J.A.C. Broekaert

Glow discharge plasmas in analytical spectroscopy

Preface. List of Contributors. Introduction (R. K. Marcus and J. A. C. Broekaert). Optical Emission Spectrometry with Glow Discharges (J. A. C. Broekaert). Mass Spectrometry of Glow Discharges (W. W. Harrison, C. Yang and E. Oxley). Radio Frequency Glow Dicharges (R. K. Marcus). Depth Profile Analysis (A. Bengston). Numerical Modeling of Analytical Glow Discharges (A. Bogaerts and R. Gijbels). Application of Glow Discharge Optical Emission Spectrometry in the Steel Industry (K. Kakita). Surfaces, Thin Films and Coatings (R. Payling, et al.). Comparison of Glow Discharge Atomic Spectrometry to Other Surface Analysis Methods (K. Wagatsuma). Analysis of Samples of Nuclear Concern with Glow Discharge Atomic Spectrometry (M. Betti). Analysis of Nonconducting Materials by dc Glow Discharge Spectrometry (A. Bogaerts, et al.). Standards and Reference Materials for Glow Discharge Spectroscopies (M. Winchester). Analysis of Liquid Samples Using Glow Discharge Spectroscopies (R. K. Marcus). GC Speciation with GDMS Detect ion (J. A. Caruso and L. Milstien). Glow Discharge Atomic Emission Spectrometry for the Analysis of Gases and as an Alternative Gas Chromatographic Detector (R. Pereiro, et al.). Low pressure Inductively Coupled Plasmas (H. Evans). Multidimensional Ionization Sources for Plasma source Mass Spectrometry (J. P. Guzowski and G. M. Hieftje). Index.

Analytical atomic spectrometry with flames and plasmas

Preface.Introduction.1. BASIC PRINCIPLES Atomic structure Plasmas Emission and absorption of radiation Ionization Dissociation Sources for atomic spectrometry Analytical atomic spectrometry 2. SPECTROMETRIC INSTRUMENTATION Figures of merit of an analytical method Optical spectrometers Mass spectrometers Data acquisition and treatment SAMPLE INTRODUCTION DEVICES Pneumatic nebulization Ultrasonic nebulization Hydride generation Eletrothermal evaporation Direct solids sampling Cathodic sputtering 4. ATOMIC ABSORPTION SPECTROMETRY Principles Atomic absorption spectrometers Flame atomic absorption Electrothermal atomic absorption Hydride generation Background correction techniques Fields of application 5. ATOMIC EMISSION SPECTROMETRY Principles Atomic emission spectrometers Flame emission Arcs and sparks Plasma sources Glow discharges Laser sources Fields of application 6. PLASMA MASS SPECTROMETRY Principles Instrumentation Glow discharge mass spectrometry ICP mass spectrometry Fields of application 7. ATOMIC FLUORESCENCE SPECTROMETRY Principles Figures of merit 8. LASER ENHANCED IONIZATION SPECTROMETRY Principles Figues of merit Analytical Applications.9. SAMPLE PREPARATION FOR ATOMIC SPECTROMETRY Sample Preparation in direct compact sample analysis.Grinding, sieving and compaction of powders.Sample dissolution.Wet chemical methods.Fusion Procedures.Microwave-assisted methods.Combustion Techniques.Flow injection analysis.Leaching sample preparation methods 10. COMPARISON WITH OTHER METHODS Power of detection Analytical accuracy Economic aspects.Literature.Index

A new low-power microwave plasma source using microstrip technology for atomic emission spectrometry

A new low-power, compact microwave-induced plasma source for applications in atomic emission spectrometry at atmospheric pressure using microstrip technology is described. The gas channel of about 1 mm2 is integrated in a fused silica dielectric wafer. The microstrip transmission lines are fabricated by sputtering and electro-plating. For example, a unit operates at an input power of 15 W with an argon gas flow of about 500 ml min-1 at atmospheric pressure. Rotational (OH) and excitation (Fe) temperatures of 650 K and 8000 K, respectively, were measured at these conditions. The emitted radiation can be taken up by an optical fibre positioned in the plasma-gas channel thus enabling an axial observation and coupling to a miniaturized spectrometer. The first devices showed an operation time of at least several hundred hours. Further investigations will lead to even smaller dimensions and lower power consumption and open the way for integrated microwave plasma sources with low detection limits as integrable parts of miniaturized total analytical systems applications.

ZT enhancement in solution-grown Sb(2-x)BixTe3 nanoplatelets.

We report a solution-processed, ligand-supported synthesis of 15-20 nm thick Sb(2-x)BixTe3 nanoplatelets. After complete ligand removal by a facile NH3-based etching procedure, the platelets are spark plasma sintered to a p-type nanostructured bulk material with preserved crystal grain sizes. Due to this nanostructure, the total thermal conductivity is reduced by 60% in combination with a reduction in electric conductivity of as low as 20% as compared to the bulk material demonstrating the feasibility of the phonon-glass electron-crystal concept. An enhancement in the dimensionless thermoelectric figure of merit of up to 15% over state-of-the-art bulk materials is achieved, meanwhile, shifting the maximum to significantly higher temperatures.

Degradation of short-chain alkyl- and alkanolamines by TiO2- and Pt/TiO2-assisted photocatalysis.

The photooxidation of C2H5NH2, (C2H5)2NH, HOC2H4NH2, (HOC2H4)2NH and (HOC2H4)3N using TiO2 and Pt/TiO2 as photocatalysts has been investigated. A laboratory set up was designed and a study on the influence of the concentration of the photocatalyst, the pH-value and the structure of the amine performed. The photocatalytic process was optimized with respect to the concentrations of the model substances during degradation. The decrease of the amine concentrations was found to be maximum at a pH of 10. The time-dependence of the formation of cationic breakdown products, such as NH3/NH4 and short-chain alkyl- and alkanolamines was studied by analyses with single column ion chromatography. The experimental data show that the photodegradation follows a Langmuir-Hinshelwood kinetic. The mineralization of the model substances also was monitored by measurements of the decrease of the TOC and of the formation of NO2 and NO3. The different mineralization efficiencies for the model substances studied are discussed with regard to their structure and adsorption behaviour on the photocatalyst. A possible breakdown mechanism involving the electrophilic attack of the hydroxyl radical is given. The applicability of the TiO2-assisted photocatalytic degradation of C2H5NH2 and (C2H5)2NH was tested at the pilot plant-scale with real solar radiation. The degradation rates and products obtained were similar to those found in the laboratory experiments.

Speciation of Chromium by Direct Coupling of Ion Exchange Chromatography With Inductively Coupled Plasma Mass Spectrometry

Ion exchange chromatography has been coupled with inductively coupled plasma mass spectrometry (ICP-MS) for the element speciation of chromium. Hydraulic high pressure nebulization was used for sample introduction with high aerosol efficiency. It was the particular aim of this work to exclusively use nitric acid for elution in order to reduce interferences in ICP-MS. Therefore, an anion exchange pre-column IonPac-AG5 (Dionex, Idstein, Germany) with a length of 50 mm and an id of 4 mm has been operated as a mixed-mode column, which shows cation exchange capabilities too. The column was operated at a flow rate of 1.2 ml min–1 and samples were injected by use of a sample loop with a volume of 100 µl. Both CrVI anions and CrIII cations could be retained on the column, and optimum results concerning chromatographic and mass spectrometric conditions were finally achieved with discontinuous elution in two steps by injection of 0.3 m (pH 0.5) HNO3 for CrVI and subsequently of 1.0 m (pH 0) HNO3 for CrIII. Detection limits just above 0.1 µg l–1 could be realized.

Speciation of chromium using reversed phase-high performance liquid chromatography coupled to different spectrometric detection methods

Speciation of Cr(III) and Cr(VI) based on the formation of different complexes with ammonium-pyrrolidinedithioate (APDC) in a continuous flow technique and their preconcentration using solid phase extraction (SPE) have been elaborated and applied to the analysis of waste waters from the galvanic industry. The Cr complexes were separated and determined using reversed phase-high performance liquid chromatography (RP-HPLC) coupled to different detection methods, namely UV-detection, graphite furnace-atomic absorption spectrometry (GF-AAS) and inductively coupled plasma mass spectrometry with hydraulic high pressure nebulization (HHPN/ICP-MS). After optimization the detection limits for Cr(III) and Cr(VI) of all methods are at the μg 1−1 level and the precision in terms of RSD is 5% (cCr = 100 μg 1−1, N = 10). The procedure was applied to the determination of Cr(III) and Cr(VI) at the μg 1−1 level in galvanic waste waters, and its accuracy was approved by comparing the results with those of independent methods.

Atomic Spectroscopy: A Review

Atomic Absorption Spectrometry 4653 Flame Atomic Absorption Spectrometry 4653 Electrothermal Atomic Absorption Spectrometry 4654 Volatile Species Generation Atomic Absorption Spectrometry 4654 Direct Solids Atomic Absorption Spectrometry 4655 Continuum Source Atomic Absorption Spectrometry 4655 Atomic Fluorescence Spectrometry 4655 Atomic Emission Spectrometry 4656 DC Arc and Low-Power RF Radiation Sources 4656 Inductively Coupled Plasmas 4656 Microwave Induced Plasmas 4658 Microplasmas 4658 Laser Induced Breakdown Spectroscopy 4658 Glow Discharge Optical Emission and Mass Spectrometry 4660 Fundamental Studies 4660 Methodological Studies and Applications of GD-OES and GDMS 4661 New GD Sources for Novel Applications and Combined GD-LA Systems 4663 Inductively Coupled Plasma Mass Spectrometry 4664 Fundamental Studies 4665 Instrumental Developments and Applications 4667 Literature Cited 4677

Degradation of nitrogen containing organic compounds by combined photocatalysis and ozonation.

The combination of TiO2-assisted photocatalysis and ozonation in the degradation of nitrogen-containing substrates such as alkylamines, alkanolamines, heterocyclic and aromatic N-compounds has been investigated. A laboratory set-up was designed and the influence of the structure of the N-compound, the TiO2 and ozone concentration on the formation of breakdown products were examined. The experimental results showed that a considerable increase in the degradation efficiency of the N-compounds is obtained by a combination of photocatalysis and ozonation as compared to either ozonation or photocatalysis only. The mineralization of the model substances was monitored by measurements of the TOC and ion-chromatographic determinations of the formed NO2- and NO3-. The temporal changes of concentrations of breakdown products, such as NH4+, short chain alkyl- and alkanolamines were determined by single column ion chromatography (SCIC) and as well as by electrospray mass spectrometry (EI-MS).

Different sample introduction systems for the multaneous determination of As, Sb and Se by microwave-induced plasma atomic emission spectrometry

Abstract The determination of hydride-forming elements using different sample introduction procedure into microwave-induced plasmas (MIPs) has been studied. For the determination of As, Sb and Se analyte introduction was accomplished with a pneumatic concentric glass nebulizer,a graphite furnace, or with thydride generation followed by cold-trapping or hot-trapping in a graphite furnace. The detection limits obtained with different types of low power MIPs (toroidal, 1 or 3 filament MIPs) operated in a TM 010 cavity according to Beenakker also were investigated. The contruction of the flow system used for preconcentration and the effects of reagent concentration, gas flow rates as with MIP-atomic emission spectrometry (AES) were investigated. The trapping of the hydrides followed by their vaporization showed substantial advantages over the other introduction systems investigated, especially with respect to power of detection. Further, mutual interferences being a big problem in atomic absorption spectrometry are widely absent in MIP-AES. Under compromise operating conditions the detection limits for As, Sb and Se are 0.4; 0.35; 0.25 ng ml −1 respectively, while the sample volume can be varied from 0.05 ml up to several millilitres.