Les usines de l’amont du cycle du combustible nucléaire, génèrent des effluents industriels faiblement chargés en uranium. La récupération de l’uranium de ces effluents vise à les décatégoriser (diminution de la radioactivité) et à valoriser l’uranium recyclé. L’acide sulfurique est majoritairement utilisé dans l’amont du cycle du combustible. Dans ces conditions, l’uranium est sous forme de complexes de sulfates d’uranyles qu’il convient d’extraire sélectivement vis-à-vis d’ions compétiteurs comme le Mo ou le Fe. Plusieurs procédés peuvent être envisagés : précipitation, extraction liquide-liquide et extraction sur supports solides. Cette dernière technique est particulièrement attractive pour des solutions faiblement chargées en uranium : elle est éco-responsable (évite la manipulation de solvants organiques), les procédés sont compacts et nécessitent peu de manipulations (i.e. extraction sur lit fixe). Parmi les supports solides à forts potentiels, les silices mésoporeuses occupent une place de choix de par leur grande surface spécifique, leur facilité de synthèse et leur facilité de caractérisation.Cette thèse se propose d’évaluer l’extraction d’uranium en milieu sulfurique par l’utilisation de silices hybrides mésoporeuses au sein desquelles sont greffées des molécules extractantes sélectives. Dans un premier temps, différentes molécules extractantes ont été sélectionnées, synthétisées puis greffées sur une silice commerciale afin d’évaluer les propriétés extractives de ces différentes familles d’extractant. Les N,N-carbamoylalkylphosphonates ont été identifiées comme étant des molécules intéressantes en terme de propriétés extractives. De plus, cette étude souligne la nécessité d’avoir un monoacide sur le groupement phosphonate et montre l’importance des chaines alkyles aussi bien sur le phosphonate que sur le groupement amide. A la suite de ce travail, l’impact du diamètre de pore des supports de silice sur la configuration de la partie organique greffée et sur les propriétés d’extraction de l’uranium a été mis en évidence. Une gamme de porosité (entre 3 et 20 nm) pour laquelle les matériaux hybrides sont homogènes et présentent une bonne efficacité d’extraction a été identifiée. Pour parfaire la compréhension des mécanismes d’extraction via les supports hybrides, une étude paramétrique (pH, force ionique, présence d’éléments compétiteurs) a été menée en parallèle d’analyses spectrométriques (EXAFS, FT-IR, Raman, DRX). Ces techniques ont permis de proposer un mécanisme d’extraction au sein du solide impliquant deux diamido-phosphonates par uranyle. Les résultats obtenus à l’échelle moléculaire sont en accord et confortent les propriétés macroscopiques observées lors de l’analyse paramétrique. / Nuclear industries are perpetually looking for technical, economic and environmental progresses. Important volumes of acidic waste are generated by nuclear plants of the front end. The extraction of uranium from these solutions is required to decontaminate effluents (decrease of the radioactivity) and value uranium (reincorporation in the cycle). Uranium leaching is mostly achieved using sulfuric acid leading to the production of aqueous effluents that contain a large grade of sulfate complexes. In such conditions, uranyl sulfate complexes constitute the predominant uranium species in solution and its extraction represents a real scientific and technological challenge. Commonly, precipitation, solvent extraction or solid phase extraction are used. The last one is particularly adapted for low grade solutions due to it weak environmental footprint (no solvent are handling) and the facility of the process involved (i.e. fixed bed column). Among the available solid-phase extraction candidates, hybrid mesoporous silicas get a crucial part. They develop a very high specific surface areas and a driven porosity which give them a high potential of extraction capacities.In this manuscript the tailoring and the evaluation of hybrid mesoporous silicas have been investigated. Firstly, the work focus on the organic part grafted by post-synthetic pathway, the N,N-dialkylcarbamoylphosphonate based molecules have been identified to get interesting extraction properties. This study emphasizes that acid groups are required and that alkyl substituents get a real importance in the extraction efficiency. On the second hand, the role of pore size has been investigated. The results obtained disclosed that pores size diameters directly impact the grafting ratio as well as the homogeneity of the material: (1) materials with a pore size below 3 nm are heterogeneously functionalized due to steric issues, (2) a homogeneous organic monolayer grafted onto the silica skeleton occurs when the pore size ranges from 3 nm to 20 nm and (3) functionalization of material having pore size above 30 nm results in an organic multilayer covalently linked to the surface. The organic self-organization drives the extraction efficiency, only monolayers lead to promising results. At the saturation state, two molecules are required to extract one uranyl ion. To describe the molecular scale of the uranyl complex onto the solid, the local structure has been investigated by a parametric study and spectroscopic techniques (IR, EXAFS and DRX). Results reveal that two diamido-phosphonates are involved in the uranyl extraction. By this work, it is shown how the molecular scale helps to understand the macroscopic phenomena.Finally, continuous extraction in a fixed bed column confirms the extractive properties obtained in batch mode experiments and points out the potential of such material to be reused several times without any damages.

L'analyse des lanthanides à l'état de trace dans les matrices environnementales requiert souvent une étape de purification et de préconcentration. L'extraction sur phase solide (SPE) est la technique la plus utilisée dans le domaine du traitement de l'échantillon. Cette thèse a consisté à développer des polymères à empreintes ioniques (IIP) pour l'extraction sélective des lanthanides (Ln3+). Tout d'abord, des IIP ont été préparés selon l'approche de piégeage en utilisant le 5,7-dichloroquinoline-8-ol, un ligand non vinylique. La perte de ce ligand, supposé piégé, durant les étapes d'élimination de l'ion empreinte et de sédimentation succédant à la polymérisation a été démontrée en HPLC-UV. Cette perte non répétable a entraîné un manque de répétabilité des profils SPE sur deux IIP préparés dans les mêmes conditions. Cela a permis de démontrer que cette approche de synthèse pour des IIP n'était pas adéquate. Ensuite, des IIP ont été synthétisés par immobilisation chimique en utilisant l'acide méthacrylique comme monomère vinylique. La répétabilité des étapes de synthèse et d'extraction a été démontrée. Une sélectivité pour l'ensemble des lanthanides a été obtenue et des applications avec des échantillons réels ont été faites avec succès. Enfin, des IIP obtenus par immobilisation chimique d'acide méthacrylique et de 4-vinylpyridine comme monomères ont été synthétisés avec comme ion empreinte soit un Ln3+ léger (Nd3+) soit un Ln3+ lourd (Er3+). Des sélectivités identiques de ces IIP pour l'ensemble des Ln3+ ont été obtenues dans les deux cas. Cependant, cette sélectivité a pu être modulée en changeant la nature et le pH de la solution de lavage utilisée dans le protocole SPE. / The analysis of the lanthanide ions present at trace level in complex environmental matrices requires often a purification and preconcentration step. The solid phase extraction (SPE) is the most used sample preparation technique. To improve the selectivity of this step, Ion Imprinted Polymers (IIPs) can be used as SPE solid supports. The aim of this work was the development of IIPs for the selective extraction of lanthanide ions from environmental samples. In a first part, IIPs were prepared according to the trapping approach using 5,7-dichloroquinoline-8-ol as non-vinylated ligand. For the first time, the loss of the trapped ligand during template ion removal and sedimentation steps was demonstrated by HPLC-UV. Moreover, this loss was not repeatable, which led to a lack of repeatability of the SPE profiles. It was then demonstrated that the trapping approach is not appropriate for the IIPs synthesis.In a second part, IIPs were synthesized by chemical immobilization of methacrylic acid as vinylated monomer. The repeatability of the synthesis and the SPE protocol were confirmed. A good selectivity of the IIPs for all the lanthanide ions was obtained. IIPs were successfully used to selectively extract lanthanide ions from tap and river water. Finally, IIPs were synthesized by chemical immobilization of methacrylic acid and 4-vinylpyridine as functional monomers and either a light (Nd3+) or a heavy (Er3+) lanthanide ion as template. Both kinds of IIPs led to a similar selectivity for all lanthanide ions. Nevertheless, this selectivity can be modified by changing the nature and the pH of the washing solution used in the SPE protocol.

Microfluidics miniaturizes many benchtop processes and provides advantages of low cost, reduced reagent usage, process integration, and faster analyses. Microfluidic devices have been fabricated from a wide variety of materials and methods for many applications. This dissertation describes four such examples, each employing different features and fabrication methods or materials in order to achieve their respective goals. In the first example of microfluidic applications in this dissertation, thermoplastics are hot embossed to form t-shaped channels for microchip electrophoresis. These devices are used to separate six preterm birth (PTB) biomarkers and establish a limit of detection for each. The next chapter describes 3D printed devices with reversed-phase monoliths for solid-phase extraction and on-chip fluorescent labeling of PTB biomarkers. I demonstrate the optimization of the monolith and selective retention of nine PTB biomarkers, the first microchip study to perform an analysis on this entire panel. The third project describes the iterative design and fabrication of glass/polydimethylsiloxane (PDMS) devices with gold and nickel electrodes for the self-assembly of DNA nanotubes for site-selective placement of nanowires. Simple flow channels and “patch electrode” devices were successfully used, and DNA seeding was achieved on gold electrodes. Finally, a 3D printed device for cancer drug screening was developed as a replacement for one previously fabricated in PDMS. Devices of increasing complexity were fabricated, and those tested found to give good control over fluid flow for multiple inlets and valves. Although the applications and methods of these projects are varied, the work in this dissertation demonstrates the potential of microfluidics in several fields, particularly for diagnostics, therapeutics, and nanoelectronics. Furthermore, it demonstrates the importance of applying appropriate tools to each problem to gain specific advantages. Each of the described devices has the potential for increased complexity and integration, which further emphasizes the advantages of miniaturized analyses and the potential for microfluidics for analytical testing in years to come.

Oil spills, especially in water have happened throughout the years. The consequences from this kind of incident have always been a threat to marine life and take a lot of money and time to clean up. The forensic investigations of oil usually focus on oil spill in water, however, this kind of investigation can be applied on more areas, such as in sexual offense cases and arson. The oil from the crime scene and the oil from the suspected source are analyzed and compared to each other to see if the compositions match. The aim of this thesis was to optimize the clean-up process of heavy fuel oil (HFO) using solid-phase extraction (SPE) according to the European Committee for standardization (CEN) 15522-2 method. HFOs are black oils, containing particles and soot which will decrease injector performance. Thus, a cleanup procedure is attractive when analyzing such samples. The three factors of optimization in this study were elution volumes, solvents, and SPE sorbents.The SPE method used in this study was to use the cartridges as a filter; therefore, the samples were both loaded and eluted with an organic solvent, in this case dichloromethane (DCM) or dichloromethane/heptane (DCM/Hp). The gas chromatography mass spectrometry (GC-MS) analysis method used is described in Annex B in the CEN 15522-2 method.Concluding, increasing the eluent volume did not indicate improvement on the extraction method. In terms of the solvents, both dichloromethane and dichloromethane/heptane showed similar results. The percentage weathering plots (PW-plots) showed that the SPE sorbents (dual layer florisil/Na2SO4, florisil and silica gel sorbents) worked similar. The overall conclusion from this thesis work was that further optimization must be made before implementing the method.

Over the last several decades, there have been a tremendous developments and greatinnovations in photocatalysis process along with the development of efficient nanosized catalysts for simple approach and economic viability. In this study, magnetic core@doubleshell nanomaterials were investigated and synthesized in lab with three-step innovative approach where Fe3O4 nanoparticles (NPs) were produced first to act as cores without using any surfactants. The magnetite/silica core–shell structure was then prepared by hydrolysis of tetraethoxysilane (TEOS) in the presence of core particles under alkaline conditions. And the outermost shell, the α-Fe2O3/TiO2 nanoparticles, were grown over magnetic core of Fe3O4@SiO2 using coprecipitation and calcination method. Furthermore, the Fe3O4@SiO2@α-Fe2O3/TiO2 NPs were then loaded on the reduced graphene oxide (r-GO) using hydrothermal method and are also mixed by kneading with the layered double hydroxides (LDH) of Mg2+ and Al3+. These nanoparticles were characterized with scanning electron microscope (SEM), transmission electron microscope (TEM), dynamic light scattering (DLS), and energy dispersive X-ray spectroscopy (EDS). Different model compounds like microcrystalline cellulose (90 μm), D-xylose, and sodium lignosulfonate representing cellulose, hemicellulose, and lignin, respectively, were converted to valuable chemicals with different NPs under visible light for different time periods. For example, valeric acid (VA) and vanillylmandelic acid (VMA) were produced when cellulose was used for the conversion with core-double shell NPS which were quantified using high performance liquid chromatography (HPLC). Similar approach was adopted for the conversion of brewers’ spent grain (BSG), a lignocellulosic biomass, without oxygen under visible light, which yielded ethanol as the main product along with other sugars and acids of very low concentrations. The magnetic property of the nanomaterials made it easy for recycle and reuse. From a sustainability point of view, this study will fill a large need in the biomass photocatalysis field by developing core-shell multi-functional photocatalysts for direct transformation of lignocellulose into valuable chemicals under low temperatures, atmospheric pressure, and visible light from the sun.

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

Polychlorinated biphenyls (PCBs) are a class of important organic pollutants which undergo very slow degradation and tend to persist for a long time in the environment. PCBs have various negative effects on living organisms, human health and the environment in general. A method for determining PCB levels in aqueous matrices was developed consisting of solid-phase extraction (SPE) and GC/MS determination. The average recoveries of PCB congeners from artificially spiked deionized water were around 85%. The PCB concentration of 3.3±0.1 μg·l-1 (a sum of selected congeners) was detected in contaminated groundwater originated from the area of a former asphalt concrete producing plant. The most abundant PCBs were trichlorinated congeners which together comprised about 80% of the total PCB content. The optimised SPE method was further applied together with accelerated solvent extraction (ASE) to assess the degradation potential of oyster mushroom (Pleurotus ostreatus) which shows high degradation efficiency of various organic pollutants including PCBs. P. ostreatus belongs to ligninolytic (white-rot) fungi, which is a very promising group of microorganisms frequently studied due to their bioremediation potential. P. ostreatus, strain KRYOS was able to remove 41±8% of the initial amount (50 μg) of the...

In forensic toxicology, opioids are frequently associated with drug abuse or drug-related death cases. An optimal method for use in the identification and quantification of opioids in a complex blood matrix is of paramount importance. Along with the ability to identify and quantitate opioids, this method should be accurate, sensitive, and selective. The application of sample pre-treatment and solid-phase extraction are common to purify and concentrate the target analytes before analyzing with liquid chromatography-tandem mass spectrometry. The purpose of this study was to compare the performance of two standard operating procedures, adopted by the Massachusetts State Police Crime Laboratory Toxicology and the Biomedical Forensic Sciences– Toxicology Laboratory at Boston University School of Medicine, for detecting opioids in blood. A total of eight drugs were analyzed: 6-monoacetylmorphine, codeine, fentanyl, hydrocodone, morphine, norhydrocodone, oxycodone, and oxymorphone. Comparison was performed using the parameters studied as part of method validation, including calibration model, bias, precision, carryover, interferences, ionization suppression/enhancement, and recovery. The results indicated that the method from Massachusetts State Police provided a better performance with between-run precision, interferences from matrix and other commonly encountered drugs, matrix effect at high concentration (250 ng/mL) and matrix recovery. Meanwhile, the method from Biomedical Forensic Sciences showed less bias, within-run precision, and matrix effect at low concentrations. Carryover and internal standard interference were comparable in both standard operating procedures. The calibration models were adjusted by altering the selection of regression model for improved quantification method performance. The volume of solvents, sample matrix, as well as time, were taken into consideration in accessing the overall performance of identification and quantitation. Both procedures were comparable yet the one from Massachusetts State Police was more beneficial in identifying the target analytes with greater sensitivity and selectivity and the one from Biomedical Forensic Sciences was more economical and efficient.

Introduction: Post-mortem whole blood samples differ greatly in quality, lipemia is one cause of concern in toxicological analyses. Around 4 % of all samples sent to RMV are given a notation of lipemic content. The aim of the thesis was to study the effects of lipemia on the quantification of 14 benzodiazepines and 5 similar sedative and antianxiety drugs as well as evaluate the pre-analytical process aiming to reduce the effects of lipemia.  Methods: Blood samples were simulated with bovine blood, analyte spiking, and lipid spiking with either the nutrition emulsion Intralipid or with a mixture of post-mortem lipids from authentic samples. The outset was the by RMV currently used LLE method followed by UPLC- MS/MS and the extraction method was altered and evaluated. Matrix effects were also studied.  Results: Lipemia were found to be a great interference when quantifying benzodiazepines. For most analytes, internal standard could compensate for the loss of analyte but there was a problem with analytes not having their own IS. The 7-amino-compounds were greatly affected by lipemia and propiomazine and dihydropropiomazine showed extreme losses. Equilibration of IS did not result in similar loss as analyte. Dilution of sample reduced losses caused by lipemic content. SPE resulted in extracts free from lipids and high yields but there were analyte losses similar to LLE. No matrix effects from the lipids were found. Samples spiked with Intralipid gave poorer analyte yields than those spiked with post-mortem lipids.  Conclusion: Dilution is the most successful method to reduce pre-analytical matrix effects as long as the concentration is not so low that it risks getting lower than the analytical limits when doing so. Not homogenising samples before sampling is giving incorrect results. SPE could, if optimised for the analyte retention and elution, remove lipids from samples and obtain accurate analyte concentrations. Pooling lipids from post-mortem samples is a possible method for simulating lipemic whole blood. Intralipid and the PM-mix gave the same indications, but to different extents. Further studies where the ability to mimic authentic lipids are needed for both Intralipid and PM-mix.

Improved analytical methods using novel cleanup techniques and inexpensive instrumentation for the determination of residue estrogens in municipal wastewater and swine lagoon wastewater have been developed. Presented approaches are less expensive, less time consuming, yet produce comparable detection limits and extraction efficiencies to existing methods. Chapter I provides an overview on environmental estrogens. Chapter II describes a novel method to quantify five estrogens including estriol, estrone, 17alpha-estradiol, 17beta-estradiol, and 17alpha-ethynylestradiol in influent and effluent municipal wastewater. The method includes sample preparation using solid-phase extraction followed by a “QuEChERS” cleanup, dansylation and LC/MS/MS detection. Hydrophilic-lipophilic balance solid phase extraction (SPE) was used for sample preconcentration and the extract was cleaned up using a dispersive SPE method using MgSO4, PSA and C-18. The resulting extract was then derivatized with dansyl chloride. Separation was achieved on a C-18 column and quantification was accomplished in the positive ion mode using multiple reaction monitoring. The method is capable of detecting below 1 ng/L. Chapter III describes improved approaches to quantify five estrogens and two conjugates, Estrone 3-glucuronide and beta-Estradiol 3-sulfate, in swine lagoon wastewater and storm water runoff. A considerable residue was collected when lagoon wastewater samples were centrifuged therefore both resulting residues and aqueous portions were analyzed separately. Analysis of the aqueous portions was carried out using a similar approach to the method described in Chapter II. However, a simple test-tube liquid-liquid extraction was used as an additional sample clean-up step. A modified QuEChERS method was utilized to efficiently extract the target analytes in the residue. Methods have 0.9 – 2 ng/L detection limits. Chapter IV describes an approach to quantify residue estrogens in municipal wastewater using a comprehensive two-dimensional gas chromatograph (GCxGC). This method requires no further cleanups after SPE and has detection limits ranging from 1.4 – 22.2 ng/L. All presented methods use relatively small initial sample volumes and produce negligible matrix interferences. The developed methods were validated by performing mini surveys on the estrogen levels in environmental aqueous matrices in north Mississippi.