Nesta tese foram desenvolvidos sensores amperométricos baseados em porfirinas supramoleculares e hidróxido de níquel nanoestruturado e estabilizado na fase alfa, bem como novos materiais baseados em hidróxidos mistos de níquel e cobalto nanoetruturados e estabilizados na fase alfa. Também, um analisador FIA amperométrico, foi desenvolvido em colaboração com o Laboratório de Instrumentação Analítica do IQ-USP, para a determinação e quantificação de SO2 livre em amostras reais, como vinhos, águas de coco e sucos de frutas. Os sensores amperométricos baseados em porfirinas supramoleculares foram empregados na determinação de SO2 livre, presente em sucos de frutas e águas de coco, utilizando um sistema FIA amperométrico. O sistema FIA amperométrico foi constituído de um injetor manual, uma cela amperométrica em fluxo integrada a uma unidade de difusão de gases e um fluxo de uma solução de ácido sulfúrico e de uma solução de eletrólito. Possíveis interferentes como ácido ascórbico, catecol, glicose e benzoato de sódio foram avaliados antes de iniciar as análises das amostras reais. Os resultados das análises foram comparados com o método oficial Monier-Williams. Os níveis de SO2 livre encontrados nas amostras estavam de acordo com o que é preconizado pela Legislação Brasileira. Os eletrodos de FTO, modificados com hidróxido de níquel estabilizado na fase alfa, foram utilizados como sensores amperométricos para a determinação de glicose, usando um sistema FIA amperométrico. Estes sensores apresentaram excelentes respostas lineares em concentrações inferiores a 100 µM. Ainda estes sensores têm apresentado uma sensibilidade específica muito elevada para a glicose, provavelmente associada com a sua natureza nanoestruturada, e consequêntemente sua área superficial aumentada. No entanto o eletrodo modificado apresentou uma tendência de mudar de fase, da fase meta-estável alfa para a fase termodinamicamente estável beta, com o aumento da concentração de glicose. Novos materiais baseados em hidróxidos mistos de níquel e cobalto estabilizados na fase alfa também foram desenvolvidos. A partir de técnicas como difratometria de raio-x e Microbalança Eletroquímica de Cristal de Quartzo (MECQ) foi possível determinar a fase polimórfica dos materiais. Técnicas como AFM e MEV demonstraram que estes materiais são formados por nanopartículas com tamanhos de 5 nm. Estes nanomateriais apresentaram uma maior quantidade de carga específica, em comparação com o hidróxido de níquel puro. E por último um analisador FIA amperométrico automatizado foi desenvolvido para a realização de análises de SO2 livre em amostras líquidas. Este analisador é composto por reservatórios de soluções, sistema de amostragem, sistema de propulsão das soluções, cela FIA amperométrica integrada a uma unidade de difusão de gases, um sensor amperométrico, além de placas controladoras, mini-potenciostato e um software para controlar o equipamento. Uma elevada reprodutibilidade foi alcançada para análises sequenciais de uma amostra, mas quando a amostra foi trocada a reprodutibilidade foi muito baixa, sendo necessário mais desenvolvimento do sistema FIA automatizado nesta área. / New nanomaterials based on mixed nickel and cobalt hydroxides stabilized in the alpha phase, as well as amperometric sensors based on supramolecular porphyrins and stabilized alpha nickel hydroxide were developed in this thesis. An amperometric FIA sulfite analyzer was also developed in colaboration with of Group of Analytical Instrumentation of IQ-USP, for determination of free SO2 present in liquid samples such as wine, coconut water and fruit juices. The amperometric FIA system is constituted by manual injector, amperometric FIA cell with integrated gas diffusion unit and amperometric sensor based on supramolecular porphyrins, whereas sulfuric acid and electrolyte were used as reactive and carrier solution. Some species such as ascorbic acid, cathecol, glucose and sodium benzoate were evaluated as possible interferents before starting the analyses of real samples. The results were compared with those obtained with the official Monier-Williams method. The concentrations of free SO2 found in fruit juices and coconut water were in accordance with Brazilian law. The amperometric FIA sensors for determination of glucose were based on FTO electrodes modified stabilized alpha nickel hydroxide, which presented excellent linear responses at concentrations below 100 µM. These sensors have shown a very high specific sensitivity for glucose probably associated with their nanostructured nature, and consequent enhanced surface area. Nevertheless, the electrode material was shown to have an increasing tendency to change from alpha to the beta phase as function of the glucose concentration. New materials based on mixed nickel and cobalt hydroxides, stabilized in the alpha phase was prepared and characterized by techniques such as X-ray diffraction, thermogravimetric analysis and Electrochemical Quartz Crystal Microbalance to determine their polymorphic phase. The nanostructured nature of the mixed nickel and cobalt hydroxide materials was confirmed by microscopy techniques such as AFM and SEM. These new materials showed a high specific charge, in fact higher than of nanostructured stabilized alpha nickel hydroxide. An amperometric FIA sulfite analyzer system for liquid samples consisting of solution reservoirs, a sampling system, a solution propulsion system, an amperometric FIA cell with integrated gas diffusion unit, an amperometric sensor based on supramolecular porphyrins, in addition to controller boards, a mini-potentiostat and control software, was developed and tested for determination of free SO2. High reproducibility was achieved for sequential analyses of a sample but the reproducibility after exchange of samples was relatively low, needing further developments in the sampling system.

No description available.

This dissertation describes electrochemical oxidation of Padan 95 SP on Boron-doped diamond (BDD) electrode mainly by •OH radicals (which was measured by indirect method, i.e: the formation of 2-Hydroxylterephthalic acid (2-HTA)), Electro-Fenton and the combination with adsorption technology for increasing total organic carbon (TOC) removal efficiency. In this study, the formation of 2-HTA on BDD electrode via the reaction between terephthalic acid (TA) and •OH as a method to quantify hydroxyl radical formation was investigated. The degradation of Cartap in Padan 95SP (95 % Cartap) on BDD was investigated. Operating parameters such as applied current density, types of electrolyte and initial concentration of Padan 95SP were varied in order to determine their effect on the degradation efficiency of Cartap. The concentration of Cartap was determined by UV-Vis spectroscopy according to 5,5-Dithiobis-(2-nitrobenzoic acid) (DTNB) procedure. High Performance Liquid Chromatography (HPLC) and Gas Chromatography/Mass Spectrometry (GC-MS) were used to characterize the commercial Padan 95SP and the formation of by-products. The optimal conditions for Cartap degradation by electrochemical process have been established: concentration of electrolyte: 0.05 M Na2SO4, initial concentration of Padan 95SP: 300 mg·L-1, pH = 3, current density: j = 20 mA·cm-2. At this condition, Cartap decreases to 41 %, TOC decay reaches 8 %. To increase TOC decay at higher Padan 95 SP concentration in aqueous solution, the combination technique of electrochemical process with other techniques was proposed, e.g.: Electro-Fenton technique, pre-oxidizing by NaOCl or the Electro-Adsorption combination. In the Electro-Fenton technique, we investigated the influence of factors such as the presence of NaOCl in pretreatment of process, affects of H2O2 concentration, Fe2+ dosage, co-catalysts metals ion and pH. The efficiency shows approximately 80 % of TOC removed at 700 mg·L-1 Padan 95 SP. The combination of electrochemical with adsorption method shows the efficient removals of TOC and Padan 95SP (95 % Cartap) based on reagents oxidation in electrochemical process and adsorption of granular activated carbon (GAC), respectively. The influence of factors such as supporting electrolytes, flow rate, bed height, recycling number as well as initial concentration were investigated in order to determine their effects on TOC removal. The efficiency of this combination shows approximately 75 % of TOC and more than 90 % of Cartap removed at 700 mg·L-1 Padan 95 SP. Fourier Transform Infrared (FT-IR) and (Brunauer–Emmett–Teller) BET surface analysis were applied to investigate GAC before and after usage. The results have shown that the application of electrochemical technique with other methods can be the potential option for treatment of wastewater containing Padan 95 SP. / Diese Dissertation befasst sich mit der Reduktion des gesamten organischen Kohlenstoffs (TOC) aus wässriger Lösung, die Padan 95 SP enthält. Als Methoden zur Minimierung von TOC wurden die elektrochemische Oxidation von Padan 95 SP auf Bor-dotierter Diamant (BDD) Elektroden durch •OH Radikale, Elektro-Fenton und die Kombination mit Adsorptionstechnologien verwendet. Die •OH Radikale wurden dabei durch indirekte Methoden, z. B. die Bildung von 2-HTA gemessen. Zur Quantifizierung der Hydroxylradikalbildung wurde in dieser Studie die Bildung von 2-Hydroxylterephthalsäure (2-HTA) an BDD-Elektroden über die Reaktion zwischen Terephthalsäure (TA) und •OH untersucht. Weiterhin befasst sich die Arbeit mit dem Abbau von Cartap in Padan 95SP (95% Cartap) auf BDD über die Reaktion zwischen Cartap und Hydroxylradikalen. Betriebsparameter wie die angewandte Stromdichte, die Elektrolytarten und die Anfangskonzentration von Padan 95SP wurden variiert, um ihre Wirkung auf die Abbaueffizienz von Cartap zu bestimmen. Die Konzentration von Cartap wurde mittels UV-Vis-Spektroskopie mit dem 5,5-Dithiobis-(2-Nitrobenzoesäure) (DTNB) Verfahren bestimmt. Hochleistungs-Flüssigkeitschromatographie (HPLC) und Gaschromatographie/Massenspektrometrie (GC-MS) wurden verwendet, um das kommerziell erhältliche Padan 95SP und die Bildung von Nebenprodukten beim Abbau von Cartap zu charakterisieren. Die optimalen Bedingungen für die Cartap-Degradation durch den elektrochemischen Prozess wurden festgelegt: Konzentration des Elektrolyten: 0.05 M Na2SO4, Padan 95SP Anfangskonzentration: 300 mg·L-1, pH = 3, Stromdichte: j = 20 mA·cm-2. Unter diesen Bedingungen sinkt Cartap auf 41% und der TOC erreicht 8 % des jeweiligen Ausgangswertes. Um den TOC-Zerfall bei höher Padan 95 SP Konzentration in Wasser zu erhöhen, wurde die Kombination des elektrochemischen Prozesses mit anderen Techniken vorgeschlagen, z.B.: Elektro-Fenton-Technik, Oxidation mit NaOCl, oder die Kombination des elektrochemischen Prozesses mit einem Adsorptionsprozess. Bei der Elektro-Fenton-Technik wurde der Einfluss von Faktoren wieder Anwesenheit von NaOCl in der Prozessvorbehandlung, Auswirkungen der H2O2-Konzentration, Fe2+-Dosierung, Metallionen als Cokatalysatoren und der pH-Wert der Lösung untersucht, um die Wirkung auf die Abbau-Effizienz für Cartap zu bestimmen. Es konnten mit dieser Methode rund 80 % TOC, ausgehend von 700 mg·L-1Padan 95SP, entfernt werden. Die Kombination des elektrochemischen Prozesses mit einer Adsorptionsmethode ermöglicht eine effiziente Entfernung von TOC und Padan 95SP (95% Cartap). Dies basiert auf der Oxidation und anschließender Adsorption auf granularer Aktivkohle (GAC). Der Einfluss von Faktoren wie Leitelektrolyten, Flussrate, Betthöhe, Recyclingzahl sowie die Anfangskonzentration von Padan 95 SP wurde untersucht, um deren Auswirkungen auf die TOC Entfernung zu bestimmen. Durch die Kombination konnten so 75% desTOC und mehr als 90% Cartap bei 700 mg·L-1Padan 95 SP entfernt werden. Fourier-Transformations-Infrarot (FT-IR) und BET-Oberflächenanalyse wurden angewendet, um GAC vor und nach der Verwendung zu untersuchen. Die Ergebnisse haben gezeigt, dass die Kombination des elektrochemischen Prozesses mit anderen Methoden eine potentielle Option für die Behandlung von Abwasser, das Padan 95 SP enthält, sein kann.

Within the last decades low-dimensional frustrated quantum spin systems have attracted great interest in the field of modern research. In these systems a competition of various magnetic interactions takes place, leading to an energetically degenerated magnetic ground state, and thus to the occurrence of exotic, unconventional physical properties at low temperatures. This thesis focuses on the quasi one-dimensional frustrated spin chain system linarite, PbCuSO4(OH)2. In this compound the basic building blocks are CuO4 plaquettes which are connected to each other along one crystallographic direction, analogue to a chain. The frustration in linarite is established due to the competition between the magnetic interactions. The nearest-neighbor magnetic spins are coupled ferromagnetically along the chain via a coupling constant J1, while the next-nearest neighbors are coupled antiferromagnetically via a coupling constant J2. For this configuration it is not possible to satisfy all magnetic couplings simultaneously, hence the system is magnetically frustrated. In this work, comprehensive thermodynamic and nuclear magnetic resonance (NMR) studies demonstrate that linarite is one of the richest and most fascinating compounds in the class of low-dimensional frustrated magnets. By means of susceptibility, magnetization, specific heat, magnetocaloric effect, magnetostriction, and thermal-expansion measurements a rich magnetic phase diagram could be mapped out below a temperature of 2.8 K. The phase diagram contains five different magnetic regions/phases for an external magnetic field pointing along the chain direction. Based on the thermodynamic studies it was possible to calculate the exchange integrals within the frustrated J1-J2 model and extensions of it by using various theoretical approaches. The magnetic microscopic nature of the different long-range magnetic phases present in linarite were investigated by NMR measurements and by collaborative neutron scattering experiments. The ground state (phase I) is identified as an incommensurate elliptical helical structure. Via a theoretical modelling the 1H-NMR spectrum of the ground state could be explained, revealing a rearrangement of the zero-field structure in an external magnetic field of 2.0 T used for the NMR studies. By further increasing the external field the system undergoes a complex spin flop transition in two steps (phase I - phase III - phase IV). In phase III a phase separation takes place where one part of the spins form a circular spiral structure while the remaining fraction form a simple antiferromagnetic structure. In phase IV the remaining circular spiral structure vanishes, so that all spins collectively form the antiferromagnetic collinear phase. The most peculiar physical properties studied in this thesis take place in region V at high fields, showing only tiny features in the thermodynamic properties. The magnetic spins in region V form a sine-wave modulated spin-density structure as identified via NMR and neutron investigations. It is discussed whether region V is related to a multipolar phase or if the spin-density wave structure could possibly coexist with such a phase.

In dieser Dissertation wird der Einfluss unterschiedlicher Sauerstoff-Koordinationsgeometrien um ein zentrales Kobaltatom evaluiert. Genauer werden Oxide, die tetraedrisch und oktaedrisch koordiniertes Kobalt enthalten, synthetisiert und charakterisiert. Zudem wird ihre Aktivität in Hinblick auf die Sauerstoffentwicklungsreaktion (OER) unter alkalischen Bedingungen untersucht. Die elektrochemischen Analysen zeigen dabei, dass Materialien, die Kobalt in tetraedrischer Sauerstoffkoordination enthalten, die besseren Katalysatorvorläufer für die OER sind. Weiterhin kann demonstriert werden, dass das Herauslösen von inaktiven Metallen aus einer Struktur die Aktivität erhöht. Darauf basierend wird das neue Material Zn0.35Co0.65O vorgeschlagen. Es kristallisiert in der Wurtzitstruktur und enthält nur tetraedrisch koordinierte Atome. In alkalischen Lösungen wandelt sich die Wurtzitstruktur über die Zwischenstufe Co(OH)2 zum gamma-Co(O)OH um, und nahezu alles Zink wird aus der Struktur herausgelöst. Dadurch wird ein Material mit einer großen elektrochemisch aktiven Oberfläche gewonnen, das unterkoordinierte CoO(6-x) Oktaeder als aktive Zentren für die OER enthält. Hierdurch wird eine herausragende katalytische Leistung erreicht. Um weitere Einblicke in die OER zu generieren, wird Diffuse Reflexions UV/Vis (DRUV) Spektroskopie verwendet. Es werden neuartige Durchflusszellendesigns vorgeschlagen, die es erlauben, DRUV Spektren während der Katalyse aufzunehmen, d.h. operando. Durch diesen spektroelektrochemischen Ansatz werden Veränderungen der Katalysatoren während der OER beobachtet. So kann die Phasenumwandlung von Zn0.35Co0.65O erfolgreich verfolgt werden. Ebenso kann gezeigt werden, dass CoAl2O4 und Co2SnO4 nur an ihrer Oberfläche katalytische Aktivität aufweisen. Durch den Vergleich mit ex situ Analysen werden eindeutige Struktur-Eigenschaftsbeziehungen vorgeschlagen und tiefere Einsichten in die katalytisch aktiven Strukturmotive erhalten. / In this PhD thesis, the influence of different coordination geometries of oxygen atoms around a central cobalt atom is evaluated. Specifically, oxides containing tetrahedral and octahedral coordinated cobalt are synthesized, characterized and their activity towards the OER under alkaline conditions is evaluated. The electrochemical analyses reveal, that materials containing cobalt in tetrahedral oxygen coordination are better precatalysts for the OER. Furthermore, it is demonstrated that leaching of inactive metals from a structure increases the activity as well. Based on the previous mentioned, the new material Zn0.35Co0.65O is proposed. It crystallizes in the wurtzite structure and contains solely tetrahedrally coordinated atoms. In alkaline solutions, it transforms from wurtzite structure via a hydroxide to gamma-Co(O)OH, and nearly all Zn is leached from the structure. By this, a material with a large electrochemically active surface area is generated, that contains under-coordinated CoO(6-x) octahedra as active centers for the OER. Thus, outstanding catalytic performance is achieved. To generate further insights into the OER, diffuse reflectance ultraviolet visible (DRUV) spectroscopy is facilitated. Novel flow-cell designs are proposed, that allow to record DRUV spectra of catalysts under working conditions, i.e. operando. By this spectroelectrochemical approach, changes the catalysts undergo during the OER are observed. The phase transitions of Zn0.35Co0.65O are successfully followed, and it can be further shown, that CoAl2O4 and Co2SnO4 are only active at their surface. By comparison to ex situ analyses, clear structure-activity correlations are proposed, and deeper insights in the catalytically active structural motifs are obtained.

Ce travail de thèse s'inscrit dans le cas d'un projet européen nommé " microfluiD ". Ce projet vise principalement la détection des polluants organiques par voie microfluidique (les micotoxines dans les aliments de bétail, les bactéries et les métaux lourds). Devant les dangers écologiques des ions Pb2+, Hg2+ et Cd2+ dans l'environnement, il est important de multiplier le nombre d'analyses dans les eaux du robinet. L'utilisation de la fluorescence et des microlasers organiques présente de nombreux avantages. Outre leur faible coût, leur sensibilité ainsi que leur sélectivité, il est possible de concevoir à partir de ces techniques des dispositifs transportables sur le terrain. Deux approches sont principalement développées : Une première est basée sur la fluorescence ; elle a consisté à synthétiser des ligands fluorescents de type DPPS-PEG et CalixDANS-3-OH pour la détection du mercure et du plomb. Les études de la complexation des ions Hg2+, Pb2+ ont d'abord été effectuées en solution. La complexation de Cd2+ en circuit microfluidique à partir du composé commercial Rhod-5N a aussi été étudiée. Des résultats très prometteurs ont été obtenus pour la détection de Hg2+ par DPPS-PEG. Nous avons aussi étudié la possibilité de détecter Pb2+ à partir du CalixDANS-3-OH greffé sur les parois du circuit microfluidique. Malgré une dégradation de la sonde, nous avons réussi à détecter une faible concentration de plomb. Une très bonne sélectivité vis-à-vis des cations interférents testés a été obtenue. La seconde approche est basée sur la détection par microlasers. Nous avons synthétisé deux copolymères blocs pour la détection du plomb et du mercure. Des problèmes de solubilité nous empêchant de fabriquer des microcavités organiques à partir de ces polymères, une deuxième stratégie consistant à greffer les ligands spécifiques de Pb2+ et de Hg2+ sur les microcavités laser PMMA a été développée. Cette dernière nous a permis d'apporter une preuve de principe pour de la détection du mercure en fonctionnalisant le mercaptopropyltriéthoxysilane à la surface du PMMA. Ce travail nous a aussi amené à synthétiser des colorants laser à base de Bodipy pour la fabrication des microcavités lasers par polymérisation à deux photons (2PP).

Lors de cette thèse, la dégradation atmosphérique de trois COV (composé organique volatil), l'acétone, le phénol et le catéchol, a été étudiée. Ces composés sont considérés comme des composés d'intérêt atmosphérique majeurs du fait de l'importance de leurs sources d'émissions primaires (biogéniques, échappements automobiles ...) ou secondaires (oxydation d'autres COV). Ce travail a été réalisé dans deux laboratoires en utilisant deux dispositifs expérimentaux complémentaires (PC2A- Université de Lille 1, Département Chimie - Environnement – Douai). Les dispositifs utilisés sont le tube à écoulement rapide couplé à la fluorescence induite par laser et la chambre de simulation atmosphérique couplée à la chromatographie en phase gazeuse associée à plusieurs détecteurs (FID, IRTF, SM). L'utilisation conjointe de ces deux dispositifs a permis de mettre en évidence le chemin réactionnel prépondérant de la réaction d'oxydation de l'acétone par le radical OH°. Les études en chambre de simulation atmosphérique des réactions du phénol et du catéchol initiées par les radicaux OH° ont permis de déterminer les constantes de vitesse et de proposer des mécanismes réactionnels aboutissant à la formation des produits observés. Il s'agit de la première étude mécanistique de la réaction catéchol + OH°. Les résultats obtenus ont permis d'évoquer les implications atmosphériques de ces composés (durée de vie et impact environnemental).

Afin d'assurer le confinement de déchets radioactifs en milieu géologique profond, il est envisagé d'utiliser des matériaux argileux de site et des bentonites. Leur stabilité en présence de fer métal, constituant des conteneurs de déchets, est étudiée. Ces études démontrent que la réactivité de tels matériaux est principalement portée par les smectites dioctaédriques et les kaolinites qu'ils contiennent. En revanche, la présence de sulfures inhibe la réaction Fe(0)-argiles. La nature du produit de réaction dépend de la quantité de fer métal disponible. A pH basique, par contact physique avec les agents oxydants de la smectite (H+, OH- et Fe3+), le Fe(0) est corrodé. Cette réaction est favorisée par les hétérogénéités des surfaces latérales de la smectite, qui altérée définit un micro-domaine à l'intérieur duquel nucléent des serpentines-Fe si l'apport en fer est suffisant. De telles néoformations entrainent une diminution des propriétés de confinement de la barrière argileuse.

Pesticides are among the most pervasive environmental contaminants and they are an important potential risk for human health. Agricultural workers are constantly exposed to pesticide spray, drift and residues in the soil and foliage. Many agricultural pesticides are readily absorbed by the body, through contact with the skin, the respiratory track, the eyes, and the gastrointestinal system. Multiple studies have reported a strong association between pesticide exposure and various health outcomes including cancer. Oxidative stress and DNA damage have been proposed as mechanisms linking pesticide exposure to health effects and neurological diseases. The focus of the present translational study is to examine the relationship between human exposure to the organophosphate pesticide azinphos methyl (AZM) and oxidative stress by measuring biomarkers of oxidative stress in biological fluids (i.e., urine, serum) and peripheral blood lymphocytes (PBLs) of agricultural workers. The findings from these field studies will be validated in vitro by examining cultures of human lymphocytes treated with AZM for similar biomarkers of oxidative stress. Since the collection of PBLs from study participants is highly invasive and not suitable for studies involving younger subjects, we also examined buccal cells for biomarkers of oxidative stress (i.e., DNA damage) as a more universal source of human tissue to assess oxidative stress in pesticide exposed individuals. We demonstrated in this study that AZM induces oxidative stress and causes DNA damage in human tissues. Agricultural workers who had been exposed to AZM showed elevated serum levels of lipid peroxides, increased urinary levels of 8-OH-dG, and lymphocytes from these individuals showed increased DNA damage and associated changes in oxidative DNA repair enzymes. Biomarkers of oxidative stress were also elevated in human lymphocytes treated with physiologically relevant concentrations of AZM. In cultures of human lymphocytes, AZM caused a concentration-dependent loss of viability and associated increases in ROS and a reduction in intracellular GSH. We also demonstrated that viable leukocytes from the oral cavity can be readily obtained from humans and these buccal cells can be used to assess DNA damage following exposure to occupational and environmental genotoxicants. We also noted that oral leukocytes are especially sensitive to cryopreservation with DMSO and thus, these cells must be cryoprotected with 5% DMSO to preserve the viability of these cells for subsequent biochemical studies. In summary, these in vivo and in vitro studies demonstrated that AZM induces oxidative stress in a dose-dependent matter and that oral lymphocytes are a good source of human tissue for assessing DNA damage and possibly other biochemical changes. The possible health implications of the variations in these biomarkers of oxidative stress and DNA damage are undetermined. Yet the findings from these studies have provided a strong foundation for determining the mechanism by which pesticide induce oxidative stress, to explore the putative relationship between pesticide-induced oxidative stress and disease (e.g. cancer, neurodegenerative disorders) and determine whether tissue damage in humans is brought about by direct or by indirect action of organophosphate pesticides. / Graduation date: 2010

Bakgrund: Det finns läkemedel som ger ökad risk för vitamin D-brist. En kartläggningsstudie av hur patientgrupper med olika riskläkemedel hanteras i Landstinget i Kalmar län har inte gjorts tidigare. En sådan studie är önskvärd, för att få en nulägesanalys och öka medvetenheten bland hälso-och sjukvårdspersonal om hur läkemedel påverkar D-vitaminstatus. Syfte: Syftet var att undersöka omfattningen av ordinerade riskläkemedel hos samtliga patienter, samt hos patientgruppen ≥75år och hur dessa handläggs avseende ordination av supplementering (samtidig behandling med läkemedel innehållande vitamin D3 / kalcium och vitamin D3,), provtagning och analysresultat avseende kalcidiol i serum. Metod: Riskläkemedel för vitamin D-brist identifierades. Inklusionskriterier för studien var patienter med de fördefinierade riskläkemedlen med ordinationer under 2012 och/eller 2013. Populationen som ingick i studien var patienter i Landstinget i Kalmar län. Data hämtades från patientdatasystemet Cambio Cosmic. Utifrån dessa data analyserades förekomst av supplementering, provtagning för S-25(OH)D kalcidiol och analyssvar. Materialet strukturerades efter respektive läkemedel avseende kön och ålder (≥75 år.) Resultat: 9118 individer ordinerades något av riskläkemedelen orlistat, sevelamer, kolestyramin, kolestipol, efavirenz, prednison, prednisolon, fenytoin, fenobarbital eller karbamazepin. 31% av patienterna som ordinerats riskläkemedel var ≥75 år. Totalt behandlades 22% med supplementationspreparat av de som ordinerats riskläkemedel. I åldersgruppen ≥75 år behandlades 43% med supplement. 61% av de supplementerade patienterna var ≥75 år. Totalt provtogs enbart 4,1% avseende kalcidiol av de som ordinerats riskläkemedel. Av dessa hade 37% av de provtagna en bristnivå av S-25(OH)D (≤50 nmol/L) vid första provtillfället. 57% av de som visade brist supplementerades. Endast 8,3% av de som hade en brist följdes upp med ytterligare en eller flera provtagningar. Av patienterna ≥75 år provtogs 4,1% av patienterna i åldersgruppen. Detta innebär att 31% av de som provtogs var ≥75år. 39% led brist. Av de patienter ≥75 år som hade led brist supplementerades 65% av individerna. Konklusion: Det finns förbättringsutrymme för implementering av kunskap kring riskläkemedel i Landstinget i Kalmar län. / Introduction: Some drugs increase the risk for vitamin D deficiency. To date, no survey has been performed in Kalmar County about how patients medicated with risk pharmaceuticals are handled. Such a survey would be desirable in order to increase knowledge among healthcare workers about how substances interfere with vitamin D status. Aim: The aim was to examine the extent to which risk pharmaceuticals are prescribed among all patients and among patients aged ≥75, and to investigate how these patients are treated with respect to supplementation (drugs containing vitamin D3 / Calcuim and vitamin D3), blood sampling and analysis of serum calcidiol levels. Method: Drugs interfering with vitamin D were identified. Inclusion criteria for the survey were patients that had been prescribed the pre-defined risk pharmaceuticals during 2012 and/ or 2013. The surveyed population was residents in Kalmar County. Data were collected from the patient database Cambio Cosmic. From these data analyzes were made about the occurrence of: supplementation, sampling of S-25(OH)D calcidiol and test results. The collected data were arranged by substance, gender and age (elderly aged ≥75). Results: 9118 patients were prescribed at least one of the risk pharmaceuticals; orlistat, sevelamer, cholestyramine, colestipol, efavirenz, prednisol, prednison, phenytoin, phenobarbital or carbamazepine. 31% of these were aged ≥75. Overall, 22% of the patients were prescribed supplements. Out of these, 61% were elderly. Among the patients that had been prescribed risk pharmaceuticals a minority, 4,1% of the patients were sampled for calcidiol. 37% of these had deficiency in S-25(OH)D (≤50 nmol/L). 8.3% of patients with a vitamin D deficiency were sampled more than once. Out of the patients with deficiency 57% were treated with supplements. Out of the elderly patients prescribed risk pharmaceuticals, 4.1% of the patients were tested for calcidiol. This means that 31% of the tested patients were aged ≥75 and 39% of these had a deficiency. Out of the elderly patients with deficiency, 65% were treated with supplements. Conclusion: In Kalmar County, much can be done in order to better implement the existing knowledge about drugs that increase the risk for vitamin D deficiency. / Betydelsen av bra D-vitaminstatus för äldres hälsa – Hur stor är förekomsten av D-vitaminbrist hos äldre i Kalmar län och hur påverkar läkemedel D-vitaminstatus