“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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“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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“Weathering products and surface recession rates for sandy limestones exposed to air pollution”. Roekens E, Van Raemdonck C, Leysen L, Chakravorty R, Van Grieken R page 707 (1987).
Keywords: H3 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Gevolgen van luchtverontreiniging op historische gebouwen”. Roekens E, Van Grieken R, Ons erfdeel 30, 361 (1987)
Keywords: A2 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Rates of air pollution induced surface recession and material loss for a cathedral in Belgium”. Roekens E, Van Grieken R, Atmospheric environment 23, 271 (1989). http://doi.org/10.1016/0004-6981(89)90119-4
Abstract: Runoff water samples were taken at the St. Rombout's Cathedral (Mechelen, Belgium), which was constructed with sandy limestones of Balegem and Gobertingen. Gypsum appeared to be the principal deterioration compound. The mean annual surface recession from the cathedral was calculated to be around 20 μm. Yearly several tons of stone material are flushed away from the cathedral with the rain water.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0004-6981(89)90119-4
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“Chemical characterisation of weathering crust and run-off water for a deteriorated limestone cathedral”. Roekens E, Leysen L, Van Grieken R, Komy Z, (1986)
Keywords: P3 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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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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“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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“Losses of metabolically incorporated selenium in common digestion procedures for biological material”. Robberecht HJ, Van Grieken RE, Van den Bosch PA, Deelstra H, vanden Berghe D, Talanta : the international journal of pure and applied analytical chemistry 29, 1025 (1982). http://doi.org/10.1016/0039-9140(82)80244-0
Abstract: Two common procedures for wet destruction of biological materials for subsequent determination of selenium have been investigated. Rat organs and biological fluids were endogenously labelled with 75Se to monitor losses during the procedures. Addition of nitric and perchloric acids with gradual heating up to 210° seemed to be the best method: at this temperature the labelled selenium was still recovered quantitatively, and the destruction was fast and efficient.
Keywords: A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0039-9140(82)80244-0
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“Sub-part-per-billion determination of total dissolved selenium and selenite in environmental waters by X-ray fluorescence spectrometry”. Robberecht HJ, Van Grieken RE, Analytical chemistry 52, 449 (1980). http://doi.org/10.1021/AC50053A017
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC50053A017
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“Selenium in the Belgian soils and its uptake by rye-grass”. Robberecht H, vanden Berghe D, Deelstra H, Van Grieken R, The science of the total environment 25, 61 (1982). http://doi.org/10.1016/0048-9697(82)90042-0
Abstract: Data obtained by atomic absorption spectroscopy showed a selenium concentration of only 0.11 ppm as an average value for the most representative agricultural soils in Belgium. The selenium content in rye-grass grown on different soil types was between 0.05 and 0.11 ppm, and positively correlated with the soil selenium level. Addition of selenium in the form of selenite to the different soil types resulted in an increased selenium uptake by the plant. The ultimate concentration in the plant depended on the structural and chemical composition of the soil. Twelve other elements were determined in the soils by energy-dispersive X-ray fluorescence; none showed a strong correlation with the soil selenium content or with the selenium uptake by ryegrass.
Keywords: A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0048-9697(82)90042-0
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“Selenium in environmental and drinking waters of Belgium”. Robberecht H, Van Grieken R, van Sprundel M, vanden Berghe D, Deelstra H, The science of the total environment 26, 163 (1983). http://doi.org/10.1016/0048-9697(83)90109-2
Abstract: The tetravalent and hexavalent selenium content of water samples can be determined by conventional energy-dispersive X-ray fluorescence after different preconcentration steps. Selenium values of nearly three-hundred different environmental and drinking water samples in Belgium are reported. The results are quite low, ranging from the detection limits up to 1 μg l−1. The concentration levels are compared to literature data and the speciation is discussed. The contribution of drinking water to the daily intake of selenium in Belgium ranges from less than 0.2 to 5%.
Keywords: A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0048-9697(83)90109-2
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“OPtimized selenite determination in environmental waters by X-ray fluorescence”. Robberecht H, Van Grieken R, Van der Sloot HA page 463 (1980).
Keywords: H3 Book chapter; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Evaluation of multi-element analysis of blood serum by energy-dispersive x-ray spectrometry”. Robberecht H, Van Grieken R, Shani J, Barak S, Analytica chimica acta 136, 285 (1982). http://doi.org/10.1016/S0003-2670(01)95388-7
Abstract: Conventional energy-dispersive x-ray fluorescence is applied in the analysis of blood serum to give the concentrations of 710 elements simultaneously with minimal manipulation of the samples. Simple spotting onto a Mylar carrier of 250 μl of serum, doped with two internal standards, was chosen as the sample preparation step. Some 200 serum samples, analyzed in replicate (n = 26), were used to evaluate this procedure. The detection limits are 4 μg ml-1 for K and Ca, 0.50.2 μg ml-1 for Fe, Cu, Pb and Zn, and less than 0.1 μg ml-1 for Se, Rb and Sr. Well above these limits, the standard deviation is around 10%. Comparison with the results of other measurements on the same samples indicates an accuracy of that order. The simplicity and high throughput, and the possibility of automating the x.r.f. measurements, make the proposed procedure suitable for screening large numbers of sera.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S0003-2670(01)95388-7
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“Determination of trace selenium in biological material by preconcentration and X-ray emission spectrometry”. Robberecht H, Van Grieken R, Analytica chimica acta 147, 113 (1983). http://doi.org/10.1016/0003-2670(83)80077-4
Abstract: Selenium is determined in the ng g−1 to μg g−1 range in biological and environmental samples. A wet digestion procedure was optimized with respect to volatility losses and recovery yields, by using 75Se metabolically incorporated into rat organs. Selenium is preconcentrated from the digestion liquid by a two-step reduction with 4 M HCl and ascorbic acid. The colloidal selenium formed is adsorbed on activated carbon and filtered on a Nucleopore membrane for measurement by energy-dispersive x-ray fluorescence. Almost complete recovery was obtained, and the detection limit was 20 ng, corresponding to 10 ng g−1 for a 2-g sample. Biological reference materials were analyzed with satisfactory results, and the accuracy of the method was good.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0003-2670(83)80077-4
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“Selenium content and speciation in environmental waters determied by X-ray fluorescence spectroscopy”. Robberecht H, Van Grieken R page 362 (1980).
Keywords: H3 Book chapter; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Selenium in environmental waters : determination, speciation and concentration levels”. Robberecht H, Van Grieken R, Talanta : the international journal of pure and applied analytical chemistry 29, 823 (1982). http://doi.org/10.1016/0039-9140(82)80252-X
Abstract: This article reviews the different methods used for the determination of selenium species in all types of environmental waters. Basic difficulties are discussed and the efficiency of the methods is explained in view of the sub-μg/1. concentration levels. Special attention is paid to preconcentration steps. Published data on speciation and concentration levels in various water samples are critically reviewed.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0039-9140(82)80252-X
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“Metal pollution and selenium distributions in soils and grass near a non-ferrous plant”. Robberecht H, Deelstra H, vanden Berghe D, Van Grieken R, The science of the total environment 29, 229 (1983). http://doi.org/10.1016/0048-9697(83)90093-1
Abstract: Multi-element analysis results of direct energy-dispersive X-ray fluorescence of soil samples taken in the vicinity of a non-ferrous plant in Antwerp are reported. High concentrations of Pb, Cu, Zn, As and Se are found in nearby residential areas, especially in top-soil layers. Selenium pollution appears not to be leached significantly to lower soil horizons, but it is available for uptake by rye-grass, in which toxic levels are found. Results are compared to literature data. Hydride generation atomic absorption spectrometry proved to be unsuitable for direct analysis of the heavily contaminated soils.
Keywords: A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0048-9697(83)90093-1
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“Percentage selenium in consumed belgian feeding”. Robberecht H, Deelstra H, vanden Berghe D, Van Grieken R, Revue des fermentations et des industries alimentaires 37, 188 (1982)
Keywords: A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Selenium gehalten van levensmiddelen geconsumeerd in België”. Robberecht H, Deelstra H, vanden Berghe D, Van Grieken R, Revue des fermentations et des industries alimentaires 37, 188 (1983)
Keywords: A3 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Determination of selenium in blood components by X-ray emission spectrometry”. Robberecht H, Deelstra H, Van Grieken R, Biological trace element research 25, 149 (1990). http://doi.org/10.1007/BF02990412
Abstract: Sampling, storing, sample pretreatment, and experimental conditions for selenium (Se) determination in human serum, plasma, and whole blood by X-ray emission spectrometric (XRS) methods are described. Concentration levels in these biological fluids, found by this technique, are discussed and compared to values found by other techniques for the same healthy population group in the same area. XRS analysis of blood from patients with various pathological conditions is reviewed, with special attention to the relation of Se with the concentration level of other essential or nonessential trace elements.
Keywords: A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF02990412
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“Analysis of individual environmental particles using ultra-thin window EPXMA”. Ro C-U, Osán J, Van Grieken R, (1998)
Keywords: P3 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Determination of low-Z elements in individual environmental particles using windowless EPMA”. Ro C-U, Osán J, Van Grieken R, Analytical chemistry 71, 1521 (1999). http://doi.org/10.1021/AC981070F
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC981070F
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“Determination of chemical species in individual aerosol particles using ultrathin window EPMA”. Ro C-U, Osán J, Szalóki I, Oh K-Y, Kim H, Van Grieken R, Environmental science and technology 34, 3023 (2000). http://doi.org/10.1021/ES9910661
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/ES9910661
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“A Monte Carlo program for quantitative electron-induced x-ray analysis of individual particles”. Ro C-U, Osán J, Szalóki I, de Hoog J, Worobiec A, Van Grieken R, Analytical chemistry 75, 851 (2003). http://doi.org/10.1021/AC025973R
Keywords: A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC025973R
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“Analysis of heterogeneous CaCO3-CaSO4 single particles using ultra-thin window EPMA”. Ro C-U, Oh K-Y, Van Grieken RE, (2000)
Keywords: P3 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Heterogeneity assessment in individual CaCO3-CaSO4 particles using ultrathin window electron probe X-ray microanalysis”. Ro C-U, Oh K-Y, Osán J, de Hoog J, Worobiec A, Van Grieken R, Analytical chemistry 73, 4574 (2001). http://doi.org/10.1021/AC010438X
Keywords: A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC010438X
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“Characterization of Asian dust using ultrathin window EPMA”. Ro C-U, Oh K-Y, Kim HK, Chun Y, Van Grieken R, (1999)
Keywords: P3 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Chemical speciation of individual atmospheric particles using low-Z electron probe X-ray microanalysis characterizing “Asian Dust&rdquo, deposited with rainwater in Seoul, Korea”. Ro C-U, Oh K-Y, Kim HK, Chun Y, Osán J, de Hoog J, Van Grieken R, Atmospheric environment : an international journal 35, 4995 (2001). http://doi.org/10.1016/S1352-2310(01)00287-4
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/S1352-2310(01)00287-4
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“Single-particle analysis of aerosols at Cheju Island, Korea, using low-Z electron probe X-ray microanalysis: a direct proof of nitrate formation from sea salts”. Ro C-U, Oh K-Y, Kim H, Kim YP, Lee CB, Kim K-H, Kang CH, Osán J, de Hoog J, Worobiec A, Van Grieken R, Environmental science and technology 35, 4487 (2001). http://doi.org/10.1021/ES0155231
Keywords: A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/ES0155231
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