Dissertations / Theses on the topic 'Zn solid phase speciation'

Thesis (Ph. D.) -- University of Maryland, College Park, 2006.
Thesis research directed by: Marine-Estuarine-Environmental Sciences. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.

Monomethylmercury, MeHg, is formed under anoxic conditions in waters, sediments and soils and then bioaccumulated and biomagnified in aquatic food webs, negatively effecting both human and wildlife health. It is generally accepted that precipitation of mercury, Hg, and adsorption of Hg to e.g. organic matter and mineral surfaces are important processes limiting the reactivity of Hg mobilized in the environment by natural and anthropogenic activities. However, knowledge concerning the role of different solid and adsorbed chemical forms of Hg for MeHg formation, evasion and bioaccumulation is missing. Such information is vital for the understanding of environmental processes controlling MeHg formation and bioaccumulation, as well as for predicting how changes in e.g. loading rates of atmospheric Hg and the outcome of climate change scenarios and anthropogenic land use could alter Hg concentrations in biota. In this thesis, a novel experimental approach, using isotopically enriched solid and adsorbed phases of inorganic Hg, HgII, as tracers, was developed. Using this approach, we successfully determined rates of MeHg formation from solid and adsorbed Hg species in sediment slurries and in mesocosm systems under conditions closely resembling those in field. We conclude that the solid/adsorbed phase speciation of HgII is a major controlling factor for MeHg net formation rates. Microcosm experiments revealed that newly formed MeHg was a major contributor to the evasion of MeHg from the water‒sediment system, emphasizing the importance of MeHg formation rate, rather than MeHg concentration, in the sediment for this process. From mesocosm systems, we provide experimental evidence, as well as quantitate data, for that terrestrial and atmospheric sources of HgII and MeHg are more available for methylation and bioaccumulation processes than HgII and MeHg stored and formed in sediments. This suggests that the contribution from terrestrial and atmospheric sources to the accumulation of Hg in fish may have been underestimated. As a consequence, in regions where climate change is expected to further increase land runoff, terrestrial MeHg sources may have even higher negative effects on biota than previously thought. Data and concepts presented in this thesis lay the basis for unprecedented in-depth modeling of processes in the Hg biogeochemical cycle that will improve our understanding and the predicting power on how aquatic ecosystems may respond to environmental changes or differences in loading rates for atmospheric Hg.
Monometylkvicksilver, MeHg, bildas under anoxiska förhållanden i naturliga vatten, sediment och jordar och bioackumuleras och magnifieras därefter i den akvatiska näringskedjan med negativa effekter på djur och människor som följd. Det är generellt vedertaget att utfällning av Hg och adsorption av Hg till exempelvis organiskt material och mineralytor begränsar tillgängligheten för biogeokemiska reaktioner av Hg som mobiliserats i miljön via naturliga och antropogena processer. Kunskap om betydelsen av speciationen av Hg i fasta och adsorberade faser för bildning, avgång och bioackumulering av MeHg är dock bristfällig. Denna information är kritisk för att förstå vilka processer som kontrollerar bildning och bioackumulering av MeHg samt för att kunna prediktera hur olika ekosystem kan förväntas svara på exempelvis ändrad deposition av atmosfäriskt Hg eller hur klimatförändringar kan påverka koncentrationerna av Hg i fisk. I denna avhandling har en experimentell metod utvecklades, där isotopanrikade fasta och adsorberade kemiska former av oorganiska tvåvärt Hg, Hg II används som s.k. "tracers". Denna metod användes för att bestämma MeHg bildningshasigheter i homogeniserade sediment prover samt i mesokosmsystem där förhållandena efterliknar de som förväntas i naturliga ekosystem. Från dessa drar vi slutsatsen att speciationen av HgII i fast/adsorberad fas är en viktig kontrollerande faktor som begränsar nettobildningen av MeHg. Mikrokosmexperiment visade att i första hand nyligt bildad MeHg avgick till gasfas vilket understryker betydelsen av MeHg bildningshastighet, snarare än koncentration, i sedimentet för denna process. Från mesokosmexperimenten visar vi, med kvantitativa data, att terrestra och atmosfäriska källor av HgII och MeHg är mer tillgängliga för bildning och bioackumulering av MeHg än HgII och MeHg lagrat eller bildat i sedimenten. Orsaken till detta är framförallt skillnad i speciationen av Hg i fasta/adsorberade faser. Detta innebär att bidraget från MeHg från terrestra och atmosfäriska källor till koncentrationen av Hg i fisk kan ha underskattats, samt att de negativa effekterna på MeHg exponering i områden där exempelvis klimat-förändringar förväntas leda till ökad terrest avrinning kan bli mer allvarliga än vad som tidigare predikterats. Data som presenteras i denna avhandling möjliggör modellering av Hg’s biogeokemiska cykel på en ny detaljnivå samt möjliggör säkrare prediktioner av hur olika ekosystem kan förväntas svara mot miljöförändringar eller ändrad deposition av atmosfäriskt Hg.

Till Finansiärer skall också följande läggas till: Kempe stiftelsen (SMK-2942, SMK-2745, JCK-2413).

The waters and sediments of Lake Coeur d'Alene (LCDA) in northern Idaho have been contaminated by heavy metals because of decades of mining operations. Metal speciation is critical in assessing toxicity because it may vary considerably with pH and is dependent on other aqueous constituents. There has been little research on integrated investigations of the effects of heavy metal speciation on indigenous microbes from LCDA, especially large scale community analysis. The focus of this research in the LCDA system was to determine the effect of heavy metal speciation on toxicity, first in a defined single organism system, followed by in situ studies. Combined results of thermodynamic modeling, statistical analysis, and batch culture studies using Arthrobacter sp. JM018 suggest that the toxic species is not solely limited to the free ion, but also includes ZnHPO₄⁰(aq). Cellular uptake of ZnHPO₄⁰(aq) through the inorganic phosphate transporter (pit family), which requires a neutral metal phosphate complex for phosphate transport, may explain the observed toxicity. These findings show the important role of "minor" Zn species in organism toxicity and have wider implications since the pit inorganic phosphate transport system is widely distributed in bacteria, archaea, and eukaryotes. Using a multivariate statistical approach, correlations between the microbial community (via 16S rDNA microarray) in sediment cores and operationally defined heavy metal phases (via continuous sequential extractions) were explored. Candidate phyla NC10, OP8 and LD1PA were only present in metal contaminated cores and diversity doubled among Natronoanaerobium in metal contaminated cores which may suggest some increased fitness of these phyla in contaminated sediments. Correlations show decreases in diversity from presumed sulfate reducing lineages within most taxa from Desulfovibrionales and Bdellovibrionales and from metal reducing bacterial lineages Shewanellaceae, Geobacteraceae, and Rhodocyclaceae with increases in the ratio of more bioavailable Pb exchangeable/carbonate to less bioavailable Pb oxyhydroxide. This is the first time these techniques have been used in combination to describe a contaminated system.

Characterising the geochemistry and speciation of major contaminant radionuclides is crucial in order to understand their behaviour and migration in complex environmental systems. Organic complexing agents used in nuclear decontamination have been found to enhance migration of radionuclides at contaminated sites; however, the mechanisms of the interactions in complex environments are poorly understood. In this work, radionuclide speciation and sorption behaviour were investigated in order to identify interactions between four key radionuclides with different oxidation states (Cs(I) and Sr(II) as important fission products; Th(IV) and U(VI) as representative actinides), three anthropogenic organic complexing agents with different denticities (EDTA, NTA and picolinic acid as common co-contaminants), and natural sand (as simple environmental solid phase). A UV spectrophotometric and an IC method were developed to monitor the behaviour of EDTA, NTA and picolinic acid in the later experiments. The optimised methods were simple, applied widely-available instrumentation and achieved the necessary analytical figures of merit to allow a compound specific determination over variable background levels of DOC and in the presence of natural cations, anions and radionuclides. The effect of the ligands on the solubility of the radionuclides was studied using a natural sand matrix and pure silica for comparison of anions, cations and organic carbon. In the silica system, the presence of EDTA, NTA and, to a lesser extent, picolinic acid, showed a clear net effect of increasing Th and U solubility. Conversely, in the sand system, the sorption of Th and U was kinetically controlled and radionuclide complexation by the ligands enhanced the rate of sorption, by a mechanism identified as metal exchange with matrix metals. Experiments in which excess EDTA, NTA and picolinic acid (40 – 100 fold excess) were pre-equilibrated with Th and U prior to contact with the sand, to allow a greater degree of radionuclide complex formation, resulted in enhanced rates of sorption. This confirmed that the radionuclide complexes interacted with the sand surface more readily than uncomplexed Th or U. Overall this shows that Th and U mobility would be lowered in this natural sand by the presence of organic co-contaminants. In contrast, the complexation of Sr with the complexing agents was rapid and the effect of the ligands was observed as a net increase on Sr solubility (EDTA, picolinic acid) or sorption (NTA). As expected, Cs did not interact with the ligands, and showed rapid sorption kinetics. Finally, ESI-MS was used to study competitive interactions in the aqueous Th-Mn-ligand ternary system. Quantification presented a challenge, however, the careful approach taken to determine the signal correction allowed the competitive interactions between Mn and Th for EDTA to be studied semi-quantitatively. In an EDTA limited system, Th displaced Mn from the EDTA complex, even in the presence of a higher Mn concentration, which was consistent with the higher stability constant of the Th-EDTA complex.

Chromium can act either as an essential micronutrient or a chemical carcinogen, depending on its oxidation state. Of the two most stable chromium oxidation states, Cr(VI) is a known carcinogen, while Cr(III) is an essential element. Determination of total Cr cannot therefore be used to evaluate food safety of dairy products, as speciation is required for accurate assessment of potential toxicity. In this study, total Cr was determined by DRC-ICP-MS after mineralisation of freeze-dried milk samples. Chromabond NH2 ion-exchange columns were used to separate Cr(VI) from Cr(III). During the separation process, Cr(VI) was selectively adsorbed onto the Chromabond NH2 column. The retained Cr(VI) was subsequently eluted with two column volumes of 2 M HNO3 and diluted to a final volume of 10 mL. After separation, the Cr(VI) was quantified by DRC-ICP-MS, using O2 as the reactive gas, to alleviate polyatomic ion interference. An O2 gas flow rate of 0.85 ml/min and a high-pass rejection parameter q (Rpq) ¼ 0.5, provided the best compromise signal-to-noise ratio. The method was validated through determining the recovery in milk samples spiked with Cr(VI). The recoveries were quantitative and ranged from 96.4 to 99.2%. A whole milk powder reference material (NIST SRM 8435) was used to evaluate the accuracy of the total Cr quantification method. The observed value showed concordance with the certified value. The limits of detection (LOD) were 0.091 and 0.085 mg/L for total Cr and Cr(VI), respectively. These findings are important for the determination of maximum residue levels (MRLs) of Cr(VI) in dairy products.

The emission of trace metals (TMs) into boreal forest regions of the northern hemisphere is an important environmental issue due to their potential detrimental impacts on these sensitive ecosystems. One of the foremost factors controlling metal cycling is the chemistry of the overlying organic forest floor of the forest soil. In this thesis we examine the chemistry of forest floor horizons of podzolic soils. Our goal is to improve our ability to predict the partitioning of metals between the soil solid and solution phases.
We developed a standard protocol to produce solutions that resemble lysimeter solutions from podzolic soils using air-dried samples. We hypothesized that the stabilization point of the electrical conductivity (EC) of the soil solution is indicative of the point in which soluble salts and organic material precipitated during sampling and storage are removed from the soil particle surfaces. Solutions produced by leaching the soils, once the EC of wash solutions had stabilized, were comparable to lysimeter solutions from the area where samples were collected with respect to the concentrations of divalent cations, pH, EC and dissolved organic carbon (DOC). The applicability of this procedure to trace metal partitioning in forest floors was explored. Laboratory extractions produced partition coefficients (log Kd) similar to observed lysimeter solutions ranging from 3.4 to 3.9 for Cd, 3.4 to 3.9 for Cu, 3.4 to 4.1 for Ni, 4.1 to 5.2 for Pb and 3.2 to 3.5 for Zn. According to a semi-mechanistic regression model based on observed lysimeter concentrations, the metal concentrations in solution were appropriate relative to known factors that influence metal partitioning in soils: pH, the concentrations of total metals and DOC.
While chemical characteristics of soils have been consistently observed to play important roles in the partitioning and toxicity of metals we wished to place the importance of the chemical characteristics of soil on mobility and toxicity in context. We interpreted field data that had been collected from transects established with distance from two point source emitters in Rouyn PQ, and Sudbury ON. Canada find developed equations that predict dissolved metal concentrations from total metal concentrations, soil pH, soil organic matter (SOM), and DOC contents. We integrated these equations into a simple box model that calculates changes in the concentration of metals in the organic and upper mineral horizons and includes a loop for vegetative return of metals to the forest floor.

Orientadores: Marco Aurelio Zezzi Arruda, Fabio Augusto
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica
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Resumo: Este trabalho de Tese visa acoplar a fibra, empregada em microextração em fase sólida (SPME, do inglês solid phase microextraction), ao espectrômetro de absorção atômica com forno de grafite (GF AAS, do inglês graphite furnace atomic absorption spectrometer), visando reter espécies organometálicas volatilizadas nas etapas de secagem e pirólise do GF AAS. O elemento escolhido para avaliar o acoplamento SPME-GF AAS foi o Sn. Primeiramente, a concentração total de Sn foi determinada, utilizando a amostragem em suspensão como estratégia, uma vez que na avaliação da distribuição dos compostos organoestânicos por SPME-GF AAS, a concentração total de Sn seria efetuada a partir de uma suspensão. Para a otimização do método foram avaliados os seguintes parâmetros: solução de preparo da suspensão, e efeito da temperatura de pirólise e atomização. A mistura contendo HF 10 % (v/v) e HNO3 1 % (v/v) foi escolhida para preparar a suspensão, a composição Mg(NO3)2 + NH4H2PO4 apresentou resultados apropriados para ser utilizada como modificador químico convencional, e 1000 e 2200 °C foram as temperaturas ótimas para a pirólise e a atomização, respectivamente. Devido ao efeito de matriz, foi utilizada a técnica de adição de analito para a quantificação de Sn em suspensões de sedimento marinho e de rio, em que os limites de detecção e quantificação calculados foram de 1,5-2,6 e 4,5- 7,6 µg g, respectivamente. Para avaliar o acoplamento SPME-GF AAS, visando à retenção das espécies organoestânicas (butiltricloroestanho, dibutildicloroestanho e tributilcloroestanho) foi utilizada, primeiramente, uma suspensão de sedimento. A suspensão foi sonicada e, em seguida, uma alíquota foi injetada no forno de grafite do GF AAS juntamente com o reagente de derivação (tetraetilborato de sódio - NaBEt4). A programação do forno de grafite foi aplicada e a fibra de SPME foi introduzida no atomizador. Após a retenção das espécies de interesse na fibra, a mesma foi conduzida ao cromatógrafo a gás (CG) para a separação e detecção dos analitos. Os parâmetros instrumentais do CG foram previamente estudados, visando a melhor separação das espécies de interesse. Esses estudos foram realizados utilizando o modo de extração por headspace e SPME (HS-SPME, do inglês headspace-solid phase microextraction). Em relação aos estudos envolvendo suspensões de sedimento no acoplamento proposto SPME-GF AAS, alguns parâmetros foram avaliados frente à retenção das espécies de interesse; entre eles pode-se citar o tipo de fibra, a concentração do reagente de derivação e o pH da reação. Melhores resultados foram observados para a fibra PDMS/DVB, utilizando uma concentração de 0,2 % (m/v) de NaBEt4 para a etilação das espécies de interesse, sendo a reação realizada em pH 5,0. Entretanto, baixa eficiência de retenção (< 20 %) das espécies de interesse em suspensão de sedimento, foi obtida utilizando-se o acoplamento SPME-GF AAS, quando comparada à extração por HS-SPME. Dessa forma, foi realizada uma extração das espécies de interesse das amostras de sedimento, utilizando a energia ultrassônica, anteriormente à sua aplicação no acoplamento proposto SPME-GF AAS. Nesta etapa do trabalho, a temperatura do forno de grafite e o tempo de exposição da fibra de SPME no forno de grafite foram otimizados, visando à máxima eficiência de retenção das espécies de interesse no acoplamento SPME-GF AAS. Os melhores resultados foram observados para temperaturas do forno de grafite de 90 °C, com 986 s de tempo de exposição da fibra no atomizador. Por fim, foram realizados experimentos visando determinar a concentração total de Sn, e reter suas espécies organometálicas simultaneamente, na fibra de SPME, utilizando o acoplamento SPME-GF AAS.
Abstract: The goal of this Thesis was coupling the solid phase microextraction (SPME) to graphite furnace atomic absorption spectrometer (GF AAS) for extracting the organometallic species volatilized in the drying and pyrolysis steps of the GF AAS. For evaluating the SPME-GF AAS coupling, Sn was then chosen. Firstly, the total Sn concentration using the slurry sampling strategy was determined, once in the evaluation of the organotin compounds by SPME-GF AAS, the total Sn concentration would be obtained from a slurry solution. Some parameters were evaluated, such as the nature of the solution to prepare the slurry, and pyrolysis and atomization temperatures effects. The mixture of 10 % (v/v) HF plus 1 % (v/v) HNO3 was chosen to prepare the sediment slurries, the Mg(NO3)2 plus NH4H2PO4 was appropriated as conventional chemical modifier, and the values of 1000 and 2000 °C was used as pyrolysis and atomization temperatures, respectively. The analyte addition was used in the Sn determination in sediment (marine and river) samples by slurry sampling due to matrix effects. The detection and quantification limits were calculated as 1.5-2.6 and 4.5-7.6 µg g, respectively. For evaluating the SPME-GF AAS coupling in the extraction of organotin species (butyltrichloride, dibutyldichloride, and tributylchloride), a sediment slurry was firstly used. For this task, the slurry was sonicated and an aliquot of this solution plus the derivatization reagent (sodium tetraethylborate ¿ NaBEt4) were introducted consecutively into the graphite furnace of the GF AAS. Then, the graphite furnace program was applied, and the SPME fiber was exposed into the furnace. After the extraction of organotin species by SPME-GF AAS, the analytes were separated and detected by gas chromatography (GC). Before this procedure, instrumental parameters of the GC were studied. For this task, it was used the conventional extraction by HSSPME (headspace-solid phase microextraction). Related to studies of SPME-GF AAS coupling, employing slurry sampling, some parameters, such as fiber coating, derivatization reagent concentration, pH of the reaction, among others, were evaluated. Satisfactory results were obtained using the PDMS/DVB fiber in the presence of 0.2 % (m/v) NaBEt4 and pH 5.0. However, low extraction efficiency (< 20 %) was obtained, using the SPME-GF AAS coupling for organotin species extraction from sediment slurries, when comparing to HS-SPME extractions. Then, the extraction of organotin species from sediment samples, using the ultrasonic energy was carried out, before the sample introduction into the SPME-GF AAS coupling. In this step, the graphite furnace temperature and the fiber exposure time in the atomizer were optimized. The better results were noted when 90 °C as the graphite furnace temperature was used, and 986 s was attributed as the fiber exposure time into the atomizer. Additionally, the determination of total Sn concentration, and the extraction of organotin species in the SPME fiber, using the SPME-GF AAS coupling, was simultaneously carried out.
Doutorado
Quimica Analitica
Doutor em Ciências

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Este trabalho relata o desenvolvido de métodos analíticos que visa à determinação de algumas espécies tóxicas e potencialmente tóxicas de metais e metalóides em níveis ultra-traço em amostra de água naturais, utilizando uma técnica analítica menos sensível, como a espectrometria de absorção atômica em chama (FAAS). Essa técnica foi escolhida por ser relativamente simples e possuir baixo custo operacional. A técnica de extração em fase sólida (EFS), utilizando um novo material sorvente, foi utilizada para separar e pré-concentrar os analitos. Este estudo demonstra o procedimento de uma nova rota sintética via co-condensação visando à produção de uma sílica mesoporosa organofuncionalizada com o ligante 4-amino-3-hidrazino-5-mercapto-1,2,4-triazole e, sua utilização como sorvente para pré-concentração/análise de especiação de íons metálicos em amostras de água. O material produzido foi caracterizado por espectroscopia na região do infravermelho (FTIR), BET, ressonância magnética nuclear (RMN) de 29Si e 13C, dentre outras. As características adsortivas desse material foram estabelecidas em estudos de batelada, onde se estudou o efeito do pH, cinética de adsorção e capacidade máxima de adsorção. A otimização multivariada foi utilizada para obtenção das melhores condições químicas e de fluxo no sistema de pré-concentração, permitindo avaliar as interações principais e secundárias entre os fatores. Por meio da análise dos espectros obtidos por FTIR foi possível observar bandas de estiramento C–H, C–Cl e (NH2) oriundos da fração orgânica do material. A área superficial foi de 369,84 m2 g-1com diâmetro médio de poros em 7,1 nm, relacionados a materiais mesoporosos. Os resultados obtidos por RMN de 29Si comprovam a formação do material híbrido, sintetizado por co-condensação, e o RMN de 13C confirma o ancoramento do ligante na matriz. O pH que favorece a adsorção dos íons foi 5,0 para Cu(II) e 3,0 para Cd(II) e As(V). O modelo cinético de pseudo segunda ordem apresentou melhor ajuste aos dados experimentais, indicando adsorção química. Os dados de sorção desses íons metálicos mostraram bom ajuste ao modelo de Langmuir, com capacidade máxima de adsorção próxima aos valores obtidos experimentalmente, 0,057, 0,018 e 0,060 mmol g-1 para Cu(II), Cd(II) e As(V), respectivamente, indicando que a sorção ocorre em monocamada. Os parâmetros analíticos encontrados para o Cu(II) foram: fator de pré-concentração de 18,1; intervalo linear de 10,0 – 200,0 µg L-1 (R = 0,999) e LD de 1,45 µg L-1. Para o Cd(II): fator de pré-concentração de 15,8; intervalo linear de 2,0 – 100,0 µg L-1 (R = 0,999) e LD de 0,38 µg L-1. Para o As(V): fator de pré-concentração de 5,0; intervalo linear de 0,25 – 2,5 µg L-1 (R = 0,999) e LD de 0,039 µg L-1. A exatidão foi checada pelo método de adição e recuperação e/ou método comparativo com GFAAS ou ICP OES. As recuperações variaram de 97 – 106% (Cu), 100 – 105% (Cd), 88 – 103% (As(V)) e 96 – 106% (As(total)). Os resultados para Cu(II) determinados com os métodos propostos foram concordantes com os obtidos com o método comparativo. Conclui-se que o material produzido apresenta bom potencial para ser aplicado na extração/pré-concentração de cobre, cádmio e análise de especiação inorgânica de arsênio. Provou-se também que baixos limites de detecção e quantificação podem ser obtidos mesmo utilizando uma técnica menos sensível como a FAAS.
This paper reports on the development of analytical methods for the determination of some toxic and potentially toxic species in ultra - trace levels in natural water samples using a less sensitive analytical technique such as flame atomic absorpti on spectrometry (FAAS). This technique was chosen because it is relatively simple and has a low operating cost. The solid phase extraction technique (SPE) using a new sorbent material was used to separate and preconcentrate the analyte. This study demonstr ates the procedure of a new synthetic route using the technique of the co - condensation for the production of a mesoporous organo - functionalised silica with the 4 - amino - 3 - hydrazino - 5 - mercapto - 1,2,4 - triazole ligant and its use as a sorbent for preconcentrati on/ analysis of metal ion s speciation in water samples. The material produced was characterized by infra - red spectroscopy (FTIR), BET, 29 Si and 13 C nuclear magnetic resonance (NMR), among others. The adsorptive characteristics of this material were establis hed in batch studies, where the effect of pH, adsorption kinetics and maximum adsorption capacity were studied. Multivariate optimization was used to obtain the best chemical and flow conditions in the preconcentration system, allowing the evaluation of th e main and secondary interactions among the factors. By means of the analysis of the spectra obtained by FTIR, it was possible to observe C - H, C - Cl and (NH 2 ) stretch bands from the organic fraction of the material. The surface area was 369.84 m 2 g - 1 with a verage pore diameter at 7.1 nm related to mesoporous materials. The results obtained by 29 Si NMR prove the formation of the hybrid material, synthesized by co - condensation, and the 13 C NMR confirms the anchoring of the ligan t in the matrix. The pH 5.0 it w as favors the adsorption of the ions Cu (II), the pH 3.0 it was favors the adsorption of the Cd (II) and As (V). The kinetic model of pseudo second order showed better adjustment to the experimental data, indicating chemical adsorption. The adsorption data of Cu (II), Cd (II), and As (V) were similar to those of the Langmuir model, with a maximum adsorption capacity of 0.057, 0.018 and 0.060 mmol g - 1 for Cu (II), Cd(III) and As(V) , respectively, indicating that the sorption occurs in monolayer. The analyt ical parameters for Cu (II) were: preconcentration factor of 18.1; linear range of 10.0 - 200.0 μg L - 1 (R = 0.999) and LD of 1.45 μg L - 1 . For Cd (II): preconcentration factor of 15.8; linear range of 2.0 - 100.0 μg L - 1 (R = 0.999) and LD of 0.38 μg L - 1 . Fo r As (V): preconcentration factor of 5.0; linear range of 0.25 - 2.5 μg L - 1 (R = 0.999) and LD of 0.039 μg L - 1 . Accuracy was checked by addi tion and recovery method of the standard and/ or comparative method with GFAAS or ICP OES. The recovery ranged from 97 - 106% Cu(II), 100 - 105% Cd (II), 88 - 103% As (V) and 96 - 106% As (total)). The results for Cu (II) determined with the proposed methods were concordant with those obtained with the comparative. It is concluded that the material produced can be successfully applied in the extraction / preconcentration of copper, cadmium and analysis of inorganic speciation of arsenic and low limits of detection and quantification can be obtained even using a less sensitive technique such as FAAS.

Zinc oxide nanoparticles (ZnO NPs) have unique physical and chemical characteristics which deviate from larger particles of the same material, due to their extremely small size, higher specific surface area and surface reactivity. The peculiar properties of ZnO NPs could potentially improve zinc (Zn) fertilizers for sustainable agriculture. This is based on the assumption that ZnO NPs provide a more soluble and bioavailable source of Zn in soil compared to micron- or millimetre- sized (bulk) ZnO particles currently used for Zn fertilizers in Zn deficient soils. However, a thorough understanding of the fate and reactions in soils and interactions of nanoparticles with plants of ZnO NPs is required prior to the recommendation for use of these novel materials. Therefore, there is a need to investigate dissolution, diffusion, transformation, partitioning and availability of manufactured ZnO NPs in soil to ensure safer and more sustainable application of ZnO NPs as a new source of Zn fertilisers for plants, and better management of their potential risks. Given inclusion of Zn in macronutrient fertilizers is the common procedure for their field application, ZnO NPs and bulk ZnO were coated onto macronutrient fertilizers (monoammonium phosphate (MAP) and urea) and dissolution kinetics, diffusion and solid phase speciation of Zn from coated fertilizers were evaluated. Coating of ZnO on macronutrient fertilizers significantly affected solubility and dissolution kinetics of the ZnO sources, but nano-sized ZnO did not show any enhanced solubility over bulk ZnO. The low pH value of ZnO-coated MAP granules resulted in greater and faster dissolution of ZnO compared to ZnO-coated urea granules. However, interactions of ZnO particles with phosphate in MAP granules likely resulted in precipitation of Zn-phosphate species. The high pH and ionic strength of the dissolving solution resultant from hydrolysis of urea likely promoted aggregation of any ZnO NPs released from coated urea granules and also hindered dissolution of ZnO. To evaluate changes in Zn speciation with coating of the ZnO sources and after incorporation of the coated-fertilizers into an alkaline calcareous soil, synchrotron-based micro X-ray absorption fine structure (μ-XAFS) method was used. The findings confirmed precipitation of Zn-phosphate species at the surface of MAP fertilizer granules irrespective of the size of ZnO particles used for coating. For coated urea, the Zn remained as ZnO species for both nano-sized and bulk ZnO coatings. Solid phase speciation in the fertilized soil varied with distance from the point of fertilizer application. Significant amounts of Zn(OH)₂ and ZnCO₃ species were identified in the soil some distance from coated urea and MAP, respectively, indicating dissolution/precipitation processes were active. Moreover, limited and comparable diffusion of Zn from coated fertilizers with nanoparticulate or bulk ZnO into soil was observed using micro x-ray fluorescence mapping (μ-XRF). Transformation of Zn at the surface of MAP granules, mass flow of water towards the hygroscopic fertilizer granules or strong aggregation of ZnO nanoparticles released from urea granules could have been the mechanisms which restricted Zn diffusion. Given that coating of ZnO on macronutrient fertilizers markedly reduced Zn solubility, reactions of ZnO NPs and bulk ZnO in soil were studied when applied as the pure oxides. Availability of Zn for durum wheat (Triticum durum) plants from nanoparticulate and bulk sources of ZnO was evaluated in an acidic and an alkaline soil using an isotopic dilution procedure (L value). Significant dissolution and plant acquisition of Zn from ZnO was observed (ca. 50 – 100 % of added), even with limited pre-incubation of soils with the Zn sources. However, no significant effect of particle size was observed on plant acquisition of Zn from the ZnO. Retention and dissolution of ZnO NPs and dissolved Zn species from ZnO NPs was further investigated in five soils with diverse physical and chemical properties. Strong retention of ZnO NPs and/or dissolved Zn species from ZnO NPs was found in all soils especially in alkaline and calcareous soils. The adsorption affinity of ZnO NPs was generally greater than that of soluble Zn, which suggested ZnO NPs were retained more strongly than soluble Zn in soils. Soil pH and clay content of soil were the most important soil properties affecting retention, although the number of soils used was too small to draw firm conclusions as soil parameters co-varied. Generally, nanoparticulate forms of ZnO appear to offer little advantage over bulk-sized ZnO as a source of fertilizer Zn to crops. Rapid dissolution of ZnO NPs and partitioning of dissolved Zn species derived from ZnO NPs and/or high retention of ZnO NPs in soils suggested that soil application of manufactured ZnO NPs would not appear to offer any benefits over bulk ZnO, whether applied in pure form or along with macronutrient fertilisers. However, from an ecotoxicological point of view, ZnO NPs would not be persistent in soil systems and hence their mobility in soil would be limited. Therefore the risks associated with application of ZnO NPs in soil would be similar to that of soluble Zn.
Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2012

博士
國立中正大學
化學工程研究所
101
Renewable and hydrogen energy are considered solutions for future energy. Solar energy has attracted increasing attentions. Combining these two fields, photocatalyst technology has become an important research area; for example, hydrogen generation from water splitting, methane synthesis and methanol synthesis etc. The solid solutions of Ag-In-Zn-S (AIZS), Cu-In-Zn-S (CIZS) and Ag-Cu-In-Zn-S (ACIZS) with adjustable band gaps possess high hydrogen production activities. However, thin film fabrication process was restricted to the high-temperature thermal treatment (850 °C) leaded to the damage of ITO glass substrate. The hydrogen production rate is related to the band gap of photocatalyst. Generally, the optimal band gap was believed approximated 2.3 eV for these materials. Our investigation stared with wurtzite ZnS, the same phase type with AIZS. The formation temperature of AIZS is expected to be lower than 850 °C when the phase transformation of ZnS is absence. The transition temperature of wurtzite type for pure ZnS is rather high, as 1020 °C. Although there were many articles reporting synthetizing WZ-ZnS at lower temperatures, it was very difficult to obtain WZ-ZnS high-purity. This study controlled the levels of ZnO content in the final products by different amounts of NaOH, WZ-ZnS can be obtained after annealing at 350 °C ~ 700 °C. As opposed to the temperature reduction induced by a smaller particle size, this research pointed out that the existence of ZnO is another critical factor to reduce the processing temperature. Unfortunately, the temperature reduction of AIZS formation is only 50 °C when we utilize WZ-ZnS as a seed to start the reaction. This result drove us to modify our strategy from a chemical bath deposition to the electrophoretic deposition. The annealed powders were deposited on subtracts directly, and the photocurrent of 0.137 mA/cm2 can be obtained successfully in a sacrificial reagent with Na2S and K2SO3. We also varied the compositions of AIZS by increasing the indium content. The indium-rich samples did not induce phase separation between AgxInxZnyS2x+y and AgIn5S8, instead forming a single-phase solid solution. Compared to the steady H2 evolution rate of Pt-loaded photocatalyst obtained with equal moles of indium and silver, that obtained with In-rich photocatalyst is over 5.86 times higher even though the band gaps were fixed. This study demonstrates the interaction, Pt loading and In2S3, played more critical role than band gap on the hydrogen production rate. We further synthesized the crystalline powders of AIZS, CIZS, and ACIZS by solid-state reaction. The H2 evolution rates were compared with the same condition (sacrificial reagent, co-catalyst, luminescence intensity and temperature). UV-Vis spectra and Ultraviolet Photoelectron Spectroscopy (UPS) were employed to identify the Fermi level, valence band and conduction band edges of each samples. These data provide additional information for the physical origin of high-efficiency photocatalyst. Based on the aforementioned findings, the property of band gap adjustable in AIZS, CIZS and ACIZS can be used to tune the relative levels of energy band between the photocatalyst layer and the barrier layer. This strategy can be applied to restrain the photocorrosion and enhance the photocurrent in the future.

Two related techniques, based upon ion-exchange solid phase extraction, have been developed for the determination of arsenic speciation. The inorganic arsenic species arsenite (As(III)) and arsenate (As(V)) are separated by anion-exchange and detected with graphite furnace atomic absorption spectrophotometry (GFAAS) with a nickel matrix modifier. The first separation technique, which is based on a published method, utilizes a strong anion-exchange resin in a column format. The method was refined to achieve a cleaner and more rapid separation of the As species. In the second separation technique, the recently available Empore[superscript TM] anion-extraction disks are used. In both cases, rapid separations of several samples are achieved with the use of a vacuum manifold. The simplicity of the separation techniques allows them to be applied in the field which eliminates potential problems due to sample storage. In the pH range of most natural water samples (5-9), As(III) exists as a neutral species which is not retained by the resin, while As(V) exists as a monovalent or divalent species which are subsequently retained by the resin. The two arsenic species are collected in 3 to 4 fractions with As(III) appearing in the first two fractions. The As(V) species is eluted from the resin with 0.1 M HCl and collected in the last one or two fractions. Percent recoveries for each species range from 94 to 99%. The detection limit for each species with GFAAS is 2 ��g/L. The speciation techniques were used successfully in several applications. First, the resin technique was used to monitor the oxidation of As(III) by 0���, H���0���, and ��-Mn0���. The technique was also used to monitor the reduction of As(V) by Fe(II) and in solutions containing combinations of Fe(II), Fe(III), and a scorbic acid. Second, the resin technique was used to monitor the redox behavior of arsenic in soil slurries in bio-reactor systems. Upon spiking the soil slurry to a level of 500 ��g/L As(V), 80 to 90% of the As(V) was immediately adsorbed, presumably to hydrous Fe(III) oxides. In general, as conditions became more reducing, total soluble arsenic increased as a result of either abiotic or biotic reduction of the As(V) to the more soluble As(III). Third, the disk technique was applied in the field to determine arsenic speciation in creek water at Sutter Creek, Ca., where homes are built upon a large pile of mine tailings containing arsenic. In the creek water, no As(III) was detected but As(V) was detected at a level of 8 ��g/L. Fourth and finally, the resin technique was used to determine arsenic speciation when a sample of the mine tailings was placed in a reactor and combined with a soil slurry thus simulating a flooded condition. As conditions became more reducing, up to 800 ��g/L As was detected in solution with As(III) accounting for almost 90% of total soluble species. Also presented here is an investigation of zinc amalgam as a reducing agent for Cr(III) and selected redox indicators. Zinc amalgam, in a column format, also known as the classic Jones Reductor, provides an efficient means for production of Crap and reduced forms of various redox indicators. Finally, the reduction capabilities of Ti(III) citrate and zinc amalgam were compared.
Graduation date: 1996

Biopharmaceutics Classification System (BCS) class II and IV drugs may be formulated as supersaturating drug delivery systems (e.g., amorphous solid dispersions [ASDs]). The mechanisms that contribute to the increased bioavailability of these systems are generally attributed to the increased solubility of the amorphous form but another mechanism, with significant contributions to the improved bioavailability has been recently identified. This mechanism is related with the formation of colloidal species that are able to improve the bioavailability several fold beyond that of the amorphous drug alone. These species occur when the concentration of drug generated in solution exceeds the amorphous solubility during dissolution, resulting in a liquid-liquid phase separation (LLPS). This work intended to implement a screening methodology to understand the ability of a drug to form colloidal species in a biorelevant dissolution media. This screening strategy was therefore focused on following the colloidal formation of itraconazole (ITZ; model drug from BCS class II) in the presence of hydroxypropyl methylcellulose acetate succinate (HPMC-AS) L, HPMC-AS M and HPMC-AS H (HPMC-AS with varying ratios of succinoyl:acetyl groups), using UV absorbance and a laser diffraction-based methodology. The ability of ITZ to form colloids by a solvent-shift approach was compared with the actual colloidal formation of ITZ amorphous solid dispersions produced by spray-drying (SDD). Results indicate that regardless of the used methodology to form supersaturated solutions of ITZ, colloids could be detected and monitored. The extension of colloid generation showed to be correlated with the SDD disintegration/dissolution rate, i.e, polymers with faster wettability kinetics led to faster SDD disintegration and colloidal formation. As conclusion, this study showed that both laser diffraction and UV absorbance could give complementary information about colloidal formation and SDD dissolution profile, showing to be an excellent screening strategy to be applied in the early stage development of amorphous solid dispersions.

博士
高雄醫學大學
醫學研究所
101
This study describes the development of analytical methods that used nano-TiO2 solid-phase extraction/separation coupled with flow injection (FI)－atomic absorption spectrometry (AAS) for heavy metal speciation. The proposed nano-TiO2 solid-phase extraction/separation－FI－AAS system was validated and applied to the detection of heavy metal species in human urine and environmental water samples. Three methods are presented in this study. Firstly, an on-line nano-TiO2 solid-phase extraction/separation coupled with FI－electrothermal AAS (ETAAS) system was developed for the separation of Se(IV) and Se(VI) in urine samples. The 0.02 M NaOH solution was used to elute the Se(IV) and Se(VI) species from the surface of nano-TiO2 film reactor and the eluent was introduced into the graphite tube by a flow injection system. The detection limits was 0.31 μg L-1 and 0.25 μg L-1 for Se(IV) and Se(VI), respectively. The precisions of the developed method for Se(IV) and Se(VI) were in the rages of 2.1 - 7.4%. The recoveries of Se(IV) and Se(VI) in urine samples were in the rages of 93.9 - 112.2%. The average concentrations of Se(IV) and Se(VI) in urine of patients with diabetes mellitus were found to be 5.7 and 10.5μg L-1, respectively. In subsequent part, an on-line nano-TiO2 photocatalysis reduction device coupled with FI-ETAAS was developed for chromium speciation. The process of chromium speciation in urine was based on the adsorption of Cr(III) and Cr(VI) on this photocatalysis reduction device. The absorbed Cr(VI) was photoreduced to Cr(III), and Cr(III) was eluted using 1.0 M formic acid. The detection limit for Cr(III) and Cr(VI) using this analytical method was 0.08 and 0.13 μg L-1, respectively. The precisions for the analysis of Cr(III) and Cr(VI) were in the range of 4.0 - 6.2%. The spiked recoveries were in the range of 96.0 - 98.3% for the determination of Cr(III) and Cr(VI). This analytical method was applied to the determination of Cr(III) and Cr(VI) in urine samples of human volunteers, during which samples were taken before and after the volunteers’ diets supplemented with chromium picolinate. Lastly, due to the complexity for separating the four arsenic speciesof interest, an analytical method was developed for the determination of them in environmental water samples using a nano-TiO2 solid-phase extraction/separation coupled with atomic absorption spectrometry. The separation of the four arsenic species was based on the selective adsorption of arsenic species onto the surface of TiO2 film at pH 3 or 10 and their subsequent selective desorption through elution with 50 mM NH4H2PO4, 50 mM (NH4)2C2O4 and 50 mM CH3COONH4 solution. The detection limits for As(III), As(V), MMA, and DMA was 0.17, 0.18, 0.14, and 0.11 μg L–1, respectively. The precisions of this analytical method for four arsenic species were in the range of 0.7 - 8.1%. The recoveries for As(III), As(V), MMA, and DMA spiked in water samples were in range of 90.4 - 107.3%. This proposed method was successfully applied for the speciation of four arsenic species in well water samples. In summary, the results of this study confirmed that a nano-TiO2 solid-phase extraction/separation coupled with atomic absorption spectrometry would be a novel and foresighted method for trace metal speciation and could benefit the exploration of trace heavy metals in biomedicial and environmental sciences.

Przygotowanie próbki do analizy specjacyjnej jest trudnym zadaniem, praktycznie każda próbka i każdy analit wymagają osobnych scenariuszy analitycznych. Arsen, chrom oraz tal należą do grupy pierwiastków znajdujących się na liście priorytetów badawczych Amerykańskiej Agencji Ochrony Środowiska (US EPA). Analiza specjacyjna szeregu pierwiastków jest istotnym elementem nowoczesnego monitoringu środowiska, ponieważ ich toksyczność, mobilność, czy biodostępność zależy od stopnia utlenienia oraz formy chemicznej. Do najbardziej toksycznych form As należą połączenia nieorganiczne, natomiast organiczne związki arsenu są nietoksyczne. Związki Cr(III) są mniej rozpuszczalne i bardziej stabilne w naturalnym wodnym środowisku, podczas gdy związki Cr(VI) są bardziej rozpuszczalne i mobilne. Związki Tl(III) są bardziej toksyczne niż związki Tl(I). Woda, jako abiotyczny element środowiska naturalnego odpowiada za transport zanieczyszczeń oraz zmianę form specjacyjnych pierwiastków. Wodę można podzielić na frakcję rozpuszczoną, która odpowiada za transport zanieczyszczeń oraz fazę zwieszoną (SPM), która jest odpowiedzialna za współstrącanie form chemicznych As, Cr oraz Tl. Zebrano próbki wód zawierających związki powierzchniowo czynne oraz sprawdzono powinowactwo wybranych form As, Cr i Tl do zawiesiny (SPM). Formy specjacyjne rozdzielono i zatężono z wykorzystaniem ekstrakcji do fazy stałej. Zastosowano różne sorbenty m.in. SGX C18 modyfikowany pyrolidynoditiokarbaminanem amonu (APDC) oraz tlenek glinu modyfikowany dodecylosiarczanem sodu (SDS). Sprawdzono możliwość wydzielania As(III), Cr(III) i Tl(III) z wody. Jednak tylko dla Tl(III) zaproponowano kompletną procedurę wydzielenia i zatężenia Tl(III) z matrycy wody. Następnie sprawdzono możliwość wykorzystania fotokatalizatorów tritlenku wolframu oraz tritlenku diżelaza do rozłożenia surfaktantów przed analizą specjacyjną. Zaproponowano różne warstwy aktywne składające się z fotokatalizatorów tlenków wolframu i żelaza. Płytki te oceniono podczas rozkładu SDS oraz Tritonu X-114, gdzie sensorem był układ elektroda rtęciowa i oznaczanie śladowych ilości Pb(II). Wybrane fotowarstwy sprawdzono w degradacji związków organicznych przed analizą specjacyjną arsenu, chromu i talu. Opracowano pełną procedurę od pobrania próbki do analizy związków As i Tl w wodach o dużej zawartości związków powierzchniowo czynnych. Scenariusz analityczny oparty na fotokatalizie mógłby być włączony w nowoczesną analizę środowiskową.
Sample preparation for speciation analysis is a difficult task, practically each sample and each analyte requires unique analytical scenarios. As, Cr i Tl belong to the group of elements included in the list of research priorities of the American Environmental Protection Agency (US EPA). Toxicity, mobility, or bioavailability of many elements depend on their oxidation state and chemical form. For this reason speciation analysis is an important element of modern environmental monitoring. The most toxic forms of As are inorganic compounds, while organic arsenic compounds are non-toxic. Cr(III) compounds are less soluble and more stable, while Cr(VI) compounds are more soluble and mobile in the natural aqueous environment. Tl(III) compounds are more toxic than Tl(I) compounds. Water, which is an abiotic element of the environment, is responsible for transport of pollutants and changes of the speciation forms of elements. Water can be divided into two phases: dissolved phase which is responsible for the transport of pollutants and suspended particulate matter (SPM) which is responsible for co-precipitation of chemical forms of As, Cr and Tl. Water samples containing surface active compounds were collected. The affinity of selected As, Cr and Tl forms for SPM was checked. The speciation forms were separated and preconcentrated using solid phase extraction. Various sorbents have been applied, e.g. SGX C18 modified with ammonium pyrolidinedithiocarbamate and alumina modified with sodium dodecyl sulphate (SDS). The possibility of simultaneous separation of As(III), Cr(III) and Tl(III) from water was tested. However, a complete procedure was developed only for separation and preconcentration of Tl(III) from the water matrix. Next, the possibility of application of photocatalysts: tungsten and iron oxides for decomposition of surface-active compounds before the speciation of As, Cr and Tl was tested. Different active layers consisting of tungsten and iron oxides have been proposed. These active layers were evaluated during the decomposition of SDS and Triton X-114. Decomposition efficiency was evaluated on the basis of voltammetric determination of trace amounts of Pb(II) with a mercury electrode, which is very sensitive to interferences from organic compounds. Selected photolayers were tested in the degradation of organic compounds before speciation analysis of arsenic, chromium and thallium. A complete procedure (from sampling to determination) for analysis of As and Tl compounds in waters with high content of surfactants was developed. Analytical scenarios based on photocatalysis could be included in the modern environmental monitoring.

Wprowadzenie do powszechnego użytku katalizatorów samochodowych spowodowało wzrost emisji metali z grupy platynowców (PGE) do środowiska. Podwyższony poziom zawartości platyny, palladu i rodu jest obserwowany szczególnie w okolicach dużych szlaków komunikacyjnych, rzadko jednak przekracza 1 μg g-1. Celem pracy doktorskiej było określenie wpływu, jaki pierwiastki z tej grupy wywierają na środowisko. Aby to było możliwe konieczne jest dysponowanie metodami gwarantującymi zarówno oznaczanie całkowitych zawartości analitów na odpowiednich poziomach stężeń, jak i śledzenie przemian jakim ulegają i identyfikację ich form chemicznych. Aby uzyskane wyniki oznaczeń były wiarygodne należy szczególną uwagę zwrócić na sposób przygotowania badanych materiałów do analizy. Pod względem analitycznym, oznaczanie śladowych ilości platyny, rodu czy palladu w próbkach środowiskowych nie jest zadaniem prostym. Złożoność matrycy próbek oraz niski poziom stężeń sprawiają, że metody oznaczeń muszą charakteryzować się odpowiednio niskimi granicami oznaczalności. Często w procedurze analitycznej wprowadza się dodatkowy etap zatężania analitów i uproszczenia matrycy próbki. W ramach prowadzonych badań zoptymalizowano procedury roztwarzania próbek gleb i piasków kwarcowych z wykorzystaniem mieszaniny kwasów HNO3 i HCl. W oparciu o wyniki uzyskane dla certyfikowanego materiału odniesienia – pyłu drogowego BCR-723 wykazano efektywne przeprowadzenie PGE do roztworu. Do wydzielania analitów z matrycy wykorzystano metodę ekstrakcji do fazy stałej. W trakcie badań zastosowano sorbenty kationo- i anionowymienne oraz eluenty o różnej sile elucyjnej: 0,1 mol L-1 tiomocznik w 0,1 mol L-1 HCl, 2 mol L-1 HCl, 0,025-0,053 mol L-1 bufor amonowy. Opracowane procedury przygotowania próbek zastosowano do monitorowania PGE w próbkach gleb i piasków kwarcowych, pobieranych z poletek monitoringowych rozmieszczonych wzdłuż ciągów komunikacyjnych i eksponowanych na zanieczyszczenia związane z ruchem drogowym. Szczególną uwagę zwrócono na możliwość zastosowania w oznaczeniach metody woltamperometrii inwersyjnej z adsorpcyjnym zatężaniem (AdSV), która, ze względu na niskie granice oznaczalności może być alternatywą do metody spektrometrii mas z plazmą indukcyjnie sprzężoną (ICP MS). Na podstawie uzyskanych wyników wykazano wpływ ruchu drogowego na wzrastające skażenie środowiska oraz wskazano katalizatory samochodowe, jako główne emitery pierwiastków z grupy platynowców. Odkładanie się PGE w glebach sprawia, że mogą być one pobierane i akumulowane przez rośliny, co może powodować zaburzenia ich prawidłowego funkcjonowania. W oparciu o materiał roślinny pozyskany w ramach upraw hydroponicznych określono wpływ platyny, palladu i rodu na rozwój gorczycy białej (Sinapis alba L.). Rośliny narażone na stres związany z obecnością różnych soli i nanocząstek PGE zostały scharakteryzowane pod kątem całkowitej zawartości metali pobranych z pożywki i przetransportowanych do części nadziemnych (ICP MS), obecności nanocząstek w wybranych tkankach (SP ICP MS, TEM), jak i tworzenia kompleksów z ligandami obecnymi lub syntezowanymi de novo w roślinie. Powstałe w tkankach fitochelatyny (PC2, PC3 i PC4) zidentyfikowano metodą wysokosprawnej chromatografii cieczowej z detekcją fluorescencyjną (HPLC FLD) oraz spektrometrią mas z jonizacją przez elektrorozpraszanie (ESI MS). Dodatkowo dzięki wykorzystaniu metody SEC ICP MS, wykryto i rozdzielono grupy związków palladu powstających w komórkach Sinapis alba L. Z kolei zastosowanie metody HILIC ESI MS umożliwiło zidentyfikowanie wybranych połączeń Pd z ligandami organicznymi, jak histydyna i nikotianamina, odpowiedzialnymi za procesy detoksykacji metali.
Introduction of car catalysts for general use caused an increase in emissions of platinum group elements (PGEs) to the environment. The increased level of platinum, palladium and rhodium is observed, especially in the vicinity of main communication routes, but still, rarely exceeds 1 μg g-1. The aim of the doctoral thesis was to determine an impact which PGEs may have on the environment. To make that possible, it's necessary to develop procedures, guaranteeing both, determination of the total content of analytes at appropriate concentration levels, as well as monitoring the changes they undergo and identification of their chemical forms. In order to get the reliable results, particular attention should be paid to the proper way of sample preparation before analysis. The determination of trace amounts of platinum, rhodium or palladium in environmental samples is not a simple task. The complexity of the sample matrix and the low concentration level of analytes cause that the determination methods must have sufficiently low limits of quantification. Often an additional step of analytes pre-concentration and separation from the matrix is introduced in the analytical procedure. As a part of the conducted research, the digestion procedures of soil and quartz sands samples, using the mixture of HNO3 and HCl acids, were optimized. Based on the results obtained for certified reference material (BCR-723; road dust) the possibility of efficient analytes transfers into the solution was proven. To isolate analytes from the matrix the solid phase extraction method was suggested. During the experiments, cation and anion exchange sorbents, as well as the eluents of various elution strength were used: 0.10 mol L-1 thiourea in 0.10 mol L-1 HCl, 2.0 mol L-1 HCl, 0.025-0.053 mol L-1 ammonium buffer. Developed sample preparation procedures were used to monitor PGEs in soil and quartz sands samples received from the monitoring plots distributed along high-ways and exposed to traffic-related contamination. Particular attention was paid to the possibility of using adsorptive stripping voltammetry (AdSV), which, due to low limits of quantification, can be an alternative method to inductively coupled plasma mass spectrometry (ICP MS). Based on the results obtained, the influence of road traffic on the increasing environmental pollution was proven, along with the indication of car catalysts as main emitters of the platinum group elements. The deposition of PGEs in soils makes that they can be taken up and accumulated by plants, which may cause disturbances in their proper functioning. The influence of platinum, palladium and rhodium on the growth of white mustard (Sinapis alba L.) was defined based on the plant material obtained from hydroponic cultivation. The plants, exposed to stress from the presence of various salts and nanoparticles of PGEs, have been characterized for the total content of metals taken from the nutrient solution and transported to aboveground organs (ICP MS), the presence of nanoparticles in selected tissues (SP ICP MS, TEM) and the formation of complexes with ligands present or de novo synthesized in the plant. The phytochelatins (PC2, PC3 and PC4), formed in plant cells, were identified by high-performance liquid chromatography with fluorescence detection (HPLC FLD) and electrospray ionization mass spectrometry (ESI MS). Additionally, thanks to the use of the SEC ICP MS method, some palladium compounds formed in Sinapis alba L. cells were detected and separated. The application of HILIC ESI MS method enabled identification of several Pd complexes with organic ligands, like histidine and nicotianamine, responsible for metal detoxification processes.