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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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“Casting light on the darkening of colors in historical paintings”. da Pieve F, Hogan C, Lamoen D, Verbeeck J, Vanmeert F, Radepont M, Cotte M, Janssens K, Gonze X, Van Tendeloo G, Physical review letters 111, 208302 (2013). http://doi.org/10.1103/PhysRevLett.111.208302
Abstract: The degradation of colors in historical paintings affects our cultural heritage in both museums and archeological sites. Despite intensive experimental studies, the origin of darkening of one of the most ancient pigments known to humankind, vermilion (α-HgS), remains unexplained. Here, by combining many-body theoretical spectroscopy and high-resolution microscopic x-ray diffraction, we clarify the composition of the damaged paint work and demonstrate possible physicochemical processes, induced by illumination and exposure to humidity and air, that cause photoactivation of the original pigment and the degradation of the secondary minerals. The results suggest a new path for the darkening process which was never considered by previous studies and prompt a critical examination of their findings.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 8.462
Times cited: 30
DOI: 10.1103/PhysRevLett.111.208302
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“Colloquium Spectroscopicum Internationale 34, Antwerp, Belgium, 4-9 September 2005: preface”. Janssens K, Bogaerts A, van Grieken R, Talanta : the international journal of pure and applied analytical chemistry 70, 907 (2006). http://doi.org/10.1016/j.talanta.2006.05.044
Keywords: Editorial; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 4.162
DOI: 10.1016/j.talanta.2006.05.044
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“Colloquium Spectroscopicum Internationale 34, Antwerp (Belgium), 4-9 September 2005: preface”. Bogaerts A, Janssens K, van Grieken R, Spectrochimica acta: part B : atomic spectroscopy 61, 373 (2006). http://doi.org/10.1016/j.sab.2006.04.011
Keywords: Editorial; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 3.241
Times cited: 2
DOI: 10.1016/j.sab.2006.04.011
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“Editorial”. van Grieken R, Bogaerts A, Janssens K, Spectrochimica acta: part A: molecular spectroscopy 64, 1089 (2006). http://doi.org/10.1016/j.saa.2006.05.011
Keywords: Editorial; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 2.536
DOI: 10.1016/j.saa.2006.05.011
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“Enamels in stained glass windows: preparation, chemical composition, microstructure and causes of deterioration”. Schalm O, van der Linden V, Frederickx P, Luyten S, van der Snickt G, Caen J, Schryvers D, Janssens K, Cornelis E, van Dyck D, Schreiner M, Spectrochimica acta: part B : atomic spectroscopy 64, 812 (2009). http://doi.org/10.1016/j.sab.2009.06.005
Abstract: Stained glass windows incorporating dark blue and purple enamel paint layers are in some cases subject to severe degradation while others from the same period survived the ravages of time. A series of dark blue, greenblue and purple enamel glass paints from the same region (Northwestern Europe) and from the same period (16early 20th centuries) has been studied by means of a combination of microscopic X-ray fluorescence analysis, electron probe micro analysis and transmission electron microscopy with the aim of better understanding the causes of the degradation. The chemical composition of the enamels diverges from the average chemical composition of window glass. Some of the compositions appear to be unstable, for example those with a high concentration of K2O and a low content of CaO and PbO. In other cases, the deterioration of the paint layers was caused by the less than optimal vitrification of the enamel during the firing process. Recipes and chemical compositions indicate that glassmakers of the 1617th century had full control over the color of the enamel glass paints they made. They mainly used three types of coloring agents, based on Co (dark blue), Mn (purple) and Cu (light-blue or greenblue) as coloring elements. Bluepurple enamel paints were obtained by mixing two different coloring agents. The coloring agent for redpurple enamel, introduced during the 19th century, was colloidal gold embedded in grains of lead glass.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Vision lab
Impact Factor: 3.241
Times cited: 28
DOI: 10.1016/j.sab.2009.06.005
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“L'analyse des eaux géothermales par spectrométrie de masse à, étincelles”. Vandelannoote R, Blommaert W, van Grieken R, Gijbels R, Spectra 2000: la revue de l'instrumentation 53, 66 (1979)
Keywords: A3 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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Gijbels R, van Grieken R (1977) Application of analytical methods for trace elements in geothermal waters : part 1 : Amélie-les-Bains (Eastern Pyrenees). S.l
Keywords: MA3 Book as author; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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Gijbels R, van Grieken R, Blommaert W, Van 't dack L, van Espen P, Nullens H, Saelens R (1983) Application of analytical methods for trace elements in geothermal waters : part 2 : Plombières, Bains-les-Bains, Bourbonne (Vosges). S.l
Keywords: MA3 Book as author; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)
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van Grieken R, Gijbels R, Speecke A, Hoste J (1971) Determination of oxygen, silicon, phosphorus and copper in iron and steel by 14 MeV neutron activation analysis. S.l
Keywords: MA3 Book as author; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Experimental weathering studies of igneous rocks (alkali-granite, granodiorite, gabbro and granite) and sedimentary gneiss under hydrothermal conditions”. Van 't dack L, Beusen J-M, Claesson T, Vandelannoote R, van Grieken R, Gijbels R, , 363 (1985)
Keywords: P3 Proceeding; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Geothermal water analysis by X-ray fluorescence and neutron activation”. van Grieken R, Gijbels R, Blommaert W, Vandelannoote R, Van 't dack L US Energy Research and Development Administration, S.l., page 368 (1978).
Keywords: H3 Book chapter; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Trace element geochemistry in thermal waters from Amélie-les-Bains (Eastern Pyrenees, France)”. Gijbels R, van Grieken R, Vandelannoote R, Blommaert W, Van 't dack L, , 123 (1980)
Keywords: P3 Proceeding; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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Gijbels R, van Grieken R (1985) Trace element geochemistry in thermal waters from the Eastern Pyrenees. S.l
Keywords: MA3 Book as author; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Inorganic mass spectrometry”. Adams F, Gijbels R, van Grieken R, Kim Y-sang Freedom Academy Press, Seoul (1999).
Keywords: ME3 Book as editor; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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Adams F, Gijbels R, Van Grieken R, Dachang Z (1993) Inorganic mass spectrometry. Fudan University Press, Shanghai, 391 p
Keywords: MA3 Book as author; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Nanoscale morphology of a piece of ruby red Kunckel glass”. Fredrickx P, Schryvers D, Janssens K, Physics and chemistry of glasses 43, 176 (2002)
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Equilibrium constants for trace elements in natural waters”. Van 't dack L, Blommaert W, Vandelannoote R, Gijbels R, van Grieken R, Reviews in analytical chemistry 7, 297 (1983)
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
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“Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods : 3 : synthesis, characterization, and detection of different crystal forms of the chrome yellow pigment”. Monico L, Janssens K, Miliani C, Brunetti BG, Vagnini M, Vanmeert F, Falkenberg G, Abakumov A, Lu Y, Tian H, Verbeeck J, Radepont M, Cotte M, Hendriks E, Geldof M, van der Loeff L, Salvant J, Menu M;, Analytical chemistry 85, 860 (2013). http://doi.org/10.1021/ac302158b
Abstract: The painter, Vincent van Gogh, and some of his contemporaries frequently made use of the pigment chrome yellow that is known to show a tendency toward darkening. This pigment may correspond to various chemical compounds such as PbCrO4 and PbCr1-xSxO4, that may each be present in various crystallographic forms with different tendencies toward degradation. Investigations by X-ray diffraction (XRD), mid-Fourier Transform infrared (FTIR), and Raman instruments (benchtop and portable) and synchrotron radiation-based micro-XRD and X-ray absorption near edge structure spectroscopy performed on oil-paint models, prepared with in-house synthesized PbCrO4 and PbCr1-xSxO4, permitted us to characterize the spectroscopic features of the various forms. On the basis of these results, an extended study has been carried out on historic paint tubes and on embedded paint microsamples taken from yellow-orange/pale yellow areas of 12 Van Gogh paintings, demonstrating that Van Gogh effectively made use of different chrome yellow types. This conclusion was also confirmed by in situ mid-FTIR investigations on Van Goghs Portrait of Gauguin (Van Gogh Museum, Amsterdam).
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 6.32
Times cited: 79
DOI: 10.1021/ac302158b
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“Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods : 1 : artificially aged model samples”. Monico L, van der Snickt G, Janssens K, de Nolf W, Miliani C, Verbeeck J, Tian H, Tan H, Dik J, Radepont M, Cotte M, Analytical chemistry 83, 1214 (2011). http://doi.org/10.1021/ac102424h
Abstract: On several paintings by artists of the end of the 19th century and the beginning of the 20th Century a darkening of the original yellow areas, painted with the chrome yellow pigment (PbCrO4, PbCrO4·xPbSO4, or PbCrO4·xPbO) is observed. The most famous of these are the various Sunflowers paintings Vincent van Gogh made during his career. In the first part of this work, we attempt to elucidate the degradation process of chrome yellow by studying artificially aged model samples. In view of the very thin (1−3 μm) alteration layers that are formed, high lateral resolution spectroscopic methods such as microscopic X-ray absorption near edge (μ-XANES), X-ray fluorescence spectrometry (μ-XRF), and electron energy loss spectrometry (EELS) were employed. Some of these use synchrotron radiation (SR). Additionally, microscopic SR X-ray diffraction (SR μ-XRD), μ-Raman, and mid-FTIR spectroscopy were employed to completely characterize the samples. The formation of Cr(III) compounds at the surface of the chrome yellow paint layers is particularly observed in one aged model sample taken from a historic paint tube (ca. 1914). About two-thirds of the chromium that is present at the surface has reduced from the hexavalent to the trivalent state. The EELS and μ-XANES spectra are consistent with the presence of Cr2O3·2H2O (viridian). Moreover, as demonstrated by μ-XANES, the presence of another Cr(III) compound, such as either Cr2(SO4)3·H2O or (CH3CO2)7Cr3(OH)2 [chromium(III) acetate hydroxide], is likely.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 6.32
Times cited: 113
DOI: 10.1021/ac102424h
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“Unique opto-electronic structure and photo reduction properties of sulfur doped lead chromates explaining their instability in paintings”. Rahemi V, Sarmadian N, Anaf W, Janssens K, Lamoen D, Partoens B, De Wael K, Analytical chemistry 89, 3326 (2017). http://doi.org/10.1021/ACS.ANALCHEM.6B03803
Abstract: Chrome yellow refers to a group of synthetic inorganic pigments that became popular as an artists material from the second quarter of the 19th century. The color of the pigment, in which the chromate ion acts as a chromophore, is related to its chemical composition (PbCr1-xSxO4, with 0≤x≤0.8) and crystalline structure (monoclinic/orthorhombic). Their shades range from the yellow-orange to the paler yellow tones with increasing sulfate amount. These pigments show remarkable signs of degradation after limited time periods. Pure PbCrO4 (crocoite in its natural form) has a deep yellow color and is relatively stable, while the co-precipitate with lead sulfate (PbCr1-xSxO4) has a paler shade and seems to degrade faster. This degradation is assumed to be related to the reduction of Cr(VI) to Cr(III). We show that on increasing the sulfur(S)-content in chrome yellow, the band gap increases. Typically, when increasing the band gap, one might assume that a decrease in photo activity is the result. However, the photo activity relative to the Cr content, and thus Cr reduction, of sulfur-rich PbCr1-xSxO4 is found to be much higher compared to the sulfur-poor or non-doped lead chromates. This discrepancy can be explained by the evolution of the crystal and electronic structure as function of the sulfur content: first-principles density functional theory calculations show that both the absorption coefficient and reflection coefficients of the lead chromates change as a result of the sulfate doping in such a way that the generation of electron-hole pairs under illumination relative to the total Cr content increases. These changes in the material properties explain why paler shade yellow colors of this pigment are more prone to discoloration. The electronic structure calculations also demonstrate that lead chromate and its co-precipitates are p-type semiconductors, which explains the observed reduction reaction. As understanding this phenomenon is valuable in the field of cultural heritage, this study is the first joint action of photo-electrochemical measurements and first-principles calculations to approve the higher tendency of sulfur-rich lead chromates to darken.
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 6.32
Times cited: 7
DOI: 10.1021/ACS.ANALCHEM.6B03803
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“Nanoscale investigation of the degradation mechanism of a historical chrome yellow paint by quantitative electron energy loss spectroscopy mapping of chromium species”. Tan H, Tian H, Verbeeck J, Janssens K, Van Tendeloo G, Angewandte Chemie: international edition in English 52, 11360 (2013). http://doi.org/10.1002/anie.201305753
Abstract: Getting the picture: The investigation of 100 year old chrome yellow paint by transmission electron microscopy and spectroscopy has led to the identification of four types of coreshell particles. This nanoscale investigation has allowed a mechanism to be proposed for the darkening of some bright yellow colors in Van Gogh's paintings (e.g. in Falling leaves (Les Alyscamps), 1888).
Keywords: A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 11.994
Times cited: 29
DOI: 10.1002/anie.201305753
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