLS), con el fin de identificar los compuestos responsables de los efectos observados.

Los antibióticos se usan en medicina veterinaria para curar enfermedades, para prevenirlas (uso profiláctico) y como promotores del crecimiento, aunque este último uso está prohibido en la Unión Europea desde 2006. La presencia de residuos de antibióticos en muestras alimentarias de origen animal supone un riesgo para la salud de los consumidores. Estos residuos pueden provocar problemas de alergias y toxicidad en individuos sensibles y generar resistencia bacteriana. Con el fin de proteger la seguridad alimentaria del consumidor, la UE estableció en la Regulación 2377/90/EC, unos límites máximos de residuos (MRL), es decir, concentraciones máximas de fármaco que pueden estar presentes en los alimentos de origen animal, para que sean seguros para el consumo humano. Durante esta tesis doctoral se han desarrollado y validado cuatro métodos multiresiduo para la determinación de quinolonas y β-lactamas (penicilinas y cefalosporinas) en leche de vaca siguiendo la normativa Europea 657/2002 y la guía de la FDA. Los métodos optimizados se basan en distintos tratamientos de muestra (extracción en fase sólida (SPE), microextracción líquido líquido dispersiva (DLLME) y extracción asistida por ultrasonidos seguida de una extracción en fase sólida dispersiva (USE-d-SPE)) y se analizaron por cromatografía de líquidos acoplada a la espectrometría de masas en tándem (LC-MS/MS). Con el fin de que la leche pueda ser apta para el consumo humano, es necesario que pase un determinado tiempo entre la última administración del antibiótico al animal y la recogida de la leche, con el fin de que pueda eliminarse del organismo los antibióticos y sus metabolitos. Si no se respeta este tiempo, la leche procedente de vacas medicadas con antibióticos puede contener residuos de éstos, además de compuestos resultantes de la metabolización en el animal. Por otro lado, también requiere que se eliminen los microorganismos patógenos a través de la aplicación de determinados tratamientos térmicos. Es de especial interés el estudio de la metabolización de los antibióticos y como pueden afectar los tratamientos térmicos sobre éstos, dando lugar a productos de transformación (TPs). Al igual que los antibióticos administrados, tanto los metabolitos como los TPs pueden provocar efectos adversos como toxicidad, alergias y en el caso de mantener la actividad antibacteriana, resistencia bacteriana. Así, en el segundo bloque de esta tesis, se ha estudiado la metabolización de diferentes antibióticos (ENR, CIP, DIF, SAR, AMOX, PENG, PIR y TIO), y la influencia de los tratamientos térmicos en la estructura de los antibióticos. Para conseguir este objetivo se han analizado diferentes muestras de leche fortificadas con quinolonas y β-lactamas, y también se han estudiado muestras de leche procedentes de animales medicados con enrofloxacina (ENR) y benzilpenicilina (PENG) y recogidas durante los tres días de tratamiento farmacológico y durante los cuatro días posteriores a la finalización de éste. Las muestras se analizaron mediante LC-ToF y LC-LTQ-Orbitrap. Se han determinado y caracterizado más de 60 TPs y metabolitos, siendo más de la mitad descritos por primera vez. / The presence of antibiotic residues in food samples from animal origin is a risk to consumer health. These residues can cause allergies and toxicity problems in sensitive individuals and create bacterial resistance. In order to protect food consumer safety, the EU established in Regulation 2377/90/EC, a maximum residue levels (MRL). During this PhD thesis four multi-residue methods for the determination of quinolones and β-lactams (penicillins and cephalosporins) in cow's milk according to the European regulation 657/2002 and FDA guidance have been developed and validated. Optimized methods are based on various sample treatments (solid phase extraction (SPE), liquid dispersive liquid microextraction (DLLME) and ultrasound assisted extraction followed by a dispersive solid phase extraction (USE-d-SPE)) and analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS / MS). If a cow medicated is milked too soon, before all antibiotic and its metabolites are eliminated from the body, residues of the administered antibiotic and their metabolites can be found in the milk. These can pass to humans through the food chain causing health problems such as allergies, toxicity and resistant bacterial strains. On the other hand, milk is treated thermally (pasteurisation and sterilization) before human consumption to eliminate pathogens microorganisms. These processes can affect the residues of antibiotics and their metabolites modifying their structures and given several transformation products (TPs). Thus, in the second part of this thesis, we have studied the metabolism of different antibiotics (ENR, CIP, DIF, SAR, AMOX, PENG, PIR and TIO) and the influence of heat treatment on the structure of antibiotics. To achieve this goal different samples of milk fortified with quinolones and β-lactams have been analyzed. Samples of milk from animals medicated with enrofloxacin (ENR) and benzylpenicillin (PENG) and collected during the three-day of pharmacologic treatment and during the four days following the end of it have also studied. Samples were analyzed by LC-ToF and LC-LTQ-Orbitrap. They have been identified and 60 characterized TPs and metabolites, over half first described

Apart from the geological controls that can cause As mobilization in groundwater in the Bengal Delta Plain, local anthropogenic factors may also contribute to some extent. Investigations showed that As(III) get enriched in the groundwater after the monsoonal season. This could be due to the enhanced reducing conditions in the aquifer post-monsoonal recharge. The larger inorganic colloids were responsible to scavenge As(III) and the smaller organic/organo-metallic colloids were found to scavenge As(V). A study was carried out to improve the Solar Oxidation and Removal of Arsenic (SORAS) for rural population, using tomatoes instead of lemons, showing that tomato was more efficient and cost-effective than lemon or lime. A novel technique combining hollow fiber liquid phase microextraction (HF-LPME) with Total Reflection X-Ray Fluorescence (TXRF) for the determination and speciation of As in groundwater was developed. The results in the laboratory samples were found encouraging and applied to natural samples successfully / Además de los controles geológicos, los factores antropogénicos contribuyen también a la movilización de arsénico en el agua subterránea del Bengal Delta Plain. La concentración de As(III) aumenta después de la temporada del monzón, debido a las condiciones más reductoras en el acuífero. El As(III) se encuentra asociado a coloides inorgánicos de mayor tamaño mientras que los coloides orgánicos/organometálicos más pequeños contienen As(V). Se llevó a cabo un estudio para mejorar el proceso SORAS (Solar Oxidation and Removal of Arsenic) comparando diferentes fuentes de citrato, y demostrando que el tomate es más eficiente y económico que el limón o la lima. Se ha desarrollado un método novedoso para la determinación y especiación de As basado en microextracción en fase líquida en fibra hueca (HF-LPME) combinados con fluorescencia de rayos X con reflexión total (TXRF), y que ha sido aplicado con éxito en diferentes muestras de aguas naturales

En aquesta tesi doctoral, realitzada a la Secció de Cromatografia del Departament de Química Analítica de l’Institut Químic de Sarrià (IQS), s’ha desenvolupat, optimitzat, validat i implementat un mètode analític (HPLC-UV) per portar a terme la determinació d’aldehids i cetones precursors d’ozó troposfèric, continguts en cartutxos de sílice impregnats amb 2,4-dinitrofenilhidrazina, en mostres procedents d’emissions de vehicles. L’estudi de la retenció cromatogràfica de les 2,4-dinitrofenilhidrazones (DNPH) de diversos compostos carbonílics mitjançant dos mètodes HPLC en mode isocràtic, amb dues fases estacionàries ortogonals (octadecilpolietoxisilà i cianopropil), ha permès obtenir un mètode de classificació d’aquests compostos per famílies, basat en les diferències dels seus índexs de retenció entre ambdues columnes. S’han aplicat metodologies QSRR (relacions quantitatives entre estructura química- retenció cromatogràfica), tant lineals com no lineals, al mètode per a la determinació d’aldehids i cetones en mostres d’emissions de vehicles. Els models de predicció establerts han permès acotar el número de compostos candidats a correspondre a alguns compostos desconeguts apareguts al llarg de l’anàlisi de mostres d’emissions de vehicles. Aquesta informació ha estat de gran valor per tal d’aconseguir identificar aquests compostos mitjançant UPLC®-MS/MS. Aquesta tesi s’ha realitzat en un entorn de Qualitat, dins les bases dels sistemes ENAC 17025 i ISO 9001. / En esta tesis doctoral, realizada en la Sección de Cromatografía del Departamento de Química Analítica del Instituto Químico de Sarrià (IQS), se ha desarrollado, optimizado, validado e implementado un método analítico (HPLC-UV) para llevar a cabo la determinación de aldehídos y cetonas precursores de ozono troposférico, contenidos en cartuchos de sílice impregnados con 2,4- dinitrofenilhidrazina, en muestras procedentes de emisiones de vehículos. El estudio de la retención cromatográfica de las 2,4-dinitrofenilhidrazonas (DNPH) de diversos compuestos carbonílicos, mediante dos métodos HPLC en modo isocrático, empleando dos fases estacionarias ortogonales (octadecilpolietoxisilano y cianopropilo), ha permitido obtener un método de clasificación de estos compuestos por familias, basado en las diferencias de los índices de retención entre ambas columnas. Se han aplicado metodologías QSRR (relaciones cuantitativas entre estructura química- retención cromatográfica), tanto lineales como no lineales, al método para la determinación de aldehídos y cetonas en muestras de emisiones de vehículos. Los modelos de predicción establecidos han permitido acotar el número de compuestos candidatos a corresponder a algunos compuestos desconocidos aparecidos a lo largo del análisis de muestras de emisiones de vehículos. Esta información ha sido de gran valor para conseguir identificar estos compuestos mediante UPLC®-MS/MS. Esta tesis se ha realizado en un entorno de Calidad, dentro de las bases de los sistemas ENAC 17025 e ISO 9001. / This thesis has been conducted at de Chromatography Section in the Department of Analytical Chemistry of IQS (Institut Químic de Sarrià). An HPLC-UV method for the analysis of aldehydes and ketones (tropospheric ozone precursors) contained in silica 2,4-dinitrophenylhidrazine impregnated cartridges has been developed, optimized, validated and implemented in vehicle emissions samples. The chromatographic retention of 2,4-dinitrophenylhydrazones (DNPH) of different carbonyl-compounds using two HPLC isocratic methods working with two orthogonal stationary phases (octadecylpolyethoxysilane and cyanopropyl) has been studied. Differences between the retention indexes obtained for each column have been used for classifying carbonyl-DNPH into compounds families. Linear and non-linear quantitative structure-retention relationships (QSRR) methods have been applied to the HPLC-UV method for the determination of aldehydes and ketones in vehicle emission samples. The resulting prediction models allowed the screening of the most probable carbonyl-DNPH derivative candidates that correspond to unknown compounds detected in automotive emission samples. This information has been useful for their identification by UPLC®-MS/MS. This thesis has been carried out in ENAC 17025 and ISO 9001 quality management systems.

The main objective of this thesis was to synthesise and apply new polymeric sorbents to obtain good recoveries in the solid-phase extraction (SPE) of organic polar pollutants in real water samples. The synthesised sorbents were used in SPE on-line coupled to high-performance liquid chromatography in order to establish analytical methods which can determine these pollutants in tap and river water samples.These synthesised sorbents were several chemically modified polymeric sorbents obtained by introducing different polar functional groups in the chemical structure of a polystyrene-divinylbenzene resin. Thus, the surface of these polymers was more hydrophilic and the polar compounds could be more strongly retained in these sorbents than in the unmodified resin and other commercially available sorbents. Nevertheless, the increase in the capacity of retention of the chemically modified sorbents also implied that more interferences from the matrix were retained, such as humic substances. These substances appear in the chromatograms as an initial broad band which hampers the determination of the more polar analytes. For this reason, a method based on the addition of sodium sulphite to the sample was developed to decrease this matrix interference.The synthesis of molecularly imprinted polymers was also studied. These polymers were prepared using 4-nitrophenol as the template and the non-covalent method, and allowed 4-nitrophenol to be selectively extracted from real water samples. It was also demonstrated the possibility to use these polymers as sorbents in the SPE on-line coupled to liquid chromatography. / L'objectiu fonamental de la present Tesi Doctoral ha estat el desenvolupament i aplicació de nous sorbents polimèrics per tal d'obtenir bones recuperacions en l'extracció en fase sòlida (SPE) de contaminants orgànics polars presents en mostres d'aigua. Aquests sorbents han estat emprats en la SPE acoblada en línia a la cromatografia de líquids d'alta resolució (HPLC) per tal d'establir mètodes d'anàlisi d'aquests contaminants en aigües de diferent procedència.Existeixen molts sorbents comercialment disponibles per a realitzar el procés de SPE, però la majoria donen molt baixes recuperacions pels analits més polars i per tant aquests compostos són difícils de determinar a baixos nivells. Una altra important limitació d'aquests sorbents és la seva manca de selectivitat, fet especialment important quan s'analitzen mostres mediambientals d'elevada complexitat. Per tal d'obtenir unes recuperacions més elevades pels analits polars que amb els sorbents convencionals, en la present tesi s'han desenvolupat nous sorbents polimèrics químicament modificats mitjançant la reacció de Friedel-Crafts. Aquesta reacció ha permès la introducció de diferents grups funcionals polars una la reïna de poliestirè-divinilbenzè (PS-DVB). La seva introducció ha augmentat la polaritat de la superfície de la reïna i d'aquesta manera els analits polars han quedat més retinguts en aquests sorbents químicament modificats que en la reïna de partida. Aquests nous sorbents s'han comparat favorablement amb altres sorbents comercials de diferents tipus en l'extracció de diversos compostos fenòlics i plaguicides polars.També s'ha avaluat l'efecte de diferents propietats físiques (àrea superficial i diàmetre de partícula i porus) de la reïna de partida sobre el grau de funcionalització en la modificació química del PS-DVB amb el grup o-carboxibenzoil. S'ha obtingut un grau de modificació similar amb tres reïnes i per tant s'ha demostrat que les diferents propietats físiques de les reïnes emprades no tenen efecte sobre el grau de funcionalització amb el grup o-carboxibenzoil. No obstant, s'han obtingut unes recuperacions més grans pels analits més polars amb la reïna que té una àrea superficial més elevada degut a la possibilitat d'un major nombre d'interaccions -.Degut a l'increment de capacitat de retenció dels polímers químicament modificats apareix l'inconvenient que més interferències de la matriu, com ara les substàncies húmiques, queden retingudes en aquests sorbents. Les substàncies húmiques formen part de la matèria orgànica dissolta en l'aigua i apareixen en els cromatogrames en forma de banda inicial ampla que dificulta la determinació dels analits que elueixen primer, és a dir, els analits més polars. En aquesta tesi s'ha desenvolupat un tractament químic de la mostra amb sulfit sòdic que permet reduir considerablement aquesta banda i per tant facilita la determinació dels compostos més polars sense interferència dels àcids húmics.En la recerca de sorbents més selectius per a la SPE, l'experimentació d'aquesta tesi s'ha encaminat cap als sorbents polimèrics amb empremta molecular (MIP). Així doncs, s'ha sintetitzat un nou tipus de sorbent selectiu que consisteix en un polímer amb empremta molecular pel 4-nitrofenol. L'existència d'aquesta empremta molecular pel 4-nitrofenol s'ha demostrat fent un estudi de l'especificitat d'aquest MIP per a l'extracció selectiva del 4-nitrofenol a partir d'una mescla de compostos fenòlics. L'estudi demostra la possibilitat d'emprar un polímer amb empremta molecular com a sorbent en la SPE acoblada en línia a HPLC. Per tal d'obtenir una extracció selectiva del 4-nitrofenol s'han optimitzat alguns paràmetres crítics en el procés de SPE. Aquest sorbent també ha estat avaluat i comparat favorablement amb sorbents comercials en l'extracció de mostres d'aigua del riu Ebre.

The main scope of this doctoral thesis was the evaluation of micro- and non-destructive techniques applied to artwork characterization. The need to study capabilities and limitations of these techniques arises from their increased use in the field of Cultural Heritage, without sufficient previous evaluation. Oil paintings, photographs and a large metal alloy object were investigated as representatives of three important artwork categories. Chapter 1 is an overview of the material properties of the artwork types investigated. Chapter 2 presents the study of the detection limits and the evaluation of the reproducibility of SEM-EDS and micro-FTIR in the application to paint layer investigation. Despite the good quality of the obtained spectra and the high sensitivity of these techniques, the low amount of material and the distribution of the different compounds across the sample made it difficult to obtain representative results. These problems could partially be overcome by analysing large areas rather than spots for SEM-EDS and performing replicates on different points of the specimen for micro-FTIR. Moreover, the capacities and limitations of midIR-FORS when employed to the examination of oil paintings were evaluated. It has been proved that the detection limits for this kind of set-up are especially high, although the major areas investigated permit to achieve better reproducibility and more representative information with respect to micro-FTIR. The physical feature/roughness of the analysed surface is a critical factor that may cause distortions in the spectra and be responsible for a decreased signal-to-noise ratio. It was achieved the creation of pigment mapping of oil paintings by means of midIR-FORS and multivariate methods. In a comprehensive study, the optimal data pre-processing methods as well as a protocol for the application of PCA and PLS-DA for FORS spectra modelling have been proposed. Furthermore, these methods were successfully applied to investigate and prove the influence of the surface roughness on the variability of the FORS spectra. Chapter 3 is focused on the assessment of the palette that was used by Pablo Picasso during the first years of his artistic career. The non-destructive punctual analysis techniques allowed achieving mappings of the elements/compounds detected across the entire surface of six portraits and it was possible to obtain a wide information about all the different regions of the artworks. In this study, it has been confirmed that an important limitation of this kind of techniques is the lack of information about the in depth composition and materials distribution, which has been partially overcome with the simultaneous and accurate evaluation of all available data complemented with NIR reflectography and XR radiography. In Chapter 4 the establishment of a procedure for faded silver image recovery in old photographs using XRF spectroscopy is proposed. The optimization of the method for sulphur detection in a first step, and the possibility to investigate two emblematic cases of silver images with this method allowed the demonstration of a relation between sulphur and silver, which is a key to the identification of high density areas that have lost the silver component over time. Chapter 5 present the study of the optimization and application of an analytical method for the characterization of ancient bronze objects. The unique opportunity to follow the analysis of the Donatello’s San Lorenzo Pulpit from the sampling to the ICP determinations allowed the investigation of all the possible sources of data variability. Thus, it was possible to compare the different parts of the structure and establish relations between the compositions of different samples that will be used by the conservator to complement the stylistic and historic study of the artwork. / El objetivo principal de la tesis es la evaluación de técnicas micro- y no destructivas para la caracterización material de obras de Patrimonio. Pinturas al óleo, fotografías antiguas y un objeto metálicos de gran formato se analizaron como representantes de tres importantes categorías artísticas. En el Capítulo 1 se presenta una introducción sobre los aspectos materiales y estructurales de las obras investigadas. El Capítulo 2 está dedicado a la determinación del límite de detección y reproducibilidad de Microscopia Electrónica de Rastreo (Scanning electron microscopy with Energy Dispersive X-Ray analysis, SEM-EDS), Espectroscopia de infrarrojo en transmisión (Fourier transform infrared spectroscopy, micro- FTIR) y en modalidad remota una sonda de fibras ópticas (mid infrared fiberoptics reflectance spectroscopy midIR-FORS). En el caso específico del midIR-FORS se ha demostrado la capacidad de métodos multivariantes para la modelización de los espectros obtenidos con tal técnica, y la creación de mapas de distribución de pigmentos a lo largo de la superficie de pinturas al óleo. El Capítulo 3 se centra en el estudio de la paleta usada por Pablo Ruiz Picasso durante sus primeros años de producción artística mediante el análisis no-destructivo de seis retratos conservados en el Museo Picasso de Barcelona. En el Capítulo 4 se propone un método analítico optimizado para la detección de azufre en fotografías antiguas (silver print image) mediante Fluorescencia de Rayos-X (X-Ray Fluorescence XRF) y un procedimiento para la recuperación de imágenes que manifiesten fenómenos de descoloración. Finalmente en el Capítulo 5 se presenta el estudio de la optimización de un procedimiento analítico para el análisis de muestras metálicas y aplicación a muestras reales extraídas del Pulpito de San Lorenzo de Florencia. La investigación de estas tres categorías artísticas ha demostrado la importancia de optimizar procedimientos de análisis específicos para incrementar el conocimiento de las obras teniendo en cuenta su heterogeneidad, características físico-químicas y respetando su integridad física.

Los metilsiloxanos volátiles (VMS) constituyen un nuevo grupo de contaminantes cuya presencia en el medio ambiente ha suscitado en los últimos años una especial atención debido a que presentan una elevada persistencia, capacidad de bioacumulacion y provocan efectos tóxicos y potencialmente cancerígenos en los organismos vivos. Hasta el momento, los datos disponibles sobre su presencia y distribución en el medio ambiente son muy limitados y, por tanto, existe un gran interés por conocer el impacto real que provocan estos contaminantes. Además, el análisis de estos compuestos en muestras ambientales conlleva serias dificultades debido a su elevada volatilidad y a la contribución como contaminación de fondo a las muestras. En base a esta problemática, el objetivo de esta tesis es el desarrollo de nuevos métodos de análisis para la determinación de VMS mediante la cromatografía de gases acoplada a espectrometría de masas (GC-MS), y estudiar su presencia y distribución en muestras ambientales de diferente naturaleza. Debido a que los VMS son compuestos de elevada volatilidad, en esta tesis se han desarrollado métodos de análisis empleando la técnica HS-SPME para el análisis de VMS en aguas fluviales y mejillones. También se utilizaron discos de extracción en fase sólida (SPE disk) de C18 de pequeño formato (5,5mg/1ml) para el anàlisis de la fase disuelta de aguas residuales. Para el análisis de la fase particulada del agua residual, además de suelos y lodos se utilizó la extracción con n-hexano y purificación del extracto con cartucho de SPE de sílice (100mg/1ml). En esta tesis también se ha abordado el análisis de VMS en aire mediante el uso de cartuchos de isolute ENVI+ para la retención de los analitos. Se aplicó la inyección de grandes volúmenes con la técnica Concurrent solvent recondensation-large volume injection (CSR-LVI), para incrementar sensibilidad de la determinación en todos los métodos establecidos. Los métodos desarrollados fueron aplicados al análisis de diferentes tipos de muestras, como suelos urbanos, lodos de depuradoras, aguas residuales sin tratar y tratadas, aire de exterior e interior y mejillones. En todas las muestras, las concentraciones encontradas de VMS mostraron un elevado predominio de los VMS cíclicos respecto a los lineales, siendo el decametilciclopentasiloxano (D5) el compuesto mayoritario. En general, las matrices más contaminadas con VMS fueron las aguas residuales y lodos de depuradoras, mientras que los niveles más bajos se encontraron en agua fluvial y suelos urbanos. El estudio de VMS en mejillones como bioindicadores de contaminación ha permitido detectar la presencia de estos compuestos en aguas de la costa catalana y determinar las zonas que presentan un mayor grado de contaminación. / Volatile methylsiloxanes (VMS) constitutes a new group of pollutants that has attracted special attention in recent years, because of their high persistence, bioaccumulation capacity, toxicity and potentially carcinogenic effects in living organisms. So far, data available about their presence and distribution in the environment are very scarce and therefore, studying the real impact caused by these contaminants is very interesting. On the other hand, the analysis of these compounds in environmental samples is very difficult due to their high volatility and their presence as background contaminants in the samples. Based on these facts, the aim of this work was the development of new analytical methods for the determination of VMS by gas chromatography coupled to mass spectrometry (GC-MS), and studying their presence and distribution in different types of environmental samples. Due to their high volatility, the analysis of VMS in river waters and mussels was carried out applying the HS-SPME technique. For the analysis of the dissolved phase of wastewaters, C18 solid phase extraction disks cartridges in small format (5.5 mg / 1 ml) were used. For analysis of the particulate phase of the wastewaters, soils and sludge samples, extraction with n-hexane followed by purification of the extract with silica SPE cartridge (100 mg / 1 ml) was used. The analysis of VMS in ambient air was carried out using isolute ENVI + cartridges for the sampling. Concurrent solvent recondensation-large volume injection (CSR-LVI) technique was used to increase sensitivity of the determination. The developed methods were applied to the analysis of different types of samples, such as urban soil, sewage sludge, wastewaters, indoor and outdoor air and mussels. In all the samples, a high prevalence of cyclic VMS were found with decamethylcyclopentasiloxane (D5) as the major component. In general, matrices with the higher pollution levels were wastewaters and sewage sludges, while the lowest levels were found in river waters and urban soils. The use of mussels as bioindicators of pollution allowed the detection of methylsiloxanes in the Catalan coast seawater identifying the areas with higher pollution.

This thesis mainly focuses on the use of high resolution mass spectrometry (HRMS) and accurate mass (AM) measurements for the characterization of dissolved organic matter (DOM) in natural and affected environments. HRMS and AM measurements have been used for the characterization and determination of organic compounds in the environment. The first part of the thesis starts with a review of HRMS terminology, followed by the discussion of some parameters influencing AM measurements and the procedure for the identification of organic compounds when using HRMS. A description of the main mass analyzers capable of acquiring high resolution (HR) mass data and some environmental applications are also presented and discussed. Additionally, to evaluate the capabilities of new mass spectrometers a comparison was carried out. Different mass analyzers were tested during a single day of work for the analysis of small molecules in negative electrospray (ESI) mode. This study was necessary in terms of a timely update on the topic, as other comparative studies had been carried out some years ago. Furthermore, the present study focuses on a wider mass range (not only a single m/z) and the negative ESI was tested as there were almost no data on AM measurements in this mode. Moreover, the analysis of DOM is usually preferentially acquired in negative mode. Some of the main features were compared: resolution, exact mass determination, sensitivity, simplicity and calibration protocol. Due to the selectivity and specificity of HRMS, it is one of the techniques that has given more information about DOM at molecular level. Description of the methodology applied to DOM characterization is found in the second part of the thesis. The isolation of DOM from different water bodies and the use of different mass analyzers have been optimized, in order to present some alternatives to the methods already used in the literature. Moreover, structural information about marine DOM has been obtained based on a method using HR tandem mass spectrometry. DOM has a very important role in many environmental processes as it is present in all natural waters. DOM is not toxic by definition, however the presence of DOM can influence the solubility and fate of anthropogenic pollutants in the aquatic media. For instance, DOM can significantly affect the drinking water quality in terms of taste, color, odor, transportation of organic pollutants and water treatment process. DOM has been reported as disturbing the good performance of the water treatments and it is said to be a precursor of disinfection by products (DBPs) formation. For these reasons, knowledge of DOM is of importance in drinking water treatment processes. The last part of the thesis is focused on the use of the methodology described above for the characterization of DOM along different water treatment plants. The study mainly focuses on the changes of DOM through advanced treatments based on membrane technology: ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO). Changes regarding the nature of DOM have been observed when the water is treated through the RO and NF membranes, whereas no effect of UF on DOM was detected. Moreover, a method was developed to characterize the DOM adsorbed on two dissimilar NF membranes. There is no information at molecular level about DOM causing fouling to the membranes and this study brings new insights on this field. / L'objectiu de la tesis és la utilització de l'espectrometria de masses d'alta resolució i la mesura de massa exacta per a la caracterització de la matèria orgànica dissolta en masses d'aigua naturals i tractades. L'espectrometria de masses s'ha utilitzat extensament per a la caracterització i determinació de compostos orgànics en el medi ambient. En la primera part de la tesis s'introdueixen els conceptes bàsics de l'espectrometria de masses d'alta resolució i es posen de manifest estratègies per a identificar compostos orgànics en mostres complexes. A més, es mostren exemples desenvolupats al llarg de la tesis per il•lustrar les principals avantatges de l'espectrometria de masses d'alta resolució en front de l'espectrometria de masses en tàndem. Els analitzadors de masses capaços de dur a terme mesures de massa exacta s'han avaluat per identificar quins paràmetres (resolució, intensitat de senyal, protocol de calibratge) afecten més la mesura de massa i per tant, la posterior determinació de la fórmula elemental del compost en qüestió. L'espectrometria de masses d'alta resolució ha demostrat ser la tècnica que ha aportat més informació a nivell molecular de la matèria orgànica dissolta. En aquesta tesis s'ha utilitzat principalment aquesta tècnica per obtenir informació molecular i estructural de la matèria orgànica dissolta al llarg de diferents plantes de tractament. La descripció de la metodologia analítica utilitzada (mètodes d'extracció, anàlisis instrumental, anàlisi de dades) es descriu a la segona part d'aquesta tesis. S'ha comparat la metodologia més utilitzada i descrita a la bibliografia amb noves alternatives presentades a la present memòria. S'han pogut descriure els canvis a nivell molecular de la matèria orgànica en diferents tractaments de ultrafiltració, osmosis inversa i membranes de nanofiltració, instal•lades en diferents plantes pilot. A més s'ha desenvolupat un mètode basat en l'espectrometria de masses d'alta resolució, per caracteritzar la matèria orgànica adherida a les membranes, per obtenir informació de l'embrutiment de les membranes o fouling que disminueixen el rendiment dels tractament de membrana.