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Samples of soil have been taken from five different locations in Needle's Eye Scotland to establish the processes and conditions which govern the possible movement of radium through the natural environment at the site. The samples were analysed using gamma spectroscopy, powder X-ray diffraction (PXRD), loss on ignition, X-ray fluorescence (XRF), UV/visible spectroscopy, scanning electron microscopy (SEM), and ICP MS - OES to determine the quantity of radium at different areas in the site and examine whether the levels were associated with any particular organic and inorganic phase. Initial gamma spectroscopy measurements on samples taken from Needle's Eye highlighted some key challenges with the determination of radium by inference by using the measurement of the uranium series progenies, bismuth and lead. Equilibrium between 226Ra and the two progenies (²¹⁴Bi and ²¹⁴Pb) was not reached, despite long collection times due to loss of radon gas from the experimental container. Various containers including plastic and aluminium cans sealed with different substances (wax, tape and plastic encapsulation) were then trialled to eliminate radon loss and hence accurately determine the radium content as evidenced by equilibrium being reached. It was proven that aluminium canisters (sealed with wax, Teflon tape on the threads, Scotch tape and vacuum sealed plastic bags) produced the most reliable results since they minimised the radon loss when measuring radium indirectly. A method for measuring radium directly, including the determination of errors, which takes into account the overlap between uranium and radium emission lines in gamma spectroscopy, has been developed. The activity concentrations for the different samples collected from Needle's Eye (NE1 – NE5) varied significantly; ²²⁶Ra varied from 0.67x10² ± 0.05x10² to 26.67x10² ± 6.40x10² Bq kg⁻¹, ²¹⁴Pb varied from 0.25x10² ± 0.03x10² to 17.70x10² ± 2.00x10² Bq kg⁻¹ and ²¹⁴Bi varied from 1.63x10² ± 0.12x10² to 17.30x10² ± 0.70x10² Bq kg⁻¹. The average activity ratios of Ra/Pb and Ra/Bi were found to be 1.48 ± 0.15 and 1.84 ± 0.34 respectively and showed significant variance from the ratio expected at equilibrium without radon loss. Loss on ignition treatment (500 and 1000 °C) was performed at the five sites and varied significantly (3.2 – 39.1%). UV - Vis analysis of samples generated by creating equilibrated water from the samples and altering the pH, suggests that the natural organic matter present in the Needle's Eye soil samples is dominated by humin, followed by lesser amounts of fulvic and humic acids. Further investigation of the soil from Needle's Eye was conducted by characterisation of topsoil (NE4T) from the organic rich location of the site. Significant amounts of radium were found to be present in topsoil (~ 30x10³ Bq kg⁻¹). Loss on ignition treatment (500 and 1000 °C) on the topsoil recorded mass a loss of ~ 86%, and further CHN analysis reported a strong presence of carbon (~ 41%) suggesting that about half of the mass lost during loss on ignition experiments is associated with organic carbon and the rest is from carbonate and the breakdown of hydrated minerals. The relative high percentages for carbon, in topsoil, are not surprising when taking into account the natural origin of the samples and the background geology of the site which is dominated by the presence of limestone (CaCO₃), hornblende (Ca₂(Mg,Fe, Al)5(Al, Si)₈O₂₂(OH)₂), and granodiorite (rich in calcium). Sequential extractions were performed on topsoil and deeper soil from the organic rich locality and showed that radium at Needle's Eye is not associated with a single fraction. Approximatelly 80% (combined) of the radium was split between 4 fractions with the carbonate fraction (i.e. calcite (CaCO₃) and dolomite (CaMg(CO₃))), with iron and manganese oxides (i.e. ferrihydrite ((Fe³⁺)₂O₃·0.5H₂O), goethite (FeO(OH)), and hematite (Fe₂O₃)), with the organic fraction (i.e. humin), and with the residual fraction (i.e. silicates, feldspars, and sulfates). PXRD analysis of the bulk soil phases was only successful in identifying quartz (SiO₂), muscovite (KAl₂(AlSi₃O₁₀)(F,OH)₂) and chlorite (Mg,Al)₆(Si,Al)₄O₁₀(OH)₈) phases as well as poorly crystalline feldspar phases as inorganic components of the soil samples taken from Needle's Eye due to the large proportion of organic matter in the soil. Using Loss on Ignition at 500°C to remove the organic phases but retain the inorganics showed the presence of carbonate mineral phases, such as, calcite (CaCO₃) and sulfate containing phases such as anhydrite (CaSO₄); as expected since limestone is present in the geology of Needle's eye site together with gypsum (CaSO₄.2H₂O and baryte (BaSO₄). Furthermore, PXRD analysis of the topsoil sample after heating at 1000°C to crystallise out the poorly crystalline iron phases evidenced by sequential extraction indicated prominent phases are anhydrite, gehlenite (CaSi₂Al₂O₇), quartz (SiO₂) and magnesioferrite (MgFe₂O₄). PXRD analysis supported by XRF elemental analysis, which showed elevated concentrations for calcium, may also suggest the presence of anhydrite (CaSO₄), as well as calcite (CaCO₃) after the sequential extraction of the carbonate fraction. The sorption experiments that were performed using topsoil under three different conditions for the binary experiments (i.e. radium spiked equilibrated water with topsoil, radium spiked demineralised water with topsoil, and radium spiked demineralised water with prewashed topsoil). The distribution ratios for radium were reported to vary between 158.3- and 180.1- mL g⁻¹ suggesting that radium is not mobile under these conditions. Radium mobility was conducted by using column experiments in an effort to duplicate the environmental conditions of the Needle's Eye site. Therefore, topsoil was used in a column and radium spiked equilibrated water was passed through the column. In the analysis of the effluent fractions coming out of the column, radium was not detected and therefore it was concluded that radium is not mobile under these conditions.

Iodine-129 is a high-yield fission product of 235U and 239Pu; is produced in nuclear power plants and is therefore present in substantial quantities in radioactive wastes. In the environment, iodine exists as a range of species: iodate (IO3-), iodide (I-), elemental iodine (I2), HOI and organic species are the most common. The behaviour of iodine in the environment is linked to its speciation which can be affected by different factors such as pH, redox potential and enzymatic reduction. Previous research has shown that iodine speciation can determine its fate in the environment; however the mechanisms of redox cycling amongst the different species are not yet fully understood. This research project has focused on improving the understanding of the changes on speciation of iodine in sediment and mineral systems undergoing redox cycling reactions. The fate and changes in iodine speciation were studied under reducing and oxidising conditions, with all experiments conducted under circumneutral pH conditions. Overall the results showed that when microbial activity is promoted in a sediment system, iodate is reduced to iodide with the reduction occurring during manganese reduction. Further, when nitrate is present at high concentrations the reduction of iodate is retarded. A net release of native iodine from sediments was observed in all experiments conducted with sediments; confirming previous observations that sediment bound iodine is released from sediments under reducing conditions. Modest abiotic reduction of iodate was observed under manganese and iron reduction; and iodate reduction happened faster in a mixed system with iron and pure culture bacteria than solely by the pure culture alone or via abiotic reduction with Fe(II). When reduced experiments were exposed to air, concentrations of iodide decreased with no iodate ingrowth or losses in total iodine in solution. This suggested that iodide had been oxidised to intermediate species (I2, HOI) that were not detected, although this reaction has been described in past research. Finally, when no microbial activity is promoted, iodine remains as iodate which showed modest sorption onto sediment systems and Fe(III) oxide. Overall, these results highlight the important role that bacteria play in the reduction of iodate. This research also confirms that iodine speciation impacts on the fate of 129I throughout the environment, where it may be less mobile in an oxic environment than under reducing conditions. Moreover, some techniques of bioremediation (e.g. promoting metal reducing conditions) may cause the release of radioactive iodine to solution.

The application of ICP-MS to the fields of proteomics and genomics has arisen in part due to its ability to detect and quantify trace levels of S and P, which are major constituents in proteins and nucleic acids respectively. The development of collision/reaction cell technology and high resolution instruments has enabled these biologically important elements to be measured and quantified at the pg - ng ml-1 level. Despite these advances, the detection limits of P and S are still inferior compared to other elements. Oligonucleotides containing biotin functionality were labelled with Au nano-particles attached to a streptavidin protein to achieve site specific labelling, with 100% labelling efficiency. Each nano-particle contained ~86 Au atoms, resulting in an 882 fold signal enhancement for 24 base length oligonucleotides. However, this enhancement factor was only observed when one oligonucleotide bound to one nano-particle in a 1:1 ratio. Much lower Au labelling efficiencies and signal enhancements were observed when thiolated oligonucleotides were labelled with maleimide functionalised gold nano-particles. This was attributed to the extensive and difficult sample preparation steps that were required prior to labelling. The detection and quantification of adducts formed between DNA and the Pt anti-cancer drugs cisplatin and oxaliplatin were also investigated with ICP-MS. Acid digestion of the carbon based DNA matrix enabled Pt adducts to be quantified at low dose rates of 1 Pt atom per 1 500 000 nucleotides in ~12 μg DNA. Such sensitive mass spectrometric determinations could be employed in clinical tests to detect and quantify low level adducts formed in patients in-vivo. To complement ICP-MS analysis, electrospray ionisation linear ion trap mass spectrometry was employed to study the interaction of oxaliplatin with the four DNA nucleobases. Multiple stage mass spectrometry enabled detailed Pt-nucleobase adduct fragmentation pathways to be established. The method of DNA detection using P in conjunction with the collision cell, or cool plasma to form PO+ was also demonstrated and the limitations of the method, namely, polyatomic interferences and severe matrix effects were highlighted.

Abstract: Chronic exposure to arsenic from groundwater is one of the greatest public health concerns in the world, putting over 170 million people at risk of arsenic-related diseases, including cancer, diabetes, and cardiovascular disease. Although our understanding of the mechanisms by which arsenic induces these biological effects remains limited and unclear, it is known that the binding of arsenic to the thiol groups (R−SH) of cysteine residues in proteins is a contributing factor. The binding of arsenic to proteins may alter their conformation and stability and inhibit their function. This could impede the recruitment of and interaction with other proteins and DNA, resulting in unrepaired DNA and carcinogenesis. Studying the interactions between arsenic and proteins is indispensable for understanding how arsenic affects the body. A method combining size-exclusion high performance liquid chromatography (SE-HPLC) with inductively coupled plasma mass spectrometry (ICPMS) that enables the separation and detection of protein-bound arsenic and free arsenic was developed. Simultaneous detection of arsenic and sulfur oxides (from cysteine and methionine residues present in proteins) provided supporting information for the identification of the arsenic−protein complex. The quantitative ICPMS detection allowed for the determination of apparent binding constants. Using this method, the interactions between trivalent arsenicals and four proteins, hemoglobin, peroxiredoxin-1, high mobility group box 1 protein (HMGB1), and p53, have been characterized. Investigating the interaction between arsenic and hemoglobin from seven animal species (cow, guinea pig, human, mouse, pig, rabbit, and rat) aimed to address the interspecies differences seen in arsenic distribution, retention in the blood, and toxicity. Results demonstrated that rat hemoglobin generally has the highest affinity for trivalent arsenic of all the species studies. Studying the interactions between arsenic and p53 proteins aimed to determine how known amino acid mutations impact the ability of the protein to bind to transcription factor DNA. The developed HPLC-ICPMS method confirmed the binding of small amounts of PAOIII and MMAIII to wild type p53. The interaction between wild type or mutant p53 and its transcription factor DNA was investigated using an enzyme-linked immunosorbent assay (ELISA) to monitor the capabilities of the p53 proteins to bind DNA. The ability of various trivalent arsenicals to inhibit the interaction between p53 and DNA was studied by performing the assay in the presence or absence of arsenic, providing further insight into the possible mechanism of arsenic-induced carcinogenesis.

The advantages of high sensitivity, low detection, large dynamic range and multi-element/isotope capability for most elements in the periodic table have enabled inductively coupled plasma mass spectrometry (ICPMS) to become a popular technique for elemental analysis. However, there are challenges from sample loss, matrix effects, interferences, or contamination when applying this technique in various analysis. To explore methods for reducing these difficulties in ICPMS-based analysis, the first part of this thesis is focused on removing inorganic phosphate interferences for the determination of organophosphate nerve agent degradation products based on the detection of 31P+. Calcium chloride and ammonium hydroxide were chosen as the coagulant and for pH adjustment to remove inorganic phosphate interferences. Applications to apple juice and cola drink indicate that this method is suitable for enhancing the determination of organophosphate species in high inorganic phosphate matrices. The growing interest in metals and their biological functions have promoted the utilization of ICPMS in the biological area for trace element determination and metal-containing speciation studies. The remaining focus of this dissertation is to investigate and characterize the metal-protein associations in various biological systems, which is referred as metallomics. To achieve overall screening and sufficient confidence in protein identifications, state-of-the-art metallomics techniques via two-dimensional chromatographic separations in combination with elemental and molecular mass spectrometries were utilized. Two biological systems were studied with different purposes and possible applications. Human cerebrospinal fluid (CSF) from healthy control patients and patients who suffered subarachnoid hemorrhage and its complication, cerebral vasospasm was screened at different metal detection points (Fe, Ni, Cu, Zn and Pb) for molecular distribution patterns and was investigated for possible markers. The identification and comparisons across the three types of CSF resulted in six protein families of possible biomarkers, which are now possible focus areas to study further for predicting, diagnosing and treating the hemorrhage to preclude the debilitating or deadly vasospasm. Bacteriophage lambda was investigated for possible phage-metal association at proteome level. Of a large number of metals, Mn, Fe, Co, Ni, Cu and Zn were observed to best associate with lambda phage sample from SEC-ICPMS screening. Further identification indicates that gpE, gpD and gpV have the highest likelihood of association with these transition metals to provide valuable information for lambda phage engineered technologies.

The mass spectrometric characterization of protein:RNA cross-links is challenging due to the heterogeneity of the sample and the physical and chemical properties of the cross-link components. This dissertation aims at overcoming these challenges by developing an analytical approach for the selective detection and quantification of peptide-oligonucleotide heteroconjugates and protein:RNA cross-links. The methods developed were adapted from previous studies and take advantage of the dual nature of the cross-link, where one set of chromatographic conditions separate based on the peptide portion of the cross-link, while a complementary set of chromatographic conditions is used based on the oligonucleotide portion of the cross-link. These liquid chromatography (LC) conditions were optimized first using synthetic oligonucleotide:peptide heteroconjugates, and then scaled from capillary to conventional conditions to enable split flow and fraction collection. Scaling up the chromatography and applying a 1:100 split allows for detection of the phosphorus response via the ICPMS, while the majority of the fraction is collected for subsequent liquid chromatography with tandem molecular mass spectrum analysis. Inductively coupled plasma mass spectrometry (ICPMS) is a powerful analytical tool for element specific analysis. Instrumental advances, such as the collision/reaction cell (CRC), gave rise to monitoring a variety of previously unattainable elements, which include sulfur and phosphorus, while increasing the sensitivity of overall metal detection. Furthermore, ICPMS is capable of element-specific detection, where the intensity of the element is directly proportional to the element present in the sample allowing for quantification of elements of interest. In addition, ICPMS ionization is neither matrix- nor amino acid sequence-dependent, thus removing ionization issues most commonly seen in traditional mass spectrometry approaches.The methods were then applied to oligonucleotide:peptide heteroconjugates generated from cross-linking between messenger RNA (mRNA) and ribosomal protein S1 formed through 4-thiouridine as the cross-linking reagent, as they contain phosphorus (from the oligonucleotide) and sulfur (from the cross-linking reagent). The selective purification of ribosomal protein S1:leaderless mRNA cross-links using ICPMS allows for the purified fraction to be further analyzed by LC-MS/MS for sequence analysis. Once sufficient sample was collected, the cross-links were digested using nuclease P1 (to reduce the size of the mRNA mimic to a monomer) and the cross-link is then sequenced using collision induced disassociation to identify the amino acid residues in ribosomal protein S1 involved in cross-linking. This novel method will enable identification of the binding sites on S1 and provide pertinent information on how this ribosomal protein recognizes mRNAs lacking the Shine-Dalgarno sequence.

Many elements have been claimed as essential for health but their precise roles in life are largely uncharacterized. The increasing interests in the metals/metalloids within biological systems have been driving the fast growth of metallomics, a subject originated to establish the links between metals/metalloids and life. The foundation of metallomics relies on precise determination of biological metal(loid) species. The aim of this dissertation is characterization of such species, primarily metalloproteins, in various biological systems using innovative metallomics approaches. These include several multi-technique methods in which the traditional elemental speciation with HPLC-ICPMS (inductively coupled plasma mass spectrometry) and LC-MS/MS based proteomics were combined to meet the challenges of metalloprotein characterization in animals and plants. Two biologically important elements were intensively studied, zinc (Zn) in murine macrophages and selenium (Se) in plants. The metallomics study in macrophages revealed that Zn played a fundamental role in host defense against Histoplasma capsulatum infection, and a few Zn-binding proteins selectively responded to macrophage activation or the pathogen infection. The Se study elucidated the complete profiles of Se metabolites in kale (Brassica oleracea) and soybean (Glycine max) and more importantly, it discovered the first Se-containing protein in plants, the Se-containing Bowman-Birk proteinase isoinhibitor D-II [Glycine max] derived from the Se-enriched soybean. These findings not only opened new avenues to study Zn’s precise roles in immunity and Se-containing proteins in plants, but also lead the interactions between metallomics and other research areas, such as immunology and proteomics.

Monomethylmercury (MMHg) is the toxic form of mercury (Hg) that biomagnifies in food webs, and human exposure to MMHg occurs predominantly via consumption of fish. The primary source of MMHg to the marine environment is thought to be in situ sedimentary production by benthic microorganisms, namely sulfate-reducing bacteria (SRB). I collected sediments from the continental shelf (stations 2 and 6) and slope (station 9) of the NW Atlantic Ocean, and amended them with various inhibitor and promoter solutions to target specific functional groups capable of Hg transformations. I also added stable enriched Hg isotopes to quantify gross Hg methylation and gross MMHg demethylation, which were detected with inductively couple plasma mass spectrometry (ICPMS). Hg isotope results suggest that biotic methylation accounted for at least 60% of gross Hg methylation and 0-40% of gross MMHg demethylation. Methanogens probably did not have a major role in MMHg production or demethylation at any of the stations. Iron-reducers (FeRB) were not primary Hg methylators, but iron-reduction (via a Fenton-like reaction) or Fe(III) limitation appear to have influenced MMHg demethylation. Nitrogen cyclers possibly were important in Hg methylation and MMHg demethylation may have been limited by nitrate. SRB were likely important producers of MMHg in nearly all of the sediments. Results of this study support previous research that SRB are important Hg methylators in sulfate-rich, marine environments. This study also highlights the potential importance of iron and nitrogen cycling in MMHg demethylation in marine sediments.

The primary approach for the analysis of drinking water for heavy metals is through the United States Environmental Protection Agency’s Methods 200.7 and 200.8 for Inductively Coupled Plasma Optical Emission Spectroscopy and Inductively Coupled Plasma Mass Spectroscopy, respectively. One of the most prominent heavy metals that has been of focus, and led to a decrease in the maximum contaminate level for drinking water, is total arsenic. It is, however, important to quantify the levels of each arsenic species in drinking water due to their different toxicities. In this study, a routine method to test, separate, and thereby quantify both the organic and inorganic arsenic species in real world samples was accomplished. Specifically four arsenic species: arsenite, arsenate, monomethylarsonate, and dimethylarsinate were separated in under six minutes through the use of ion-pairing reverse phase chromatography hyphenated with inductively coupled plasma mass spectrometry. Using tetrabutylammonium hydroxide as the ion-pairing reagent on a C18 column, the separation was obtained and utilized with real world samples that were tested and quantified.

Cerebrospinal fluid (CSF) surrounds and serves as a protective media for the brain and central nervous system (CNS). This fluid remains isolated from other biological matrices in normal bodily conditions, therefore, an in depth analysis of CSF has the potential to reveal important details and malfunctions of many diseases that plague the nervous system. Because phosphorylation of a wide variety of proteins governs the activity of biological enzymes and systems, a method for the detection of 31P in proteins found in human cerebrospinal fluid by high-performance liquid chromatography (HPLC) coupled to inductively coupled plasma mass spectrometry (ICPMS) is described. Specifically, it is of interest to compare phosphorylated proteins/peptides from patients suffering from post subarachnoid hemorrhage (SAH) arterial vasospasms against CSF from non-diseased patients. HPLC provides a way to separate many of the components of the CSF matrix, while ICPMS allows for the simultaneous detection of various elements, specifically phosphorus, at high sensitivity. Because structural elucidation is lost in the ICPMS experiment, softer ionization techniques such as Electrospray Ionization (ESI) are thus utilized for potential protein/peptide identification. Database searching software (Spectrum Mill) is then used in this study as a means of identification and validation. SEC-ICPMS confirms the presence of phosphorylated peptides within normal CSF as well as vasospastic and non-vasospastic SAH CSF samples. Non-enzymatically digested samples with ESI-MS analysis, in conjunction with Spectrum Mill database searching, indicates a variance among phosphorylated protein species across the sample batches, however, no correlations are drawn between disease types and phosphoprotein presence or absence.

There is a multitude of contaminated waste sites worldwide due to anthropogenic activities. When assessing the potential toxicological effects of environmental contaminants, prior concern has dealt with simply quantifying the total concentration of the particular contaminating element. With the increasing awareness of the often significant differences in toxicity between the varying environmental contaminants, elemental speciation and percent distribution must be determined. Conventional remediation efforts have been effective in contaminant removal, but are generally very costly. As a result, phytoremediation, which utilizes plants, has recently gained popularity for removing contaminants from soil. It is also known that a toxic concentration of selenium and arsenic/mercury, if administered simultaneously, produce a nontoxic metabolite in a mammal. The studies in this dissertation utilize novel methodologies to speciate and monitor the interactions of selenium and environmental contaminants, arsenic and mercury, in plants. Eight predominant selenium and arsenic species were simultaneously separated using ion-pairing reversed phase liquid chromatography (IPRP) coupled with inductively coupled plasma mass spectrometry (ICPMS) and electrospray ionization ion trap mass spectrometry within 18 minutes and applied to river water, plant extract and urine matrices. The differences metabolic pathways, including location and identity, of selenium and arsenic species were elucidated after single and simultaneous supplementation in the Chlorophytum comosum, spider plant via size exclusion chromatography (SEC) and IPRP coupled to ICPMS. Although total elemental analysis demonstrates a selenium and arsenic antagonism, a compound containing selenium and arsenic was not found in the general aqueous extract of the plant.Increasing the difference between the voltage on the extraction lens and the octopole, plus using a positive voltage between the octopole and quadrupole provided the lowest sulfur detection limits using xenon as the collision reaction cell (CRC) gas in ICPMS. Energy discrimination is the predominant mechanism for removing the 32O2+ interference of 32S+. Optimization parameters were also suggested for a standard solution comprised of 52 elements, including sulfur. Similar detection limits were acquired when comparing Xe to He or H2 CRC gas with a general trend comparable to detection levels for He.Capillary reversed phase chromatography (capRPLC) and SEC were coupled to ICPMS to investigate the metabolic fate of mercury in conjunction with or exclusion of selenium in the Allium fistulosum. The data suggests a possible selenium-mercury association in a proteinaceous macromolecule which is not readily translocated to the aerial plant regions. Data from x-ray fluorescence mapping of a freshly excised root and capRPLC-ICPMS of homogenized root extract suggest the formation of a mercury-selenium species and a similarly structured mercury-sulfur species predominantly residing in the cell wall of the epidermal root tissue. Utilizing x-ray absorption near edge structure analysis, the local environment of mercury and selenium qualitatively coincided with the mercury-selenium species formed in a mammal via a Hg-Se-S(GSH) moiety. The local environment of mercury also coincided with (GS)2Hg.

Inductively coupled mass spectrometry has, over the years, been a useful tool for the analytical chemist through the capability to qualitatively and quantitatively determine the elemental composition of unknown inorganic substances. Identification has occurred in a large variety of sample matrices such as, water, soil, inks, and industrial wastes. Within the last decade the matrix of interest has expanded into the biological realm. The ability to separate these complex bio-matrices requires reverse phase separation and usually implies the use of an organic modifier in the mobile phase. Due to the nature of the argon plasma, the use of carbon based modifiers destabilizes the plasma at the standard flow rates, decreasing the available ionization energy and depositing carbon on the sampling cone, clogging the entrance into the mass spectrometer interface. Current research involves evaluating commercially available micro-flow nebulizers which can allow the introduction of organic modifiers for increased chromatographic resolution of sample analytes because of the much lower solvent load to the plasma. Comparisons of various capillary flow nebulizers and spray chamber configurations are presented. An in-house spray chamber designed by the author is also evaluated. Sensitive and selective techniques for detecting phosphorus- and sulfur- based analytes with an ICPMS equipped with an rf only driven octopole collision/reaction cell (CRC) are investigated. The first technique utilizes Xe gas to reduce and remove polyatomic interferences from 31P and 32S. The second uses an oxidation reaction to form new product ions, 31P16O+ and 32S16O+, to move elemental phosphorous and sulfur away from the mass range of elemental interferences.The remaining focus of this dissertation is to utilize these earlier experiments and data from interfacing capillary flows into the Ar plasma to establish a qualitative and quantitative method for antisense oligonucleotides. This study describes a method for the analytical separation of 21-24-mer oligonucleotides using an RP C18 capillary column. Spectral data are comprised of element specific 31P and 32S, found in the phosphorothioate oligonucleotide backbone. UV (DAD) and elemental 31P and 32S data are obtained simultaneously through direct coupling of the capillary HPLC system to the ICPMS.The scientific significance of the data contained in this dissertation developed a low ppt and reproducible Cr speciation method and lays the foundation for Cr speciation in more complex matrices. The establishment of five interfacing variations of capillary flow nebulizers and four different spray chambers on the 7500ce displayed total consumption sample introduction, without degrading plasma performance. The introduction of O2 into an octopole collision reaction cell for the first time in ICPMS analysis allows for additional applications in ICPMS ion-molecule chemistry and the possibility of using other reactive gases in the octopole (NH3, CH4). These studies for the first time, institute the use of element specific synthetic P/S tags in phosphorothioates and natural P tags in biological oligonucleotides to qualitatively and quantitatively detect their presence by ICPMS. The methodology generated an alternative way to quantitate oligonucleotides and assist in the advancement of clinical trails profiling metabolite and pharmacokinetic data for developing anti-sense oligonucleotides.

Tropical small mountainous rivers (SMRs) may transport up to 33% of the total carbon (C) delivered to the oceans. However, these fluxes are poorly quantified and historical records of land-ocean carbon delivery are rare. Corals have the potential to provide such records in the tropics because they are long-lived, draw on dissolved inorganic carbon (DIC) for calcification, and isotopic variations within their skeletons are useful proxies of palaeoceanographic variability. The ability to quantify riverine C inputs to the coastal ocean and understand how they have changed through time is critical to understanding global carbon budgets in the context of modern climate change. A seasonal dual isotope (13C & 14C) characterization of the three major C pools in two SMRs and their adjacent coastal waters within Puerto Rico was conducted in order to understand the isotope signature of DIC being delivered to the coastal oceans. Additionally a 56-year record of paired coral skeletal C isotopes (δ13C & Δ14C) and trace elements (Ba/Ca, Mn/Ca, Y/Ca) is presented from a coral growing ~1 km from the mouth of an SMR. Four major findings were observed: 1) Riverine DIC was more depleted in δ13C and Δ14C than seawater DIC, 2) the correlation of δ13C and Δ14C was the same in both coral skeleton and the DIC of the river and coastal waters, 3) Coral δ13C and Ba/Ca were annually coherent with river discharge, and 4) increases in coral Ba/Ca were synchronous with the timing of depletions of both δ13C and Δ14C in the coral skeleton and increases in river discharge. This study represents a first-order comprehensive C isotope analysis of major C pools being transported to the coastal ocean via tropical SMRs. The strong coherence between river discharge and coral δ13C and Ba/Ca, and the concurrent timing of increases in Ba/Ca with decreases in δ13C and Δ14C suggest that river discharge is simultaneously recorded by multiple geochemical records. Based on these findings, the development of coral-based proxies for the history of land-ocean carbon flux would be invaluable to understanding the role of tropical land-ocean carbon fluxes in the context of global climate change.

Elemental speciation is the investigation of the chemical form ofmetal and non- metal containing species in environmental and biologicalsystems for the determination of species specific essentialityand toxicity. Speciation analysis is performed by combining modernseparation techniques with state-of-the-art element specific massspectrometry. Separation techniques used in this work include: capillaryelectrophoresis (CE), high performance liquid chromatography (HPLC) andgas chromatography (GC). Inductively coupled plasma mass spectrometry(ICPMS) is the instrument of choice for ultra-trace elemental speciationanalyses due to the excellent sensitivity and selectivity specific to thismass spectrometer.Modern innovations in analytical instrumentationspecific for elemental speciation have provided researchers withresources for the development of new hyphenated techniques and analyticalmethods. The specific goal of this dissertation is to describe modernadvancements specific to elemental speciation.In the firstsection a novel interface coupling CE and hydride generation with ICPMSdetection for arsenic speciation is described. The novel concentrictube interface design allowed for the separation, hydride generation,and detection of four arsenic species in less than 10 minutes.The majority of this dissertation focuses on method development forthe analysis of organophosphorus chemical warfare agent (CWA) degradationproducts. Recent increases in worldwide terrorist activity as well as thethreat of chemical weapon attacks have led to the demand for rapid andreliable analytical techniques for CWA analysis. Methods utilizing bothHPLC and GC separation techniques couple with 31P elementspecific detection with ICPMS for the analysis of organophosphoruschemical warfare agent degradation products are described. These worksare the first to utilize 31P detection with ICPMS for theanalysis of chemical warfare agent degradation products.