“Comparison of 3 dry deposition models applied to field-measurements in the Southern Bight of the North-Sea”. Rojas CM, Van Grieken RE, Laane RW, Atmospheric environment 27, 363 (1993). http://doi.org/10.1016/0960-1686(93)90110-K
Abstract: Dry deposition velocities have been calculated using three different approaches. Turbulent wind profile theory has been used to predict the drag coefficient, wind speed and friction velocity at 10 m height when the wind speed is measured at a higher altitude. The resulting parameters were introduced in a two-layer deposition model. The second approach was the well-known model of Slinn and Slinn (1980, Atmospheric Environment 14, 1013-1016), whereas the third corresponded to the model published by Williams (1982, Atmospheric Environment 16, 1933 1938). Results point to clear differences. However, in a field experiment carried out at the Southern Bight of the North Sea, all three approaches show relatively comparable results. The role played by the size distribution of atmospheric particulate matter is essential. In our case any of the three models could have given satisfactory outcomes taking into account the wide spread of the experimental results cited in the literature for the same airshed.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0960-1686(93)90110-K
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“An overview of wet deposition of micropollutants to the North Sea”. Struyf H, Van Grieken R, Atmospheric environment: part A : general topics 27, 2669 (1993). http://doi.org/10.1016/0960-1686(93)90036-X
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0960-1686(93)90036-X
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“Electron microprobe characterization of individual aerosol particles collected by aircraft above the Southern Bight of the North Sea”. Rojas CM, Van Grieken RE, Atmospheric environment : an international journal 26a, 1231 (1992). http://doi.org/10.1016/0960-1686(92)90384-W
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0960-1686(92)90384-W
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“Atmospheric concentrations and size distributions of aircraft-sampled Cd, Cu, Pb and Zn over the Southern Bight of the North Sea”. Injuk J, Otten P, Laane R, Maenhaut W, Van Grieken R, Atmospheric environment : an international journal 26a, 2499 (1992). http://doi.org/10.1016/0960-1686(92)90102-Q
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0960-1686(92)90102-Q
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“Analytical study of the deterioration of sandstone, marble and granite”. Sweevers H, Van Grieken R, Atmospheric environment : an international journal 26b, 159 (1992). http://doi.org/10.1016/0957-1272(92)90019-O
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0957-1272(92)90019-O
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“Aerosols in Santiago de Chile : a study using receptor modeling with X-ray fluorescence and single particle analysis”. Rojas CM, Artaxo P, Van Grieken R, Atmospheric environment: part B : urban atmosphere 24, 227 (1990). http://doi.org/10.1016/0957-1272(90)90028-S
Abstract: Between 15 January and 26 February 1987, 51 fine and coarse mode aerosol samples were collected at the Universidad de Santiago de Chile Planetarium using a dichotomous sampler. The samples were analyzed by X-ray fluorescence for up to 17 elements (Mg, Al, Si, P, S, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br and Pb). Aerosol particles were individually studied by Electron Probe Microanalysis (EPMA) and Laser Microprobe Mass Analysis (LAMMA). The data set consisting of aerosol elemental concentrations and meteorological variables was subjected to Principal Factor Analysis (PFA), allowing the identification of six fine mode particle source classes (soil, industrial, sulfate particles, traffic, residual oil, wood-burnings), and five coarse mode particle source classes (soil, industrial, traffic, residual oil, sulfate particles). Both PFA solutions explained about 81 and 90% of the total variance in the data set, respectively. The regression of elemental mass concentrations on the Absolute Principal Factor Scores allowed the estimation of the contribution of the different source classes to the Santiago aerosol. Within the fine fraction, secondary SO42− particles were responsible for about 49% of the fine mode aerosol mass concentration, while 26, 13, 6.4 and 5.6% were attributed to wood-burning/car exhausts, residual oil combustion, soil dust/metallurgical, and soil dust/wood-burning releases, respectively. The coarse fraction source apportionment was mainly dominated by soil dust, accounting for 74% of the coarse mode aerosol mass concentration. A composite of soil dust and industrial release accounted for 13%; a composite of secondary sulfates contributed with 9%; a composite of soil dust and automotive emissions, and secondary sulfates were responsible for 4 and 0.03% of the coarse aerosol mass concentration, respectively. EPMA results are in satisfactory agreement with those from the bulk analysis and allowed the identification of eight particle types in both fine and coarse mode aerosols, pertaining to different source classes, namely soil, seaspray, secondary SO42−, metallurgical emissions and biomass burning release. EPMA also evidenced that one of the most abundant particle types corresponded to marine aerosol, having an average diameter of 0.7 μm for the fine mode and 2.2 μm for the coarse mode aerosol. LAMMA results indicate that, in fact, seaspray has been transported into the city of Santiago de Chile airshed, suffering several transformations and a sulfur enrichment. This analytical technique also provided evidence of the abundance of carbon-rich particles, which were not detected by either the bulk X-ray analysis or EPMA; they are probably due to fossil-fuel combustion releases.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0957-1272(90)90028-S
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“Electron microscopy study of the formation of Ni5Al3 in a Ni62.5Al37.5 B2 alloy: 2: plate crystallography”. Schryvers D, Ma Y, Toth L, Tanner LE, Acta metallurgica et materialia 43, 4057 (1995). http://doi.org/10.1016/0956-7151(95)00102-2
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 11
DOI: 10.1016/0956-7151(95)00102-2
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“Electron microscopy study of the formation of Ni5Al3 in a Ni62.5Al37.5 B2 alloy: 1: precipitation and growth”. Schryvers D, Ma Y, Toth L, Tanner LE, Acta metallurgica et materialia 43, 4045 (1995). http://doi.org/10.1016/0956-7151(95)00101-Z
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT)
Times cited: 27
DOI: 10.1016/0956-7151(95)00101-Z
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“Synthesis and characterization of tin dioxide powders for the realization of thick-film gas sensors”. Honoré, M, Lenaerts S, Desmet J, Huyberechts G, Roggen J, Sensors and actuators : B : chemical 19, 621 (1994). http://doi.org/10.1016/0925-4005(93)01224-R
Abstract: Semiconductor gas sensors produced with screen-printing techniques and based on home-made tin dioxide inks are presented. The ink consists of home-made tin dioxide powder added to a polymer solution to make it screen printable on 96% alumina substrates. The major work is performed on the preparation and the characterization of pure undoped tin dioxide powder produced by two different synthetic pathways. Inks prepared with powders from each method are consecutively handled in an identical way to obtain gas sensors. The sensor response towards different gases is measured and compared for both types of starting materials.
Keywords: A1 Journal article
DOI: 10.1016/0925-4005(93)01224-R
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“In situ infrared and electrical characterization of tin dioxide gas sensors in nitrogen/oxygen mixtures at temperatures up to 720 K”. Lenaerts S, Honoré, M, Huyberechts G, Roggen J, Maes G, Sensors and actuators : B : chemical 19, 478 (1994). http://doi.org/10.1016/0925-4005(93)01048-9
Abstract: FT-IR spectroscopy and impedance measurements of tin dioxide sensor materials at working temperatures up to 450 °C in atmospheres with varying O2/N2 ratio are used as an in situ probe to study the interactions at the surface of the semiconducting oxide. Every diminution in the oxygen content above the sample induces a broad IR absorption band (X-band) between 2300700 cm−1 with a few small peaks in the 1400850 cm−1 region of the spectrum superimposed on it. The X-band results from the enchanced electron concentration in the bulk of the tin dioxide domain. The fine structure is due to the absorption of several kinds of surface oxygen species associated vibration modes. The porous tin dioxide consists of domains were the outward shell is depleted of electrons by the formation of adsorbed O− species on oxygen surface sites, SO(O− species. In our proposed model for the impedance data this gives rise to a parallel RpCp circuit for the domain boundary characteristics and to an Rs parameter for the intradomain resistance. The evolution of these IR and impedance spectroscopic effects with temperature and oxygen content is used to set up, to confirm and refine a physicochemical operation model of tin dioxide gas sensor. This model consists of a sensitizing reaction sequence in the presence of oxygen and a gas-detection reaction sequence when a reducing gas is present. Based on this model, the principal disadvantages of this type of gas sensor become clear. Every factor that influences the concentration of SO(O−) species, causes a conductance modification. If we can control and direct the nature, the number and the arrangement of the tin dioxide domains, a directed development and improvement of the sensor characteristics is possible.
Keywords: A1 Journal article
DOI: 10.1016/0925-4005(93)01048-9
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“Non-linear mapping of microbeam proton-induced X-ray emission data for source identification of North Sea aerosols”. Treiger B, Injuk J, Bondarenko I, van Espen P, Van Grieken R, Breitenbach L, Wätjen U, Spectrochimica acta: part B : atomic spectroscopy 49, 345 (1994). http://doi.org/10.1016/0584-8547(94)80029-4
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)
DOI: 10.1016/0584-8547(94)80029-4
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“A general Monte-Carlo simulation of energy-dispersive X-ray fluorescence spectrometers : 1 : unpolarized radiation, homogenious samples”. Vincze L, Janssens K, Adams F, Spectrochimica acta: part B : atomic spectroscopy 48, 553 (1993). http://doi.org/10.1016/0584-8547(93)80060-8
Abstract: A general Monte Carlo program for the simulation of X-ray fluorescence (XRF) spectrometers is presented. The global layout of the program is discussed and the way in which variance reduction techniques have been employed to improve the efficiency of the code is described. For the case of polychromatic excitation in a direct excitation energy-dispersive (ED) XRF instrument, experimentally collected ED-XRF spectra are compared with simulated spectral distributions. Applications of the software in the field of quantitative analysis and thickness estimation of samples of intermediate thickness illustrate the potential of the method.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0584-8547(93)80060-8
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“Molecular ion distributions in laser microprobe mass-spectrometry of calcium-oxide and calcium salts”. Bruynseels FJ, Van Grieken RE, Spectrochimica acta: part B : atomic spectroscopy 38, 853 (1983). http://doi.org/10.1016/0584-8547(83)80184-0
Abstract: Laser Microprobe Mass Spectrometry (LAMMA) is used to examine micrometric particles of calcium oxyanion salts (CaCO3, CaSO4, CaSO4·2H2O) and calcium oxide, in both the positive and negative ion mode. The major molecular ions, appearing in the positive mass spectrum, can be divided into three series, namely CamOm-1+, (CaO)m+ and (CaO)mH+ (m = 1-4). In the case of the former two series the relative intensities of the mass peaks as a function of the fragment valence K = (1 + 2n)/m, for CamOn+, can be fitted to a Gaussian distribution curve, as was earlier demonstrated for secondary ion mass spectrometry. The high stability of the (CaO)mH+ series can be explained by the favourable fragment valence of +2 corresponding to the usual oxidation state of calcium.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0584-8547(83)80184-0
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“FT-IR characterization of tin dioxide gas sensor materials under working conditions”. Lenaerts S, Roggen J, Maes G, Spectrochimica acta: part A: molecular and biomolecular spectroscopy 51, 883 (1995). http://doi.org/10.1016/0584-8539(94)01216-4
Abstract: In this work self-supporting tin dioxide disks are characterized using FT-IR spectroscopy in the presence of a reducing gas in air, and in different O2/N2 mixtures at temperatures varying from room temperature up to 450°C. Every factor inducing a change in the oxygen content of the gas atmosphere above the tin dioxide, as for instance a temperature change, a surface reaction or adsorption of another species, induces a broad, intense IR absorption band with discrete weak bands superimposed on it. This broad absorption is assigned to the electronic transition from a native donor level, the oxygen vacancy in the bulk of the domain, to the conduction band of the tin dioxide material. For the interpretation of the narrow, superimposed absorptions, two hypotheses remain. The results demonstrate that FT-IR spectroscopy is an extremely suitable technique for the characterization of semiconducting metal oxide sensors, since it allows to follow in situ the processes in the bulk, at the surface and in the surrounding gas atmosphere of the sensor material at working temperature as well as in the presence of reducing gases in air.
Keywords: A1 Journal article
DOI: 10.1016/0584-8539(94)01216-4
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“Determination of protein-bound copper and zinc in some organs of the cuttlefish Sepia officinalis L”. Decleir W, Vlaeminck A, Geladi P, Van Grieken R, Comparative biochemistry and physiology : B : biochemistry and molecular biology 60, 347 (1978). http://doi.org/10.1016/0305-0491(78)90057-3
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0305-0491(78)90057-3
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“Geochemical characterization of recent sediments in the Baltic Sea by bulk and electron microprobe analysis”. Belmans F, Van Grieken R, Brügmann L, Marine chemistry 42, 223 (1993). http://doi.org/10.1016/0304-4203(93)90014-F
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0304-4203(93)90014-F
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“Geochemistry of suspended matter from the Baltic Sea: 2: results of bulk trace metal analysis by AAS”. Brügmann L, Bernard PC, Van Grieken R, Marine chemistry 38, 303 (1992). http://doi.org/10.1016/0304-4203(92)90039-D
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0304-4203(92)90039-D
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“Geochemistry of suspended matter from the baltic sea : 1 : results of individual particle characterization by automated electron microprobe”. Bernard PC, Van Grieken RE, Brügmann L, Marine chemistry 26, 155 (1989). http://doi.org/10.1016/0304-4203(89)90058-3
Abstract: Automated electron probe X-ray microanalysis was used to characterize some 15 000 individual suspension particles from 50 samples of suspended matter collected from different depths at 18 stations throughout the Baltic Sea and the transient area to the North Sea. For each particle, 14 minor and major elements were determined and size information data were obtained. To process this huge amount of results, multivariate analysis techniques were invoked: the particles were classified into specific types and the abundance variations of these groups were studied. It appeared that 80% of all investigated particles contained mostly silicon, and seemed to consist of quartz, and K-rich and Fe-rich aluminosilicates. The abundance of BaSO4 particles averaged 5% throughout the Baltic Sea, but amounted to up to 44% at some stations. The abundance of the Fe-rich particles varied significantly with location and depth, and averaged ∼ 4%. They were often found to be associated with significant amounts of P. Both of these particle types and the Mn-rich particles are thought to be mainly authigenic. Calcium carbonate particles are more abundant towards the North Sea (which seems to act as a source). Principal component analysis of the data revealed that most of the compositional variability can be explained by differences between deep and surface waters and by the influences of inflowing North Sea waters. Additional information about the types and sources of the suspended matter in the Baltic Sea was gained from the comparison and correlation of the single particle results with different fractions of the bulk concentrations of elements such as Al, Ca, Mn, Fe, Zn and Ba.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0304-4203(89)90058-3
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“Kinetics of iron(II) oxidation in seawater of various pH : reply”. Roekens EJ, Van Grieken RE, Marine chemistry 15, 281 (1984). http://doi.org/10.1016/0304-4203(84)90025-2
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0304-4203(84)90025-2
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“Kinetics of iron(II) oxidation in seawater of various pH”. Roekens EJ, Van Grieken RE, Marine chemistry 13, 195 (1983). http://doi.org/10.1016/0304-4203(83)90014-2
Abstract: The rate of iron(II) oxidation in North Sea water of pH 5.510 in the range 1025°C has been studied. The oxygenation rate depends linearly on the iron(II) and dissolved oxygen concentrations. The second-order dependence on [OH−], found by several investigators for synthetic solutions, was confirmed in seawater, but only for pOH > 6.9. For pOH < 5.9 the rate appeared to be independent of the pOH. In the intermediate range, pOH 5.96.9, corresponding to the natural pH of seawater, a first-order dependence on the pOH is obeyed. The important discrepancy in the literature between the second-order rate constant for NaCHO3 solutions and for seawater can be attributed predominantly to the incorrect assumption of a second-order pOH dependence in natural seawater. The results can be useful, for example, in predicting the effect of dumping acidic iron waste from the titanium-dioxide industry into the ocean.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0304-4203(83)90014-2
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“Sulphite and sulphate concentrations in weathering products of sandy limestone and in deposition samples”. Roekens E, Bleyen C, Van Grieken R, Environmental pollution 57, 289 (1989). http://doi.org/10.1016/0269-7491(89)90084-5
Abstract: The sulphite and sulphate concentrations in weathering products of limestone and in wet and total deposition samples were measured by the modified West-Gaeke method and by ion chromatography. The sulphite content in the weathering crust and in the runoff rainwater of two historical buildings in Belgium, was always much lower than the sulphate content. The maximum sulphite to sulphate ratio was 2·5%. The sulphite concentration in wet and total deposition samples was in the low or sub ppm range except during two misty periods when the sulphite concentration was 6·8 and 21 mg litre−1. In those samples a high sulphate concentration was also found (nl. 57 and 137 mg litre−1, respectively).
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0269-7491(89)90084-5
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“The development process of an expert system for the automated interpretation of large epma data sets”. Janssens K, Dorrine W, van Espen P, Chemometrics and intelligent laboratory systems 4, 147 (1988). http://doi.org/10.1016/0169-7439(88)80086-8
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)
DOI: 10.1016/0169-7439(88)80086-8
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“PC-MCA : a software package for the acquisition and processing of spectral data”. Janssens K, Nobels J, van Espen P, Chemometrics and intelligent laboratory systems 3, 335 (1988). http://doi.org/10.1016/0169-7439(88)80033-9
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)
DOI: 10.1016/0169-7439(88)80033-9
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“AXIL-PC, software for the analysis of complex-x-ray spectra”. van Espen P, Janssens K, Nobels J, Chemometrics and intelligent laboratory systems 1, 109 (1986). http://doi.org/10.1016/0169-7439(86)80031-4
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)
DOI: 10.1016/0169-7439(86)80031-4
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“Prediction of the optical characteristics and analytical qualities of an X-ray fluorescence microprobe at the European Synchrotron Radiation Facility (Grenoble)”. van Langevelde F, Janssens KH, Adams FC, Vis RD, Nuclear instruments and methods in physics research : A: accelerators, spectrometers, detectors and associated equipment 317, 383 (1992). http://doi.org/10.1016/0168-9002(92)90632-E
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0168-9002(92)90632-E
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“Accurate evaluation of \mu-PIXE and \mu-XRF spectral data through iterative least squares fitting”. Janssens K, Vekemans B, Adams F, van Espen P, Mutsaers P, Nuclear instruments and methods in physics research: B: beam interactions with materials and atoms
T2 –, 7th International Conference on Particle Induced X-ray Emission and Its Analytical Applications, MAY 26-30, 1995, Abano Terme, Italy 109, 179 (1996). http://doi.org/10.1016/0168-583X(95)01211-7
Abstract: The integration of the nonlinear least squares X-ray spectrum evaluation progam AXIL. into a mu-PIXE and a mu-XRF setup is discussed. The use of the software when procesing data sets derived from biological and geological samples is described.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)
DOI: 10.1016/0168-583X(95)01211-7
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“Recombination reactions and geometry effects in laser microprobe mass analysis studied with 12C/13C bilayers”. Bruynseels F, Van Grieken R, International journal of mass spectrometry and ion processes 74, 161 (1986). http://doi.org/10.1016/0168-1176(86)85003-0
Abstract: Bilayers of carbon, consisting of a layer of natural carbon and a second layer highly enriched in 13C, were investigated with the LAMMA 500-® instrument. When such a bilayer is perforated by the laser beam, comparable amounts of 12C and 13C are evaporated and partly ionized so that geometry effects and recombination reactions during laser-induced ionization can straightforwardly be studied.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0168-1176(86)85003-0
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“Influence of spark generator parameters in the analysis of graphite-electrodes by spark source-mass spectrometry”. Vos L, Van Grieken R, International journal of mass spectrometry and ion processes 55, 233 (1984). http://doi.org/10.1016/0168-1176(84)87087-1
Abstract: Spark source mass spectrometric analyses of doped carbon samples were performed at different pulse lengths, pulse frequencies and breakdown voltages. The pulse length and pulse frequencies had no influence on the analysis. The relation between breakdown voltage, spark gap and sample matrix was determined. With increasing breakdown voltage, the abundance of the multiply charged ions was found to decrease, whereas the abundance of the cluster ions increased. The breakdown voltage was also found to affect the absolute and relative intensities of different elements in different manners. Interpretation of these results led to some new considerations on the phenomena in a spark discharge.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0168-1176(84)87087-1
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“Influence of ion-source geometry in spark source-mass spectrometric analysis”. Vos L, Van Grieken R, International journal of mass spectrometry and ion processes 59, 221 (1984). http://doi.org/10.1016/0168-1176(84)85098-3
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0168-1176(84)85098-3
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“Present and future applications of beam techniques in environmental microanalysis”. Jambers W, Van Grieken R, Trends in analytical chemistry 15, 114 (1996). http://doi.org/10.1016/0165-9936(95)00098-4
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0165-9936(95)00098-4
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