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.

A espectrometria de emissão óptica com plasma induzido por laser (LIBS) tem se tornado uma técnica muito atrativa e bastante explorada nas análises químicas e tem ganhado destaque devido à disponibilidade de instrumentos portáteis, o qual possibilita a análise in situ. Por outro lado, a análise quantitativa tem sido considerada o \"calcanhar de Aquiles\" da técnica, face as suas dificuldades em executá-la, em especial devido à complexa interação laser-matriz. Nesse contexto, o uso de métodos de calibração apropriados é imperativo. Neste trabalho avaliou-se a possibilidade de empregar LIBS na identificação, discriminação e quantificação elementar em amostras de madeira, uma vez que essa matriz tem grande importância econômica e ambiental. O desenvolvimento de método envolveu a otimização dos parâmetros instrumentais (diâmetro de focalização de 50&#181;m, energia por pulso de 20 mJ, taxa de repetição de 10 Hz, tempo de atraso de 0,25&#181;s, padrão de análise percurso, 300 pulsos de laser, deslocamento da amostra de 0,15 mm/s e fluxo de argônio de 1,0 L/min), bem como a avaliação da influência da umidade, tamanho de partícula e homogeneidade nos resultados analíticos. Diversos métodos de calibração também foram estudados, entre eles, a calibração empregando diferentes CRMs que geraram resultados com erros relativos superiores a 30%. Calibração construída com madeira Pinus adicionada com concentrações crescentes de analito foi a que apresentou os melhores resultados (erros relativos< 20%). Outra abordagem envolveu a confecção de um branco analítico por meio da lavagem da madeira, seguida pela adição elementar o qual apresentou resultados com erros relativos de até 14%, mostrando-se bastante promissora. Apesar disso, aplicações em amostras in natura não é trivial devido à sua baixa homomogeneidade e especialmente devido ao fato de o analito naturalmente presente na amostra interagir de forma diferente ao analito artificialmente adicionado à matriz. A aplicação do LIBS na avaliação da distribuição elementar nos anéis de crescimento de árvores foi eficiente, assim como na discriminação e identificação de amostras de madeira que atingiu 100% de exatidão no índice de acerto quando aplicado KNN. / Laser-induced breakdown spectroscopy (LIBS) has become a very attractive and well-exploited technique in chemical analysis and has gained prominence due to the availability of portable instruments, which enables in situ analysis. On the other hand, quantitative analysis has been considered the \"Achilles heel\" of this technique, especially due to the strong matrix interference caused by complex laser-matrix interaction. In this context, the use of appropriate calibration methods is imperative.In this work the possibility of using LIBS in the identification, discrimination, and elemental quantification in wood samples was evaluated, since this matrix has an economic and an environmental importance. The method development involved the optimization of the instrumental parameters (50 &#181;m of spot size, 20 mJ of energy by pulse, 10 Hz of pulse repetition rate, 0.25 &#181;s of delay time, raster, 300 laser pulses, sample velocity of 0.15 mm/s and argon flow of 1.0 L/min), as well as the influence of moisture, particle size and homogeneity onto the analytical results. Several calibration methods were also studied, among them, the calibration using different CRMs which was not a good purpose since relative errors higher than 30% on the results were found. The calibration made with Pinus wood spiked with increasing concentrations of analytes showed the best results (relative errors <20%) for wood analysis. Another approach involved the preparation of an analytical blank by washing wood samples with 0.1% HNO3, followed by spiking of increasing concentration of analytes. In this case, relative errors of up to 14% were found, suggesting it is a promising approach. Despite this, applications of these proposed methods in quantitative analysis of in natura wood samples are not trivial due to their low homomogeneity and especially due to the differences on interaction between laser and naturally occurring analyte and artificially spiked analyte. The application of LIBS in the evaluation of the elemental distribution in the tree growth rings was efficient, as well as in the discrimination and identification of wood samples since 100% accuracy were reached when KNN was applied.

Chan Sze-Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 65-73). / Abstracts in English and Chinese. / Acknowledgment --- p.i / Table of Contents --- p.ii / Abstract --- p.v / Abstract (Chinese Version) --- p.vi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Molybdenum in the Environment --- p.1 / Chapter 1.1.1 --- General Chemistry of Molybdenum --- p.1 / Chapter 1.1.2 --- Molybdenum in Animals and Plants --- p.1 / Chapter 1.1.3 --- Uses of Molybdenum Compounds --- p.3 / Chapter 1.2 --- Inductively Coupled Plasma Atomic Emission Spectrometry --- p.4 / Chapter 1.2.1 --- Principle of ICP-AES --- p.4 / Chapter 1.2.2 --- Inductively Coupled Plasma Emission Source --- p.5 / Chapter 1.2.3 --- Optical System --- p.6 / Chapter 1.2.4 --- Advantages of ICP-AES --- p.7 / Chapter 1.2.5 --- Disadvantages of ICP-AES --- p.8 / Chapter 1.3 --- Preconcentration Method --- p.9 / Chapter 1.4 --- Polysiloxane --- p.11 / Chapter 1.4.1 --- Introduction of Silica-gel --- p.11 / Chapter 1.4.2 --- Introduction of Sol-gel Processes --- p.13 / Chapter 1.4.3 --- Hybrid Inorganic-organic Sol-gel Materials --- p.14 / Chapter 1.4.4 --- Advantages Using Sol-gel Preparation of Organomodified Silica --- p.16 / Chapter 1.5 --- Chelating Resin --- p.19 / Chapter 1.6 --- Scope of Work --- p.21 / Chapter Chapter 2 --- Experimental --- p.22 / Chapter 2.1 --- Apparatus and Instrument --- p.22 / Chapter 2.2 --- Chemicals --- p.24 / Chapter 2.3 --- Samples --- p.25 / Chapter 2.4 --- Procedures --- p.26 / Chapter 2.4.1 --- Preparation of Diethylenetriaminetetraacetic-acid Functionalized Polysiloxane --- p.26 / Chapter 2.4.1.1 --- Preparation of Silica Precursor --- p.26 / Chapter 2.4.1.2 --- Functionalization with Diethylenetriamine --- p.27 / Chapter 2.4.1.3 --- Carboxymethylation of the amine groups of the Polysiloxane --- p.28 / Chapter 2.4.2 --- Preconcentration and Determination of Molybdenum --- p.29 / Chapter 2.4.2.1 --- Optimum pH for Adsorption --- p.29 / Chapter 2.4.2.2 --- Amount of Polysiloxane Required for Sorption of Trace Amount of Molybdenum --- p.29 / Chapter 2.4.2.3 --- Equilibrium Time --- p.30 / Chapter 2.4.2.4 --- Total Adsorption Capacity --- p.30 / Chapter 2.4.2.5 --- Adsorption Isotherm of Molybdenum --- p.30 / Chapter 2.4.2.6 --- Desorption Studies --- p.31 / Chapter 2.4.2.7 --- Effect of Foreign Ions on Preconcentration --- p.31 / Chapter 2.4.2.8 --- Preparation of the Mini-column --- p.32 / Chapter 2.4.2.9 --- Effect of Flow Rate --- p.33 / Chapter 2.4.2.10 --- Reusability of the Mini-column --- p.33 / Chapter 2.4.2.11 --- Preconcentration Factor and Detection Limit --- p.33 / Chapter 2.4.2.12 --- Determination of Mo(VI) in Seawater by ICP-AES --- p.33 / Chapter Chapter 3 --- Results and Discussion --- p.35 / Chapter 3.1 --- Characterization of Diethylenetriaminetetraacetic-acid Functionalized Polysiloxane --- p.35 / Chapter 3.2 --- pH Dependence of Mo(VI) Ion Uptake --- p.44 / Chapter 3.3 --- Amount of Polysiloxane Required for Adsorption of Trace Amount of Mo(VI) --- p.45 / Chapter 3.4 --- Equilibrium Time --- p.46 / Chapter 3.5 --- Total Adsorption Capacity --- p.47 / Chapter 3.6 --- Adsorption Isotherm of Molybdenum --- p.48 / Chapter 3.7 --- Desorption Studies --- p.54 / Chapter 3.8 --- Effect of Foreign Ions on Preconcentration --- p.55 / Chapter 3.9 --- Effect of Flow Rate on the Recovery of Mo(VI) --- p.57 / Chapter 3.10 --- Reusability of the Column --- p.58 / Chapter 3.11 --- Preconcentration Factor --- p.59 / Chapter 3.12 --- Detection Limit --- p.59 / Chapter 3.13 --- Accuracy --- p.60 / Chapter 3.14 --- Determination of Mo(VI) in Seawater Samples --- p.61 / Chapter 3.15 --- Precision --- p.62 / Chapter Chapter 4 --- Conclusion --- p.63 / Chapter Chapter 5 --- References --- p.65

A espectrometria de emissão óptica com plasma induzido por laser (LIBS) tem se tornado uma técnica muito atrativa e bastante explorada nas análises químicas e tem ganhado destaque devido à disponibilidade de instrumentos portáteis, o qual possibilita a análise in situ. Por outro lado, a análise quantitativa tem sido considerada o \"calcanhar de Aquiles\" da técnica, face as suas dificuldades em executá-la, em especial devido à complexa interação laser-matriz. Nesse contexto, o uso de métodos de calibração apropriados é imperativo. Neste trabalho avaliou-se a possibilidade de empregar LIBS na identificação, discriminação e quantificação elementar em amostras de madeira, uma vez que essa matriz tem grande importância econômica e ambiental. O desenvolvimento de método envolveu a otimização dos parâmetros instrumentais (diâmetro de focalização de 50&#181;m, energia por pulso de 20 mJ, taxa de repetição de 10 Hz, tempo de atraso de 0,25&#181;s, padrão de análise percurso, 300 pulsos de laser, deslocamento da amostra de 0,15 mm/s e fluxo de argônio de 1,0 L/min), bem como a avaliação da influência da umidade, tamanho de partícula e homogeneidade nos resultados analíticos. Diversos métodos de calibração também foram estudados, entre eles, a calibração empregando diferentes CRMs que geraram resultados com erros relativos superiores a 30%. Calibração construída com madeira Pinus adicionada com concentrações crescentes de analito foi a que apresentou os melhores resultados (erros relativos< 20%). Outra abordagem envolveu a confecção de um branco analítico por meio da lavagem da madeira, seguida pela adição elementar o qual apresentou resultados com erros relativos de até 14%, mostrando-se bastante promissora. Apesar disso, aplicações em amostras in natura não é trivial devido à sua baixa homomogeneidade e especialmente devido ao fato de o analito naturalmente presente na amostra interagir de forma diferente ao analito artificialmente adicionado à matriz. A aplicação do LIBS na avaliação da distribuição elementar nos anéis de crescimento de árvores foi eficiente, assim como na discriminação e identificação de amostras de madeira que atingiu 100% de exatidão no índice de acerto quando aplicado KNN. / Laser-induced breakdown spectroscopy (LIBS) has become a very attractive and well-exploited technique in chemical analysis and has gained prominence due to the availability of portable instruments, which enables in situ analysis. On the other hand, quantitative analysis has been considered the \"Achilles heel\" of this technique, especially due to the strong matrix interference caused by complex laser-matrix interaction. In this context, the use of appropriate calibration methods is imperative.In this work the possibility of using LIBS in the identification, discrimination, and elemental quantification in wood samples was evaluated, since this matrix has an economic and an environmental importance. The method development involved the optimization of the instrumental parameters (50 &#181;m of spot size, 20 mJ of energy by pulse, 10 Hz of pulse repetition rate, 0.25 &#181;s of delay time, raster, 300 laser pulses, sample velocity of 0.15 mm/s and argon flow of 1.0 L/min), as well as the influence of moisture, particle size and homogeneity onto the analytical results. Several calibration methods were also studied, among them, the calibration using different CRMs which was not a good purpose since relative errors higher than 30% on the results were found. The calibration made with Pinus wood spiked with increasing concentrations of analytes showed the best results (relative errors <20%) for wood analysis. Another approach involved the preparation of an analytical blank by washing wood samples with 0.1% HNO3, followed by spiking of increasing concentration of analytes. In this case, relative errors of up to 14% were found, suggesting it is a promising approach. Despite this, applications of these proposed methods in quantitative analysis of in natura wood samples are not trivial due to their low homomogeneity and especially due to the differences on interaction between laser and naturally occurring analyte and artificially spiked analyte. The application of LIBS in the evaluation of the elemental distribution in the tree growth rings was efficient, as well as in the discrimination and identification of wood samples since 100% accuracy were reached when KNN was applied.

Thesis (M.S.)--Brigham Young University. Dept. of Chemistry and Biochemistry, 2004. / Includes bibliographical references.

The application of inductively coupled plasma time-of-flight mass spectrometers (ICP-TOFMS) coupled to electrothermal vaporization (ETV) presents several unique analytical opportunities for isotopic analysis. This dissertation explores several subjects that utilize these characteristics in specific analytical applications. The viability of using the thermal programming abilities of the ETV in order to separate Rb and Sr is explored. These elements are isobaric at m/z 87, and must normally be separated prior to analysis for isotopic studies. Their disparate thermal properties allow them to be separated in time by the ETV allowing for simpler, faster isotope ratio analysis with less opportunity for contamination. A test case using standard potassium feldspar is found to produce moderately accurate and precise results. TOF instruments are of interest for isotope ratio analysis due to inherent isotope ratio precision. However, it has been observed that when operated in the analog data collection mode the isotope ratios observed possess a previously uncharacterized inaccuracy. This bias is rooted in variable detection efficiency of arriving ions, which can be corrected for with an algorithm described within. A method of determining the effective detector efficiency as a function of signal is presented, as well as an evaluation of the effectiveness of ratio correction. The use of ETV with TOF for isotope dilution analysis is explored. Correction of transient signals for efficiency effects is discussed, as well as the viability of using the autosampler for mixing of the solution and spike. A final study presents explores the combination of the ETV and TOF for analysis of a large number of elements from a brief transient signal. A library of peptide covered beads is analyzed for binding capacity to a variety of metals. Solutions containing metals stripped from the beads are analyzed to determine the binding capacity and specificity of the peptide sequence. The beads themselves are also analyzed for metal content using the ETV as an indicator of the efficiency of metal stripping off of the beads. / text

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

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

Thesis (M.Sc.) - Carleton University, 2006. / Includes bibliographical references (p. 85-86). Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.