Very early in the history of atomic emission spectroscopy (AES) it was understood to be a powerful analytical tool. Until the 1930's the usefulness of atomic spectroscopy was not utilized very extensively even though its fundamental power was understood. The breakthrough that placed it in the standard chemistry laboratory was the discovery and implementation of the photoelectric effect. Since this discovery there has been a revolution in atomic spectroscopy which has brought it from the role of a humble servant used for primary elemental screening to an outstanding leader in applications of elemental analysis. Atomic emission spectroscopy of complex samples has long suffered from matrix effects which result in overlapping of spectral lines, fluctuating backgrounds and changing conditions in the source. Investigations employing an echelle polychromator with a two dimensional solid state array detector show great promise in minimizing the effects of these interferences on multielement analyses of complex samples. The Charge Injection Device (CID) detector used exhibits many characteristics which make it uniquely qualified for simultaneous, multielement detection in AES. With only slight modifications to the optics of a commercial spectrometer and the employment of a CID detector, detection limits for a number of elements are quite favorable. Dynamic ranges of over seven orders of magnitude are obtainable with this experimental system. The reduction of matrix effects by utilizing the huge wealth of information available from over 60,000 individual detector elements are demonstrated through results from several complex matrix standards. This CID-polychromator system was also employed for the element selective detection of gas chromatographic (GC) effluents. A microwave-induced plasma (MIP) based on the Surfatron design was built. A helium plasma from this device has shown to have resilience to organic samples and give good emission response to non-metallic atoms. A number of studies with this GC-AES-polychromator system are presented. This system is capable of monitoring atomic emissions from C, H, F, Cl, Br, I, O, N and S all simultaneously, and the selectivity of this system is unsurpassed. Elemental ratios for separated compounds are also presented as a precursor to empirical formula prediction.

A Charge Injection Device (CID) detector has been evaluated as a detector for simultaneous multielement atomic emission spectroscopy. The CID was incorporated into a special liquid nitrogen cooled, computer controlled camera system. Electro-optical characterization of the CID and camera system included determination of readout noise, quantum efficiency, spatial crosstalk, temporal hysteresis, spatial response uniformity, and linear dynamic range. The CID was used as a spectroscopic detector for an echelle grating spectrometer equipped with a direct current plasma emission source. The spectrometer was a standard commercial instrument modified to provide a reduced image format more suitable for use with the CID detector. The optical characteristics of this spectrometer, including wavelength coverage, and optical aberrations are described. The spectroscopic system was evaluated with respect to detection limits, linear dynamic range, and accuracy in both single element and simultaneous multielement modes. Detection limits compared well to literature values reported for photomultiplier tube detector based systems under similar conditions. CID detection limits were superior in the near infrared and visible wavelength region, comparable in the middle UV, and higher in the far UV. The detection limits were determined to be limited by background radiation shot noise. Several elements of a certified standard reference material were simultaneously determined in order to assess the accuracy of the spectroscopic system. The results were highly accurate, even when operating near or below the 3σ limits of detection. Spectral interferences for elements were avoided by using several analytical lines for each element. The results of these investigations indicate that the CID is a superior multichannel detector for analytical atomic emission spectrometry. The capability to simultaneously monitor a wide, continuous spectral range with high spatial resolution, high dynamic range, low readout noise, and insignificant signal crosstalk is now possible. Many analytical benefits of this approach, such as the potential capability to perform rapid qualitative and semiquantitative analysis and the ability to select the optimum spectral lines for highly accurate quantitative analysis are now readily achievable.

Thesis (Ph. D.)--University of Washington, 1991. / Vita. Includes bibliographical references (leaves [131]-137).

The first part of the master thesis is focused on theoretical analysis of the problems of diagnostics of an electric arc physical properties. In the thesis there is shown identification of spectral lines in experimentally measured electric arc spectra. The thesis deals also with energy balance of the arc. Next part of thesis is aimed to theoretical analysis of effects of electric arc on construction materials of low voltage electric apparatuses. The main part of thesis is devoted to experimental measurement of arc radial temperature changes, measurement of cathode temperature and research of electrical arc effect on selected construction materials of low voltage apparatuses.

Atomic emission spectrometry (AES) with a plasma has proven to be an important method for the analysis of metallic and nonmetallic species in a variety of matrices. Not only is atomic spectrometry useful for accurate and sensitive quantitative analysis, but it can be used as a means of unambiguous qualitative determinations. The most common matrix for AES samples is liquid. Whether aqueous or organic in nature, the majority of samples are dissolved in some sort of solvent. Unfortunately, for most modes of sample introduction, a large portion of the solvent is simultaneously introduced to the plasma discharge along with the analyte species. The plasma is thus required not only to sufficiently excite the analyte, but also to desolvate and vaporize the solvent species. These processes tend to diminish the available energy of the plasma that is to be directed toward the analyte. The nature of the energy loss due to solvent loading is not well understood and is the topic of debate for different systems. It is the focus of this dissertation to determine the effect of solvent loading on the Highly Efficient Microwave Induced Plasma (HEMIP). The magnitude of solvent loading for Ar and He discharges using different sample introduction systems is determined. The solvent load is shown to have two separate constituents: aerosol and vapor. Each of these are shown to affect the plasma in different ways. Two different sample introduction systems are evaluated for their respective solvent loadings: a cooled pneumatic nebulizer / double pass spray chamber and an ultrasonic nebulization system. These systems are compared under their normal operating conditions and for the two plasma support gases. High solvent loads are shown to destabilize both the Ar and He microwave plasmas, decrease analytical sensitivity, and attenuate the energy of the plasma discharge. The conditions under which solvent loading is minimized do not have a significant effect on the operational characteristics of the sample introduction systems, but provide the optimal analytical sensitivity and limits of detection for the HEMIP. / Ph. D.

Requirements of high performing engine oil are today necessary since the development of new machinery with modern standardsis a cutting edge technology demanding highly optimized components. One way of increasing the lubricating properties of engineoil is through the addition of antioxidants. Antioxidants included in lubricants have a number of functions, one being buffering theinorganic acids sulphuric acid and nitric acid.A novel method expected to lower the hydrogen ion concentration in acidified engine oil was evaluated in this thesis. Thecapability of four different types of cation exchangers to serve as complements for buffering additives in heavy vehicle engineswas assessed. Two cation exchangers were weak and two were strong. The analysis techniques used to evaluate what effect thecation exchangers have on engine oil were standard test method ASTM D4739, for measurements of the total base number (TBN),and inductively coupled plasma – atomic emission spectroscopy (ICP-AES). With ASTM D4739 it was found that weak cationexchangers give positive results with respect to the ability to decrease the hydrogen ion concentration in acidified engine oil.However, after begin subjected to strong cation exchangers, ASTM D4739 indicated that the hydrogen ion concentration in theacidified engine oil remains the same or increases.With additional literature studies of a variety of cation exchangers currently on the market, further optimization of the cationexchanging material could likely be achieved. In addition, the preparation method used during the evaluation of the cationexchangers should be optimized to give more reliable results.

Graphite Furnace Atomic Absorption Spectroscopy (GFAA) and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) are two primary means of analyzing metals at the elemental level. Both techniques are widely accepted as tools for basic research. Each technique is performed differently and has its own distinct advantages as well as disadvantages. The choice of which technique to employ is determined by the needs of the analysis and the limitations of the instrumental technique.The idea to merge the two techniques was originallydeveloped by the research group of Dr. Michael W. Blades of the University of British Columbia, Vancouver, in 1989, who successfully demonstrated a "mini" plasma within a graphite furnace. The goal of the research was to design a device that would combine the advantages of both techniques and hopefully eliminate or minimize the unfavorable characteristics of each technique.The sustaining of a "mini" plasma has been demonstrated by this group. Although the end result was similar to that of Blades' group, the method of achieving the plasma was such that the "new" instrument could easily be mounted onto the furnace via a small Interface/Power Coupling device. The advantages of this system are: existing GFAA instruments can be used; modification of the furnace and RF supply is minimal; RF electronics can be remotely located; removal of the interface device is quickly achieved; and sample introduction, through the use of an autosampler, can be facilitated with small modification.Background spectra were acquired using helium, argon, and a mixture of argon/helium. It was found that all the plasmas have highly structured backgrounds and demonstrate the potential for many analysis regions. Two methods of sample introduction were used in acquiring the line emission of magnesium: injection through the sample inlet port to the furnace and end window injection. Inlet port injection suffers from a loss of sensitivity, when compared to end cap injection, but is more easily performed. / Department of Chemistry

Incineration is an attractive solution to the problems of disposing of municipal solid wastes and supplying energy. Because up to 25 percent of the waste in refuse-derived-fuel systems is ash, the physical and chemical characteristics of ash become more and more important for its potential impacts and methods suitable for their disposal. Trace elements concentration in ash is of great interest because of its relationship to regulatory criteria under the Resource Conservation and Recovery Act (RCRA) regarding toxicity and hazards. The applications of a microwave oven sample dissolution method has been tested on a variety of standard reference materials, with reproducible and accurate results. Fourteen trace elements, As, Ba, Be, Cd, Cr, Cu, Hg, Ni, Pb, Sb, Se, Tl, V, and Zn, from the dissolved ash samples were determined by inductively coupled plasma atomic emission spectrometry.

Thesis (Ph. D.)--Joint Program in Oceanography/Applied Ocean Science and Engineering (Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and the Woods Hole Oceanographic Institution), 2007. / Includes bibliographical references. / Present-day expeditionary oceanography is beginning to shift from a focus on short-term ship and submersible deployments to an ocean observatory mode where long-term temporally-focused studies are feasible. As a result, a critical need for in situ chemical sensors is evolving. New sensors take a significant amount of time to develop; thus, the evaluation of techniques in the laboratory for use in the ocean environment is becoming increasingly important. Laser-induced breakdown spectroscopy (LIBS) possesses many of the characteristics required for such in situ chemical sensing, and is a promising technique for field measurements in extreme environments. Although many LIBS researchers have focused their work on liquid jets or surfaces, little attention has been paid to bulk liquid analysis, and especially to the effect of oceanic pressures on LIBS signals. In this work, laboratory experiments validate the LIBS technique in a simulated deep ocean environment to pressures up to 2.76 x 10⁷ Pa. A key focus of this work is the validation that select elements important for understanding hydrothermal vent fluid chemistry (Na, Ca, Mn, Mg, K, and Li) are detectable using LIBS. A data processing scheme that accurately deals with the extreme nature of laser-induced plasma formation was developed that allows for statistically accurate comparisons of spectra. The use of both single and double pulse LIBS for high pressure bulk aqueous solutions is explored and the system parameters needed for the detection of the key analytes are optimized. Using both single and double pulse LIBS, the limits of detection were found to be higher than expected as a result of the spectrometer used in this experimentation. However, the results of this validation show that LIBS possesses the characteristics to be a viable chemical sensing method for in situ analyte detection in high pressure environments like the deep ocean. / by Anna Pauline Miranda Michel. / Ph.D.

Wegen der zunehmenden Menge an LIBS-Daten von der Marsoberfläche sowie deren speziellen Herausforderungen bei der Analyse untersucht diese Arbeit, wie die Modellierung und Simulation von solchen LIBS-Spektren genutzt werden kann. Das Ziel ist es, Einblicke in die Eigenschaften von LIBS-Plasmen auf dem Mars zu erhalten und Modelle zu entwickeln, die bei der Analyse von realen Missionsdaten helfen können. Die Modellierung basiert sich auf einem stationären Plasma im lokalen thermischen Gleichgewicht (LTE). Das Plasma wird dabei in eine Reihe homogener Zonen unterteilt und Spektren werden mit dem Strahlungstransfer entlang einer eindimensionalen Sichtlinie durch diese Plasmazonen simuliert. Die Ergebnisse dieser Arbeit zeigen, dass auf LTE basierende Modelle gut auf LIBS-Spektren angewendet werden können, die unter Marsbedingungen gemessen wurden. Für zeitaufgelöste Daten kann die Anpassung eines Zwei-Zonen-Modells verwendet werden, um Einblicke in das Plasma zu erhalten und um die Elementkonzentrationen mit einer höheren Genauigkeit zu bestimmen, als es mit der Saha-Boltzmann-Methode möglich wäre. Allerdings sollten Nicht-Gleichgewichtseffekte in den frühesten und spätesten Phasen der Plasmalebensdauer berücksichtigt werden. Für zeitlich integrierte Spektren, wie sie bei aktuellen Marsmissionen gemessen werden, sind Anpassungen durch ein Zwei-Zonen-Modell aufgrund von zu langen Rechenzeiten nicht durchführbar. Stattdessen kann durch die Methode der spektralen Entmischung eine Überlagerung von Spektren unterschiedlicher Temperaturen und Dichten verwendet werden. Diese Methode ermöglicht keine direkten quantitativen Bestimmungen der Elementkonzentrationen, ist aber ein hervorragendes Werkzeug, um einen Überblick über die große Menge an Informationen zu erhalten, die in den Spektren enthalten sind. / Motivated by existing challenges in analysing LIBS spectra and the increasing quantity of Martian LIBS data, this thesis investigates the modelling and simulation of LIBS spectra for the application to LIBS data in Martian atmospheric conditions. This is done with the aim of providing insights into the characteristics of Martian LIBS plasmas as well as developing tools to assist the analysis of real mission data. The modelling of LIBS spectra is based on a stationary plasma in local thermal equilibrium (LTE). The plasma is then divided into a series of homogeneous zones and spectra are simulated using radiative transfer along a one-dimensional line-of-sight through the plasma zones. The results of this thesis show that spectral modelling based on LTE can be well applied to LIBS data in Martian atmospheric conditions. For time-resolved data, fits of a two-zone plasma model can be used to obtain insights into the plasma as well as improved concentration estimates compared to the Saha-Boltzmann plot method. However, attention to non-equilibrium effects should be given at the earliest and latest stages of the plasma lifetime. For time-integrated spectra, i.e. real mission data, fits of the two-zone model are not feasible due to too long computation times. Instead, a superposition of spectra of different temperatures and densities, i.e. the spectral unmixing method, can be used. Although not directly allowing for quantitative concentration estimates, the method is a great tool to overview the large amount of information contained in the spectra.