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“Automatic absorption correction in x-ray fluorescence analysis of intermediate thickness samples using a dual external reference signal”. Van Dyck P, Markowicz A, Van Grieken R, X-ray spectrometry 9, 70 (1980). http://doi.org/10.1002/XRS.1300090209
Abstract: A method has been investigated which allows calculations from the X-ray fluorescence spectra of the absorption coefficients at any energy for any sample, without any additional measurement. Use is made of the ratio of the characteristic X-ray signals from a Zr wire positioned in front of the sample and from a Pd foil placed behind the sample, both in a fixed geometry. From the experimentally measured absorption coefficient at the Pd L energy (2.9 keV), the coefficients for higher energies are calculated. By the use of an iterative computer routine in which corrections for the enhancement of the Pd foil by the sample are also included, an accuracy of 2% or better on the absorption coefficient determination can be reached for homogenous samples in one measurement. Grain-size and heterogeneity effects induce inaccuracies on the absorption coefficient determinations which might well reach 20% for particulate samples like intermediate thickness deposits of geological materials. This approach thus has the same limitations as the classical transmission method for such heterogeneous samples.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1002/XRS.1300090209
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“Monte Carlo simulation of backscattered peaks in secondary target energy-dispersive X-ray spectra”. Van Dyck P, Török S, Van Grieken R, X-ray spectrometry 15, 231 (1986). http://doi.org/10.1002/XRS.1300150403
Abstract: A Monte Carlo simulation has been developed to describe the incoherent and coherent scatter processes for the complex geometry of a secondary target energy-dispersive x-ray fluorescence system. Photons are followed from the x-ray tube anode until the detection of scattered secondary target photons in the active Si layer of the detector. The program quantitatively shows the broadening of the incoherent scatter peak with increasing atomic number, and it models the incoherent peak shape adequately. The incoherent-to-coherent scatter intensity ratios obtained differ by 1030% from the theoretical values, while their dependence on the sample atomic number corresponds to that expected from theory.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1002/XRS.1300150403
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“Evaluation of an equation for bremsstrahlung background in electron-probe X-ray microanalysis of composite samples”. Markowicz A, Storms H, Van Grieken R, X-ray spectrometry 15, 131 (1986). http://doi.org/10.1002/XRS.1300150211
Abstract: A new equation for predicting the generated bremsstrahlung background intensity in electron-probe x-ray microanalysis has been verified experimentally. This equation is applicable to all bulk composite specimens and reduces to Kramers' equation for pure elements only. The experimental verification has been carried out for Al2O3, Fe2O3 and ZrO2 with radiation energies from 4.2 to 14.8 keV. The predicted bremsstrahlung intensities are in good agreement with the experimental data.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1002/XRS.1300150211
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“Elemental abundance variation with particle-size in north florida aerosols”. Johansson TB, Van Grieken RE, Winchester JW, Journal of geophysical research 81, 1039 (1976). http://doi.org/10.1029/JC081I006P01039
Abstract: A nonurban base line has been established for nine trace element constituents of aerosol particles as a function of particle size at ground level sampling stations in north Florida up to 50 km from the Gulf of Mexico. The particle size range 0.25- to >4-μm aerodynamic diameter was investigated by cascade impactor sampling and elemental analysis by proton-induced X ray emission. By using a strategy of sampling at urban, forest, and coastal locations and by choosing approximately 48-hour sample averaging intervals the potential dependence of the base line levels both on local pollution and natural sources and on local particle size specific aerosol removal processes could be evaluated. It is found that elements contained in the largest particles, especially those of >4 μm, display the greatest degree of average concentration difference between sites, a result suggesting short atmospheric residence times and the importance of local dispersion sources and atmospheric cleansing processes in regulating the particle concentrations in air. Elements contained in particles of <2-μm diameter show little average concentration difference between sites unless they are influenced by local pollution sources, a finding suggesting that their concentrations in air are regulated by large-scale sources and transport processes. Sulfur in the smallest particles shows a marked constancy of concentration, but it may be modified in the largest particle size ranges in relation to proximity to the seacoast. No evidence is found for dependence of particulate sulfur concentrations on local pollution sources. K, Ca, Ti, Fe, and Zn appear to be regulated in the main by terrestrial source processes, and Cl by marine source processes, but Br and Pb appear to be accounted for adequately by assuming automotive fuel combustion as their major source. Limited data obtained for V indicate that it may vary considerably with fluctuations in aerosol transport from oil-fired electric power plant sources in the region. Limited additional data also suggest that Mn is derived from sources of natural terrestrial composition. In view of these findings, certain criteria may be set for the design of a meaningful nonurban aerosol monitoring network.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1029/JC081I006P01039
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“Fast heating induced impulse halogenation of refractory sample components in electrothermal atomic absorption spectrometry by direct injection of a liquid halogenating agent”. György K, Ajtony Z, van Meel K, Van Grieken R, Czitrovszky A, Bencs L, Talanta : the international journal of pure and applied analytical chemistry 85, 1253 (2011). http://doi.org/10.1016/J.TALANTA.2011.05.028
Abstract: A novel electrothermal atomic absorption spectrometry (ETAAS) method was developed for the halogenation of refractory sample components (Er, Nd and Nb) of lithium niobate (LiNbO3) and bismuth tellurite (Bi2TeO5) optical single crystals to overcome memory effects and carry-over. For this purpose, the cleaning step of a regular graphite furnace heating program was replaced with a halogenation cycle. In this cycle, after the graphite tube cooled to room temperature, a 20 μL aliquot of liquid carbon tetrachloride (CCl4) was dispensed with a conventional autosampler into the graphite tube. The CCl4 was partially dried at 80 °C under the mini-flow (40 cm3 min−1) condition of the Ar internal furnace gas (IFG), then the residue was decomposed (pyrolyzed) by fast furnace heating at 19002100 °C under interrupted flow of the IFG. This step was followed by a clean-out stage at 2100 °C under the maximum flow of the IFG. The advantage of the present method is that it does not require any alteration to the graphite furnace gas supply system in contrast to most of the formerly introduced halogenation techniques. The effectiveness of the halogenation method was verified with the determination of Er and Nd dopants in the optical crystals. In these analyses, a sensitivity decrease was observed, which was likely due to the enhanced deterioration of the graphite tube surface. Therefore, the application of mathematical correction (resloping) of the calibration was also required. The calibration curves were linear up to 1.5 and 10 μmol L−1 for Er and Nd, respectively. Characteristic masses of 18 and 241 pg and the limit of detection (LOD) values of 0.017 and 0.27 μmol L−1 were found for Er and Nd, respectively. These LOD data correspond to 0.68 μmol mol−1 Er and 11 μmol mol−1 Nd in solid bismuth tellurite samples. The analytical results were compared with those obtained by a conventional ETAAS method and validated with X-ray fluorescence spectrometry analysis.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.TALANTA.2011.05.028
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“Background aerosol composition in the Namib Desert, South West-Africa (Namibia)”. Annegarn HJ, Van Grieken RE, Dibby DM, Von Blottnitz F, Atmospheric environment : an international journal 17, 2045 (1983). http://doi.org/10.1016/0004-6981(83)90361-X
Abstract: A remote site in the Namib Desert was selected for sampling background aerosols in southern Africa, as one of a wide network of stations spanning the Southern Hemisphere in a programme designed to measure the background concentrations of trace elements in the atmosphere. A series of samples was collected over a 6-month period using a single-orifice cascade impactor, which fractionated the particles into six size groups. Analysis was performed using particle-induced X-ray emission (PIXE), yielding results for S, Cl, K, Ca, Ti, Mn, Fe, Br and Sr, and occasionally also for V, Cr, Ni, Cu, Zn and Pb. No direct correlations with wind direction were observed excluding strong local or regional sources of particles. K, Ca, Ti, Mn and Fe can be identified with a dust dispersion source. Cl, large particle S and Br, and part of the K and Sr are derived from sea spray. Relative to the soil components small particle K is not enriched as it normally is in regions with less scarce vegetation. Cr, V, Ni, Cu, Zn and Pb concentrations and enrichments in the aerosol are lower than practically all values measured at any other location hitherto. The concentration of the small particle sulphur, 200 ng m−3, is believed to be related to anaerobic conditions and plankton blooms in the ocean upwelling zones off Namibia.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0004-6981(83)90361-X
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“Determination of sample thickness via scattered radiation in X-ray fluorescence spectrometry with filtered continuum excitation”. Araujo MF, van Espen P, Van Grieken R, X-ray spectrometry 19, 29 (1990). http://doi.org/10.1002/XRS.1300190107
Abstract: A semi-empirical approach is described for determining the mass per unit area of a sample being analysed. The method can be used to estimate the concentration of minor and trace elements in matrices containing a substantial amount of light elements. The procedure utilizes the coherently and incoherently scattered radiation induced in the sample by the filtered continuum radiation of a rhodium x-ray tube. The relationship between the intensity of the scattered radiation per unit mass and the average atomic number of the sample is established via calibration graphs, which can be applied for different x-ray tube voltages and for different primary beam filters. The overall procedure was validated by the analysis of several geological standards, deposited as thin slurries of unknown thickness either on Mylar foil or on Nuclepore filters.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)
DOI: 10.1002/XRS.1300190107
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“A simple absorption correction for electron probe X-ray microanalysis of bulk samples”. Markowicz A, Storms H, Van Grieken R, X-ray spectrometry 15, 115 (1986). http://doi.org/10.1002/XRS.1300150209
Abstract: A simple procedure is proposed for the calculation of the absorption correction factor in electron-probe x-ray microanalysis. It is based on the concept of an effective depth of x-ray production, assuming a rectangular depth distribution function for x-ray generation. This effective x-ray production depth is expressed as a fraction of the x-ray excitation depth given by Whelan's expression. Adequate values for this fraction are presented. Two versions are considered. In the first the effective x-ray production is a function of both the characteristic x-ray energy and the atomic numbers of the matrix elements, whereas in the second one, which is indicated for routine use, the energy dependence is neglected. Calculations pointed to satisfactory results, even for low x-ray energies and high overvoltages.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1002/XRS.1300150209
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“Use of theoretical accurate binary influence coefficients with Tertian's equation in X-ray fluorescence analysis of silicate rocks in borax glass beads”. Muia LM, Van Grieken R, X-ray spectrometry 19, 141 (1990). http://doi.org/10.1002/XRS.1300190311
Abstract: A study of the suitability of the Tertian algorithm using new accurate binary influence coefficients and a comparison standard for x-ray fluorescence analysis of geological materials prepared as borax glass beads was performed. The algorithm was found to give satisfactory results for the analysis of four major components in geological materials. Even in the worst case, when there is a factor of 20 difference in the concentration in the specimen and a comparison standard, the algorithm gives results which differ from the true results by a factor of about 2. This makes the algorithm attractive as a diagnostic tool in analyses of unknown specimens and in the identification of appropriate standards. The binary coefficients are easily calculated so that the algorithm can be implemented on a minicomputer.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1002/XRS.1300190311
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“Chemistry of precipitation near a limestone building”. Roekens E, Komy Z, Leysen L, Veny P, Van Grieken R, Water, air and soil pollution 38, 273 (1988). http://doi.org/10.1007/BF00280759
Abstract: A total of 82 samples of wet and total deposition were sampled near the limestone cathedral at Mechelen, Belgium, which is presently being affected seriously by air pollution, and at a reference site. Most of these samples were analyzed for 10 major and 7 trace ions in solution and for 15 elements in suspension. It appeared that calcite, released from the building, effectively neutralizes the rainwater in the near vicinity and produces high Ca and bicarbonate concentrations. Heavy metal concentrations are hardly affected by the building.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF00280759
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“Characterization of the weathering crust of various historical buildings in Belgium”. Leysen LA, Roekens EJ, Van Grieken RE, De Geyter G, The science of the total environment 90, 117 (1990). http://doi.org/10.1016/0048-9697(90)90190-6
Abstract: A variety of samples, collected from different historical buildings and monuments throughout Belgium, were thoroughly studied, using several trace- and micro-analysis techniques. Thin sections of stones and mortar joints were characterized by means of electron probe X-ray microanalysis (EPXMA). The morphological appearance of the surface weathering crust and the possible presence of non-innate particles in the crust were elucidated using petrographical and electron microscopy. Quantitative characterization of the total chemical composition of the crust surface layer and underlying layer was performed by energy-dispersive X-ray fluorescence, and by ion chromatography and atomic absorption spectrometry for the leachable components. Special attention was also paid to the chemical composition of rain and air at the particular sampling sites. The element distribution in the transition zone between the weathering crust and the original stone material was found to vary greatly amongst the different samples analyzed. Detailed EPXMA measurements on pieces of the weathering crust showed remarkable differences in morphology and composition between the surface and the underlying layer, and provided information about the presence of fly-ash and soil dust particles in the crust. Except for crusts from the city of Brussels, which were all very high in sulphate, the samples appeared to contain very variable sulphate contents; very local micro-climate and environmental conditions at a particular site are more important in determining the weathering condition of the building stones than the local air pollution situation. Bulk analytical characterization further showed, in all the crust samples studied, a very small contribution of nitrogen- and chlorine-containing weathering products, in contrast to sulphur-containing weathering salts.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0048-9697(90)90190-6
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“Spectrometric determination of silicon in food and biological samples: an interlaboratory trial”. van Dyck K, Robberecht H, van Cauwenbergh R, Deelstra H, Arnaud J, Willemyns L, Benijts F, Centeno JA, Taylor H, Soares ME, Bastos ML, Ferreira MA, d'Haese PC, Lamberts LV, Hoenig M, Knapp G, Lugowski SJ, Moens L, Riondato J, Van Grieken R, Claes M, Verheyen R, Clement L, Uytterhoeven M, Journal of analytical atomic spectrometry 15, 735 (2000). http://doi.org/10.1039/B000572J
Abstract: Accuracy and precision of silicon determination in biological matrices (serum, urine, water, beer and spinach) by spectrometric techniques (when necessary after acid destruction) were assessed by means of a collaborative interlaboratory trial. The trial was set up in accordance with ISO 5725-2 (1994). The relative overall repeatability standard deviation was acceptable. It varied between 4% for spinach powder (mean content: 176 mg kg(-1)) and 11% for serum (mean content: 5.33 mg L-1). On the other hand, the relative overall between-laboratory standard deviation was found to vary from a satisfactorily 15% for spinach after destruction (mean content: 3.32 mg L-1) to an unacceptable 107% for spinach powder (mean content: 176 mg kg(-1)). The overall conclusion of the trial was that silicon determination in biological matrices can properly be performed by spectrometric techniques. However, when sample pretreatment (i.e., acid destruction) is needed prior to silicon determination problems still remain.
Keywords: A1 Journal article; Behavioural Ecology & Ecophysiology; Pathophysiology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1039/B000572J
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“Co-crystallization with 1-(2-pyridylazo)-2-naphthol, and X-ray fluorescence, for trace metal analysis of water”. Vanderstappen MG, Van Grieken RE, Talanta : the international journal of pure and applied analytical chemistry 25, 653 (1978). http://doi.org/10.1016/0039-9140(78)80166-0
Abstract: Adding 20mg of 1-(2-pyridylazo)-2-naphthol (PAN) to a water sample at 70°, and filtering off the precipitate after cooling, gives efficient preconcentration prior to X-ray fluorescence analysis of water. Up to the capacity of about 100 μeq of PAN used, the trace metal recoveries are around 90% or higher for Cr3+, Mn2+, Ni2+, Cu2+, Zn2+, Hg2+ and Eu3+, and above 70% for many other ions. The recovery yields usually do not vary critically with pH in the neutral pH-range, and are practically independent of the sample salinity, sample volume and trace-metal concentration. Enrichment factors as high as 2 × 105 can be achieved. Counting statistics would then allow detection limits of 0.03 ppM. The blank levels in commercial PAN, however, lead to typical detection limits of about 1 ppm. The coefficient of variation is typically in the 510% range at the 10-ppM level. The accuracy and applicability of the procedure are illustrated by comparative analyses on samples of synthetic solutions, river and drinking water.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0039-9140(78)80166-0
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“Identification of individual aerosol particles containing Cr, Pb, and Zn above the North Sea”. van Malderen H, Hoornaert S, Van Grieken R, Environmental science and technology 30, 489 (1996). http://doi.org/10.1021/ES950205L
Abstract: Aerosol samples have been collected over the southern bight of the North Sea from an aircraft. In this way, 96 samples were taken for single-particle analysis during 16 flights. Almost 45 000 individual particles were analyzed with electron probe X-ray microanalysis. More than 5000 of these were found to contain significant concentrations of one or more of the heavy metals Cr, Pb, and Zn. With the help of hierarchical, nonhierarchical, and fuzzy clustering techniques, various heavy metal-containing particle types could be identified. Significant differences in abundances were detected in the North Sea heavy metal aerosol, depending on the origin of the air masses. In samples with continental influence 50 times more Zn- and Pb-containing particles were found than in samples with a marine history. For Cr, on the other hand, we found abundances in the marine sector that were one-third of the values for continental sectors. This might point to a rather undefined marine source, which could be the recycling of previously deposited material by reinjection into the atmosphere by sea spray. The highest values for Cr-, Pb-, and Zn-containing particles were always detected under southeastern wind directions.
Keywords: A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/ES950205L
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“Composition and sources of aerosols from the Amazon basin”. Artaxo P, Storms H, Bruynseels F, Van Grieken R, Maenhaut W, Journal of geophysical research 93, 1605 (1988). http://doi.org/10.1029/JD093ID02P01605
Abstract: Aerosols were sampled in the Amazon Basin, as part of the Global Tropospheric Experiment (GTE), during the Amazon Boundary Layer Experiment (ABLE 2A) in JulyAugust 1985. Fine- and coarse-particle fractions were analyzed for 22 elements by particle-induced X ray emission. Gravimetric mass, black carbon, sulfate, and nitrate concentrations were also determined. Morphological and trace element measurements of individual particles were carried out by automated electron probe X ray microanalysis. Various receptor models, including multivariate methods and a chemical mass balance model, were employed in the interpretation of the bulk trace element concentrations. Three factors explained over 85% of the variability of fine- and coarse-mode variables. On the basis of the elemental composition of the factors, two could be identified as plant related, and the third was a soil dust component. Of the coarse-mode aerosol mass concentration (of 7.6±1.6 μg/m3), 62% could be attributed to aerosols released by the vegetation and 11% to soil dust. In the fine mode, soil dust accounted for less than 10% of the measured mass concentration (of 6.8±3.9 μg/m3). The variables related to the plant component were K, P, S, Ca, Mg, Cl, Rb, and the gravimetric mass. The elemental profile of the plant component resembled the bulk plant composition. By single-particle analysis coupled with hierarchical cluster analysis, six to nine different biogenic-related particle groups could be identified in the fine- and coarse-aerosol modes. Almost all particle types consisted predominantly of carbonaceous material, with trace amounts of K, S, Ca, P, Cl, and Na. Only one group, comprising less than 11% of the total number of particles, consisted of soil dustrelated aerosol.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1029/JD093ID02P01605
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“The elemental composition of airborne particulate matter in the Atacama desert, Chile”. Rojas CM, Figueroa L, Janssens KH, Van Espen PE, Adams FC, Van Grieken RE, The science of the total environment 91, 251 (1990). http://doi.org/10.1016/0048-9697(90)90302-B
Abstract: Air particulate samples were collected at Chapiquiña near Arica (Chile) with a six-stage cascade impactor for about 17-day periods during a 31 month interval. Sixteen elements were determined by energy dispersive X-ray fluorescence analysis, and the elemental concentrations were subjected to principal factor analysis. The variability with time of the coarse particles was described by two factors both related to soil dispersion, whereas the fine particle variations could be explained by a third factor related to marine influence. Enrichment factors were compared with those obtained in other remote continental areas, in particular those of air particulate matter sampled at Chacaltaya, Bolivia. Results point to a negligible anthropogenic influence.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0048-9697(90)90302-B
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“Inhable particulate matter from lime industries: chemical composition and deposition in human respiratory tract”. Godoi RHM, Braga DM, Makarovska Y, Alfoldy B, Carvalho Filho MAS, Van Grieken R, Godoi AFL, Atmospheric environment : an international journal 42, 7027 (2008). http://doi.org/10.1016/J.ATMOSENV.2008.07.002
Abstract: Air pollution caused by the lime production industry has become a serious problem with potential effects to human health, especially in developing countries. Colombo is a city included in the Metropolitan Region of Curitiba (capital of Parana State) in South Brazil. In Colombo city, a correlation has been shown between the lime production and the number of persons who need respiratory treatment in a local hospital, indicating that the lime industry can cause deleterious health effects in the exposed workers and population. This research was conducted to deal firstly with the characterization of the size distribution and chemical compositions of particles emitted from lime manufacturing and subsequently to assess the deposition rate of inhaled dolomitic lime aerosol particles in the human respiratory tract. The elemental chemical composition and particle size of individual atmospheric particles was quantitatively elucidated, including low-Z components like C, N and 0, as well as higher-Z elements, using automated electron probe microanalysis. Information concerning the bulk composition is provided by energy-dispersive X-ray detection. The majority of the respirable particulate matter identified was composed of aluminosilicates, Ca-Mg oxides, carbon-rich particles, mixtures of organic particles and Ca-Mg carbonates, soot and biogenic particles. In view of the chemical composition and size distribution of the aerosol particles, local deposition efficiencies in the human respiratory system were calculated, revealing the deposition of CaO center dot MgO at extrathoracic, tracheobronchial and pulmonary levels. The results of this study offer evidence to the threat of the fine and coarse particles emitted from dolomite lime manufacturing, allowing policy-makers to better focus their mitigation strategies in an effective way, as well as to the dolomite producers for the purpose of designing and/or implementing improved emission controls.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.ATMOSENV.2008.07.002
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“Composition and size of individual particles from a gold mine atmosphere”. Annegarn HJ, Storms H, Van Grieken RE, Booth-Jones PA, Mining science &, technology 5, 111 (1987). http://doi.org/10.1016/S0167-9031(87)90345-8
Abstract: Airborne dust particles were collected in a return airway of a South African gold mine using a 7-stage, single-orifice cascade impactor. Between 70 and 130 individual particles were analysed on each stage using automated electron-probe x-ray microanalysis (EPXMA). Particle size and shape parameters are given for different classes of particles sorted by elemental composition. Silicon-rich particles are the most abundant overall, while chlorine-rich particles dominate (up to 80%) in the range 0.21.0 μm. It is shown that EPXMA characterisation of particles can be used to infer relative contributions of various particle sources and dust generating processes to the total dust concentrations in mine atmospheres. An understanding of the nature and source of particles is essential for any source control strategy. We conclude that the EPXMA technique merits inclusion in the repertoire of techniques used for characterising underground dust.
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S0167-9031(87)90345-8
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“Preconcentration methods for the analysis of water by X-ray spectrometric techniques”. Van Grieken R, Analytica chimica acta 143, 3 (1982). http://doi.org/10.1016/S0003-2670(01)95486-8
Abstract: All published procedures for multi-element preconcentration of trace elements, prior to x-ray fluorescence analysis of water, are reviewed and critically evaluated. Most preconcentration methods applied to the determination of single elements in water are also listed.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S0003-2670(01)95486-8
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“Occupational allergic contact dermatitis from bisphenol A in vinyl gloves”. Matthieu L, Godoi AFL, Lambert J, Van Grieken R, Contact dermatitis 49, 281 (2003). http://doi.org/10.1111/J.0105-1873.2003.0241.X
Abstract: Allergic contact dermatitis caused by polyvinyl chloride gloves is rarely reported, and in only 2 cases was bisphenol A considered to be the responsible sensitizer. We report a patient with occupational hand dermatitis after the use of a new type of high-density vinyl (HDV) gloves. Patch tests showed positive (++) reactions to both used and new HDV gloves and to bisphenol A. Chemical analysis by gas chromatography-mass spectrometry demonstrated the presence of bisphenol A in the HDV gloves. Replacement by nitrile rubber gloves resulted in complete clearance of the hand dermatitis.
Keywords: A1 Journal article; Translational Pathophysiological Research (TPR); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1111/J.0105-1873.2003.0241.X
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“Analysis of geothermal waters by spark source mass spectrometry”. Vandelannoote R, Blommaert W, Gijbels R, van Grieken R, Fresenius' Zeitschrift für analytische Chemie 309, 291 (1981). http://doi.org/10.1007/BF00488604
Abstract: Although the analysis of thermal water by spark-source mass spectrometry (SSMS) is rather timeconsuming, it allows the detection of about 20 elements of geochemical interest down to the ppb-level. A physical preconcentration is proposed in order to collect elements having quite different chemical properties, e.g. alkalis, transition elements, and elements occurring in anionic form. The relative sensitivity factors appear to be rather independent of the salt content of the graphite electrodes. Contrary to neutron activation analysis, SSMS has a quite uniform elemental sensitivity, and allows to determine elements for which neutron activation is not suitable, e.g. Sn and Pb. The precision of SSMS is however by a factor of about 2 worse than that obtained for neutron activation.
Keywords: A3 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Times cited: 8
DOI: 10.1007/BF00488604
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“Study of inorganic ammonium compounds in individual marine aerosol particles by laser microprobe mass spectrometry”. Otten P, Bruynseels F, Van Grieken R, Analytica chimica acta 195, 117 (1987). http://doi.org/10.1016/S0003-2670(00)85654-8
Abstract: Ammonia is important in the atmosphere because it neutralizes acidic species. The relative importance of different inorganic ammonium compounds (chloride, nitrate and sulfate) in marine air chemistry was studied by single-particle characterization with the laser microprobe mass analyser. Standard aerosols were generated as a reference for compound identification, based on the fingerprint spectra obtained, and calculation of the relative sensitivity achieved for different ions in a marine aerosol matrix. The relative sensitivity for ammonium was low. Aerosol samples were collected in the Southern Bight of the North Sea under different meteorological conditions and examined for their ammonium compounds. Samples collected during an inversion period with continental influences showed a much higher content in all particles than samples collected under different meteorological conditions, where ammonium was mostly detected in the submicrometer particle-size range.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S0003-2670(00)85654-8
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“Automated quantitative electron-microprobe analysis of particulate material”. Van Dyck P, Storms H, Van Grieken R, Journal de physique 45, 781 (1984). http://doi.org/10.1051/JPHYSCOL:19842179
Abstract: An automated electron microprobe, equipped with an energy-dispersive X-ray spectrometer and an additional backscattered electron signal digitalization system, can allow rapid sizing and major element analysis on numerous particles. A software package has been developed to exploit the particle size and shape information to achieve quantitative analysis of single particles, and to compare the performance of the different matrix correction procedures.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1051/JPHYSCOL:19842179
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“Theoretical evaluation of the effective alpha and De Jongh approaches in X-ray fluorescence analysis of geological materials in borax glass beads”. Muia LM, Van Grieken R, X-ray spectrometry 18, 259 (1989). http://doi.org/10.1002/XRS.1300180604
Abstract: An evaluation of the accuracy and suitability of the LachanceTraill algorithm using effective α-coefficients, and the De Jongh α approach for x-ray fluorescence analysis of borax glass beads prepared from geological material was performed. By using theoretical α-coefficients obtained from the same standard and calculated elemental intensities, the two algorithms were compared under identical conditions. When only the monitor standard is used, the LachanceTrail1 approach is found to be inferior to the De Jongh basic α method. If multi-standard calibration is performed for both approaches, the accuracies are almost identical and no significant difference is found in the results. The LachanceTraill algorithm has the advantage of being easier to implement on a minicomputer and, when used without standards, it is found to give results within a few percent of the true values, which is a useful indicator in the choice of appropriate standards for more accurate analytical work.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1002/XRS.1300180604
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“Acute changes in pulse pressure in relation to constituents of particulate air pollution in elderly persons”. Jacobs L, Buczyńska A, Walgraeve C, Potgieter-Vermaak S, Van Grieken R, et al, Environmental research 117, 60 (2012). http://doi.org/10.1016/J.ENVRES.2012.05.003
Abstract: An increased pulse pressure (difference between systolic and diastolic blood pressure) suggests aortic stiffening. The objective of this study was to examine the acute effects of both particulate matter (PM) mass and composition on blood pressure, among elderly persons. We carried out a panel study in persons living in elderly homes in Antwerp, Belgium. We recruited 88 non-smoking persons, 70% women with a mean age of 83 years (standard deviation: 5.2). Blood pressure was measured and a blood sample was collected on two time points, which were chosen so that there was an exposure contrast in ambient PM exposure. The elemental content of the collected indoor and outdoor PM2.5 (particulate matter with an aerodynamic diameter <2.5 μm) mass concentration was measured. Oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) on outdoor PM10 (particulate matter with an aerodynamic diameter <10 μm) were measured. Each interquartile range increase of 20.8 μg/m³ in 24-h mean outdoor PM2.5 was associated with an increase in pulse pressure of 4.0 mmHg (95% confidence interval: 1.86.2), in persons taking antihypertensive medication (n=57), but not in persons not using antihypertensive medication (n=31) (p for interaction: 0.02). Vanadium, iron and nickel contents of PM2.5 were significantly associated with systolic blood pressure and pulse pressure, among persons on antihypertensive medication. Similar results were found for indoor concentrations. Of the oxy-PAHs, chrysene-5,6-dione and benzo[a]pyrene-3,6-dione were significantly associated with increases in systolic blood pressure and pulse pressure. In elderly, pulse pressure was positively associated with acute increases in outdoor and indoor air pollution, among persons taking antihypertensive medication. These results might form a mechanistic pathway linking air pollution as a trigger of cardiovascular events.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/J.ENVRES.2012.05.003
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“Radio-isotope neutron activation analysis for vanadium, manganese and tungsten in alloy steels”. Lins Galdino SM, Costa Dantas C, Van Grieken R, Analytica chimica acta 196, 337 (1987). http://doi.org/10.1016/S0003-2670(00)83107-4
Abstract: An instrumental neutron activation method for V, Mn and W in alloy steels with a 241 Am/Be isotopic neutron source is described. The samples were irradiated to induce the nuclear reactions 51V(n, γ) 52V, 55Mn(n, γ)56Mn, and 186W(n, γ)187W. The activities were measured with a NaI(TI) detector. Interferences on the measured photopeaks were shown to be negligible by measuring the half-lives of 62V, 56Mn and 187W.These thre elementes were determined in the range 1.512.9% in special steels; manganese in the range 0.51.6% was measured in cast irons. Calibration was done by comparison with results from wet chemistry and x-ray fluorescence spectrometry. The processing times for the vanadium, manganese and tungsten determinations were 11 min, 3 h and 26.3 h, respectively, but these were reduced greatly by intoruding a scheme wherein six samples were simultaneously irradiated and the 56Mn and 187W nuclides were measured sequentially for a series of 66 samples. The average processing time was reduced to 45 min for tungsten with a precision of 4.0% and accuracy of 3.4% and 22.8 min for manganese with a precision of 3.8% and accuracy of 3.1%.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S0003-2670(00)83107-4
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“Effects of titanium dioxide industry waste dumping on sea water chemistry”. Roekens EJ, Van Grieken RE, Water research 17, 1385 (1983). http://doi.org/10.1016/0043-1354(83)90268-3
Abstract: An investigation was made to determine the influence of the dumping of a 1000 ton day−1, on the average, of acid-iron waste from the titanium dioxide industry into the shallow but turbulent Southern Bight of the North Sea. This waste contains some 20% sulfuric acid and 2% iron. After the passage of the barge that discharges 10 ton of waste min−1 into its wake, the vertical and horizontal distributions of the pH, iron-concentration and turbidity were measured as a function of time. It appeared that a few seconds after the discharge and for a very brief period, the pH was down to approx. 4 and the Fe-concentration was 13 mg l−1. More than 1 min after the discharge a pH below 6 and an iron-level above 3 mg l−1 could not be detected anywhere. The measured factor for waste dilution by sea water, based on the observed acid and iron concentration in the waste and in the discharge track, were around 5000 after 5 min, 9000 after 10 min and 80,000 after 20 min. Before and long after the dumping, the total iron-concentration in this Southern Bight area was around 100 μg l−1, but this high level might be due to natural causes.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0043-1354(83)90268-3
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“Total analysis of plant material and biological tissue by spark source mass spectrometry”. Verbueken A, Michiels E, Van Grieken R, Fresenius' Zeitschrift für analytische Chemie 309, 300 (1981). http://doi.org/10.1007/BF00488606
Abstract: Analysis of biological material by spark source mass spectrometry is reported. Preliminary studies mainly based upon the analysis of the NBS standard reference material SRM-1571 (Orchard Leaves) are described. Attention is drawn to the importance of a suitable sample preparation method. The advantages of a wet digestion technique in a Teflon bomb are discussed and its use is justified by the satisfactory overall analysis precision of about 20%.
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF00488606
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“X-ray spectrometry for preventive conservation of cultural heritage”. Van Grieken R, Worobiec A, Pramåna: a journal of physics 72, 191 (2011). http://doi.org/10.1007/S12043-011-0041-3
Abstract: Analytical chemistry does play a key role in the chemical characterization of the environment and it appears that X-ray spectrometry, in its many forms, is one of the most relevant analytical techniques in preventive conservation, as it is in cultural heritage research in general. X-ray spectrometry has indeed been the method of choice for the characterization of the inorganic composition of atmospheric aerosols, for a long time. We have, over the last decade, intensively used various forms of X-ray spectrometry, viz., mostly energy-dispersive X-ray fluorescence, e.g. with polarized high-energy beam excitation, and automated electron probe X-ray microanalysis, together with other techniques, to identify particle types and their sources in indoor environments, including museums, while gaseous indoor pollutants were assessed using passive diffusion samplers. In each case, both bulk aerosols and individual aerosol particles were studied. For microanalysis of single particles, we have investigated a dozen techniques, but for wide, real-life applications, automated electron probe X-ray microanalysis is the most rewarding. We have first studied atmospheric aerosols in and around the Correr Museum in Venice, many other museums in Austria, Japan and England, and in the caves with prehistoric rock paintings in Altamira, Spain. Very recently, measurements were done in the Metropolitan Museum of Art in New York and theWawel Castle in Cracow, in Italian and Polish mountain churches, in a number of museums in Belgium and the Netherlands, and in cathedrals with medieval stained glass windows. In the Correr museum, it appeared that the particles most threatening for the Bellini paintings were released by the deteriorating plaster renderings, and this could be avoided by simply improving the rendering on the museum walls. In the Wawel Castle, outdoor pollution particles, like fine soot from diesel traffic, entering via leaks in the windows and doors, and also street-deicing salts and coal burning pollution particles, brought in by visitors, mostly in winter, were found to be most worrisome. Urgent questions that are not solved at this moment pertain to the deposition processes from the atmosphere to the cultural heritage items, the critical surface interactions that take place on these items, and the establishment of suitable particle concentration standards.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP)
DOI: 10.1007/S12043-011-0041-3
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“Investigation of heterogeneous reactions of PAH's on particle surfaces using laser microprobe mass analysis”. Niessner R, Klockow D, Bruynseels F, Van Grieken R, International journal of environmental analytical chemistry 22, 281 (1985). http://doi.org/10.1080/03067318508076427
Abstract: Artificially generated NaCl particles were coated with PAH's by using a condensation technique. These particles were exposed to reactive gases like ozone, bromine and nitrogen dioxide. The original as well as the exposed particles were investigated by fluorimetric analysis and by LAMMA (Laser Microprobe Mass Analysis) in the desorption mode, which allows the evaporation and characterization of surfaces of single particles. The results are interpreted in terms of possible heterogeneous atmospheric reactions. The reactivity of the considered PAH's towards nitrogen dioxide was found to be negligible. The structure of the reaction products formed with ozone was partially elucidated.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1080/03067318508076427
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