Thèses sur le sujet « Ultratrail »

Les anti-inflammatoires non stéroidiens (AINS) sont l’un des médicaments les plus utilisés dans le monde, accessibles sur ordonnances ou en vente libre. Plusieurs articles ont fait état d’une forte consommation d’AINS par des coureurs pendant les ultratrails. Plusieurs études montrent qu’environ 50% des coureurs utillisent des AINS sans ordonnance médicale, sans forcément connaître leurs effets indésirables et leur toxicité. A ce jour, seulement des données basées sur des questionnaires ont été rapportées sur la prévalence des AINS chez les ultratrailers. Or, en raison de la méconnaissance des coureurs concernant les AINS, l’utilisation du questionnaire peut entraîner des résultats faux positifs ou faux négatifs. Dans cette étude, nous avons étudié la prévalence des AINS chez les utratrailers via des prélèvements de salive et sang capillaire. Des protocoles de préparation d’échantillon et une méthode LC-MS/HRMS ont été développés puis validés pour 19 AINS dans la salive et pour 18 AINS dans le sang capillaire. La méthode a été appliquée avec succès sur des échantillons collectés auprès de participants de l’Ultratrail du Mont Blanc® (UTMB®) 2021. Les résultats ont montré une prévalence des AINS supérieure dans les prélèvements de sang capillaire (46,6%) que dans les prélèvements salivaires (18,5%) ainsi qu’à partir des données du questionnaire (13,8%). En conclusion, ce travail est le premier rapportant l’identification et la quantification d’autant d’AINS dans la salive et le sang capillaire. De plus, l’étude menée lors de l’UTMB® 2021 a montré que la recherche d’AINS dans le sang capillaire est le moyen le plus pertinent pour étudier la prévalence dans l’ultratrail
Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most used drugs worldwide accessible through medical prescription or over-the-counter (OTC). Several published articles have reported a high consumption of NSAIDs by runners during ultratrail. Pain relief and prevention are the main reasons for these drugs consumption by runners. Several studies reported that around 50% runners used NSAIDs without medical prescription, these data show that half of runner may have low information or even lack of information about NSAIDs adverse effects. Up to date, only questionnaire-based data reported about NSAIDs prevalence by the runners. Therefore, using questionnaire may not provide the right information and leads to false positive or false negative results. In this study, we used oral fluid (OF) and dried blood spots (DBS), as biological samples for the study of NSAIDs consumption prevalence by the runners. Sample preparation workflows and a LC-MS/HRMS analytical method were developed and validated according to European Medicines Agency guideline for 19 and 18 different NSAIDs in OF and DBS, respectively. The method was successfully applied on OF and DBS samples collected from Ultramarathon du Mont Blanc® 2021. Results showed a higher prevalence of NSAIDs using DBS (46.6%) than OF (18.5%) and questionnaire (13.8%). To conclude, this work is the first one that reported a LC-MS/HRMS method for identification and quantification of as many NSAIDs in oral fluid and dried blood spots. Moreover, the prospective study conducted on UTMB® 2021 showed that the analysis of drugs directly in DBS is the most relevant tool to determine the prevalence in ultratrail events

Detection of ultratrace levels of metallic ion impurities in hydrofluoric acid solutions and alkaline hydrogen peroxide solution was demonstrated using a silicon-based sensing electrode. The sensor's operation principle is based on direct measurements of the silicon open-circuit potential shift generated by the interaction between metallic ions and the silicon-based sensing surface. The new sensor can have practical applications in the on-line monitoring of microelectronic chemical processing. The detection of Ag+ content in KODAK waste water was carried out successfully by this novel sensor. Trace levels of organic impurities in the hydrofluoric acid solutions and in the cleanroom air were characterized by multiple internal reflection infrared spectroscopy (MIRIS) using an organics probe prepared directly from a regular silicon wafer.

Presented in this thesis are two methods that are coupled to the instrumentation for the recovery and analysis of ultra-trace illicit drug residues. The electrostatic dust lifting process is coupled with nanomanipulation-nanospray ionization to retrieve drug particles off of hard surfaces for analysis. For the second method, drug residues from fingerprint impressions are extracted followed by analysis. The methodology of these hyphenated techniques toward forensic science applications is applied as to explore limits of detection, sensitivity, and selectivity of analytes as well as immediacy and efficiency of analysis. The application of nanomanipulation-coupled to nanospray ionization-mass spectrometry toward forensic science based applications is considered as future improvements to trace and ultra-trace analysis.

Au vu de l'importance des propriétés du sélénium, de nombreux travaux ont été menés afin de développer des méthodes d'analyse de spéciation de cet élément. Le couplage entre la chromatographie liquide haute performance et le spectromètre de masse à couplage inductif est le plus utilisé. L'objectif des travaux réalisés dans le cadre de cette thèse a été d'atteindre l'analyse de spéciation du sélénium au niveau ultratrace, incluant à la fois des composés organiques et inorganiques. Pour cela, nous avons utilisé les dernières générations d'ICPMS quadripolaires équipés d'un dispositif de collision/réaction qui permet de supprimer les interférences polyatomiques sur les isotopes majoritaires du sélénium. L'optimisation des conditions d'utilisation de ce dispositif ainsi que l'amélioration des techniques en amont de la détection ont été successivement réalisées. Les techniques développées ont été validées puis appliquées à des échantillons d'eaux ainsi qu'à des échantillons biologiques. Ces méthodes permettent l'analyse de spéciation du sélénium au niveau du ng(Se). L-1 dans des échantillons réels
Due to the important properties of selenium, numerous works have been undertaken to realize the speciation analysis of this element. The coupling of an HPLC with a mass spectrometer is commonly used. This report presents the improvements realized on the existing methods to simultaneously analyse inorganic and organic species at the ultratrace level. We have used the last generation of quadrupole ICPMS equipped with collision/reaction cell to remove argon based polyatomic intereferences on major selenium isotopes. The optimization of this device as well as improvement of analytical steps before detection have been carefully realised. The developed techniques have been validated and applied to different water and biological samples at the ng(Se). L-1 level

Oceanographers use surface aluminium concentrations in open-ocean seawater as a tracer to fingerprint the location and magnitude of atmospheric dust deposition. It has become increasingly important to understand the role that such deposition plays in supplying trace elements to surface waters and consequently the effects such episodic supply has on moderating biological processes. For the purpose of real time analysis, quantification must be carried out by a system capable of being deployed shipboard. The most commonly employed technique for this purpose is flow injection analysis (FIA). This project aimed to develop a method for the onboard quantification of aluminium in seawater, specifically for the analysis of Antarctic surface waters. Initially, the project focussed on the establishment and optimisation of a FIA system incorporating fluorescent detection ·of the aluminium-lumogallion complex. Significant variables affecting the lumogallion chemistry; including, reaction pH, lumogallion concentration and reaction time were optimised for this specific FIA system. Since aluminium concentrations in Antarctic seawater are expected to be in the minomolar to subnanomolar range, investigation into the addition of an 8-hydroxyquinoline column to the manifold, for preconcentration purposes, was carried out. Although initial work involving quantification of aluminium in seawater samples appeared promising, complications .with the robustness of this technique forced an alternative method to be sought. High performance chelation ion chromatography (HPCIC) was considered a suitable alternative for development as a technique for the purpose of shipboard quantification of aluminium in seawater. The HPCIC system developed, involved the novel use of iminodiacetic acid functionalised silica for the separation of aluminium. Separation conditions, such as eluent composition and column temperature were optimised. Both photometric and fluorometric detection systems were developed, employing post column reaction (PCR) with a variety of reagents. Of those tested for photometric detection, Eriochrome® Cyanine R, which was used for the first time for PCR determination of aluminium in a flow system, was found to be the most sensitive. A limit of detection of 100 nM for a 100 μL injection volume was achieved for this particular system. For the HPCIC system with fluorescence detection, lumogallion was the reagent of choice given its reported high sensitivity. Variables such as buffer type and pH, as well as temperature and lumogallion concentration were optimised. A limit of detection of 0.39 nM for a 500 μL injection volume was obtained, with the performance of the system with a variety of other injection volumes also examined. Finally, this study presents a discussion on the applicability of the newly developed HPCIC system to the quantification of aluminium in real samples. This work involves the analysis of paper mill process water and seawater from the Ross Sea, Antarctica. Particular attention is given to the topic of aluminium speciation with sample acidification. Conclusions and suggested future direction of studies in this area conclude this project.