This research was able to identify a wide range of elements present in fresh volcanic ash from a 2010 eruption in Indonesia using varied instrumental neutron activation analysis techniques. The ash was then leached into slightly acidic distilled water meant to simulate rainwater. This thesis focuses both on the methods used to identify the elements present in the ash, as well as the possible impacts of the results. The research included the use of both thermal and epithermal neutron irradiations from the University of Texas's TRIGA research reactor in conjunction with a high purity germanium detector (HPGe) with a Compton suppression system. The leachate was analyzed by an inductively coupled plasma mass spectrometer (ICP-MS), and the results were compared to the original material present in the ash. Several potentially toxic metals and metalloids leached out of the system at relatively high rates. For example, 2.7% of the original antimony present in the ash leached into the simulated rainwater, as well as 1.7% of the original nickel, and 0.71% of the original arsenic. However, the concentrations of the elements identified in the ash were mostly similar to average crustal rock, and the concentrations of the elements identified in the leachate were not determined to be at toxic levels. The total amount of each element released during the eruption was also calculated based on the estimate of 160 million tonnes of ash released during the eruption, which was determined by a different study. / text

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

The radiological dispersal device (RDD) is a weapon of great concern to those agencies responsible for protecting the public from the modern age of terrorism. In order to effectively respond to an RDD event, these agencies need to possess the capability to rapidly identify the radiological agents involved in the incident and assess the uptake of each individual victim. Since medical treatment for internal radiation poisoning is radionuclide-specific, it is critical to identify and quantify the radiological uptake of each individual victim. This dissertation describes the development of automated analytical components that could be used to determine and quantify multiple radionuclides in human urine bioassays. This is accomplished through the use of extraction chromatography that is plumbed in-line with one of a variety of detection instruments. Flow scintillation analysis is used for ⁹⁰Sr and ²¹⁰Po determination, flow gamma analysis is used assess ⁶⁰Co and ¹³⁷Cs, and inductively coupled plasma mass spectrometry is used to determine actinides. Detection limits for these analytes were determined for the appropriate technique and related to their implications for health physics.

published_or_final_version / abstract / toc / Chemistry / Master / Master of Philosophy

Les déchets solides générés par notre société sont nombreux. Les cendres volantes sont des déchets solides produits lors de la combustion de déchets domestiques ou industriels dans des incinérateurs. Les cendres volantes sont également produites par la combustion du charbon dans les centrales à charbon. Les cendres volantes sont des résultats de ces combustions et représentent importante quantité de déchets produits chaque année par notre société. Les possibilités de recyclage de ces déchets sont nombreuses : dans la construction, l'industrie routière. Elles sont également stockées pour une utilisation ultérieure. Les origines différentes des charbons et déchets incinérés conduisent à une minéralogie et une composition élémentaire complexe. En tant que sous-produit le devenir des cendres volantes est important à déterminer, aussi la détermination de la composition élémentaire de ces cendres volantes est-elle indispensable.Les méthodes classiques de préparation des échantillons solides sont la minéralisation acide ou la fusion alcaline. Ces procédures prennent du temps et supposent l'utilisation de réactif, de plus la digestion complète n'est pas toujours assurée. Le risque de contamination par les réactifs employés est important au cours de ces méthodes classiques de préparation. Au cours de la dernière décennie, le développement d'analyse directe d'échantillons solides en utilisant des méthodes d'ablation laser a été important en raison de la nécessité de réduire le temps d'analyse et de réduire aussi la consommation de réactifs. Dans ce travail, deux méthodes basées sur l'ablation par laser seront étudiées pour l'analyse des cendres: Laser Induced Breakdown Spectroscopy (LIBS) et Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). La spectrométrie LIBS sera étudiée pour la détermination quantitative des éléments majeurs dans les échantillons de cendres alors que le couplage ablation laser ICP / MS sera employé pour détermination des éléments traces. L'optimisation de la sensibilité et les stratégies d'étalonnage sont les principaux problèmes traités dans ce travail. La préparation des échantillons et l'optimisation ont été effectuées pour déterminer les éléments tels que Al, As, Ba, Ca, Cr, Cu, Fe, Mg, Mn, Pb, Sr, V et Zn par les deux méthodes.Les performances analytiques telles que les limites de détection, justesse ont été obtenus à la suite d'optimisations appropriées des liants et de la sélection de l'étalon interne approprié. En conclusion, l'analyse directe de solides en utilisant les techniques basées sur l'ablation laser développées dans ce travail conduisent à une justesse acceptable pour la détermination des éléments majeurs et traces dans les cendres volantes

Facile procedures based on hyphenated ion-exchange chromatography (IEC) and inductively coupled plasma mass spectrometry (ICP-MS) were developed to determine conditional stability constants, speciate chromium species and investigate the reduction of Cr(VI). 1. Improvements were made to a method previously developed to determine the conditional stability constant, Kf’, and chelation number, n, using IEC-ICP-MS. This method allowed the accurate determination of the conditional stability constant of a simple system. However, the corresponding chelation number was significantly different to the expected value because the principal assumption, i.e. that the ligand was in excess, was not realized in the experimentation. Furthermore, it neglected complexes other than that formed with EDTA4-. By taking into account these factors, accurate Kf’ and n were obtained for Co-EDTA and Zn-EDTA systems. 2. A simple method was developed for chromium speciation analysis at sub-µg L-1 level in potable water by IEC-ICP-MS. Cr(VI) and Cr(III) were separated on IonPac® AG-7 guard column within 7.5 minutes using gradient elution with 0.1 M ammonium nitrate and 0.8 M nitric acid. H2 collision/reaction interface gas eliminated chlorine-based and carbon-based polyatomic interferences on Cr detection. Water samples were analyzed directly, without any pretreatment. The accuracy of the method was verified through accurate analysis of riverine water certified reference material. Limits of detection of 0.02 and 0.04 µg L-1 for Cr(VI) and Cr(III), respectively, were obtained. 3. This speciation analysis method was then used for kinetics studies of Cr(VI) reduction in acidified riverine water. Water was spiked with Cr(VI), with or without Cr(III), and evolution of each Cr species with time was monitored by speciation analysis, showing that the reduction of Cr(VI) was a pseudo first order reaction. By plotting the logarithm of the peak area ratio of the instant Cr(VI) concentration over that of the original spiking versus time, the reaction rate constant was obtained as the slope. The reduction rate increased with decreasing pH and increasing temperature. The activation energy of the reaction at pH 1.3 was calculated using an Arrhenius plot. This method offers the advantages of small sample consumption, minimal sample manipulation, and easy data interpretation. / Thesis (Ph.D, Chemistry) -- Queen's University, 2010-09-30 08:05:27.342

In this thesis, new approaches to direct trace metals analysis of solid samples by inductively coupled plasma spectroscopy were investigated using laser ablation and thermal vaporization systems for solid sample introduction of biological, environmental, and pharmaceutical samples. / Laser ablation with inductively coupled plasma atomic emission spectroscopy (ICP-AES) and inductively coupled plasma mass spectrometry (ICP-MS) was applied to pharmaceutical tablets. Precision of analysis depended on laser parameters and could be improved using signal ratios. The feasibility of using laser ablation-ICP-MS for detecting natural levels of mercury along a single human hair strand was also demonstrated. / As well, the use of an induction-heating electrothermal vaporizer (IH-ETV) coupled to an ICP-MS was successful in determining mercury concentrations in a single human hair strand. Methodologies for multielement analysis of powdered hair were also explored using IH-ETV-ICP-MS. While calibration by reference hair materials showed promise, calibration methods by liquid standards were not suitable for any element. Detection limits achieved for most elements were below natural levels found in human hair. / IH-ETV-ICP-AES was also applied to the analysis of analyze-laden chromatographic powder. This study showed potential problems that may arise due to the methodology taken to analyze such materials. Finally, recommendations for future investigations and methodologies for laser ablation and thermal vaporization are discussed.

The Neolithic and late Iron Age pottery from the settlement site of Pool, Sanday, Orkney, was studied on two levels. Firstly, a morphological and technological study was carried out to establish a sequence for the site. Secondly an assessment was made of the usefulness of X-ray Fluorescence Analysis, Inductively Coupled Plasma Spectrometry and Petrological analysis to coarse ware studies, using the Pool assemblage as a case study. Recording of technological and typological attributes allowed three phases of Neolithic pottery to be identified. The earliest phase included sherds of Unstan Ware. This phase was followed by an assemblage characterised by pottery with incised decoration, which was stratified below a traditional Grooved Ware assemblage. The change in pottery styles and manufacturing methods with the Grooved Ware indicated that it evolved elsewhere. Grass tempered and burnished pottery characterised the Iron Age assemblage. Pottery samples from all phases of the site were analysed by XRF and ICPS. In addition, pottery from late Iron Age sites in the area was analysed for comparison with the Pool Iron Age pottery. XRF and ICPS analyses did not distinguish between either different phases at Pool or different Orcadian sites. This was attributed to the similarities in geological deposits over much of Orkney and the variations which can occur within a clay source. A clay survey was carried out in the vicinity of the site, and samples taken for comparison with the Pool pottery. Identification of rocks and minerals in thin section, and grain-size analysis, indicated that the Pool pottery was made locally to the site, and that both primary and secondary clays were used. It was concluded that petrological analysis is more suitable than elemental analysis in the study of coarse wares.

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Thesis (Ph.D.)--University of Melbourne, School of Earth Sciences, 2006. / Typescript. Includes bibliographical references (leaves 179-193).