|
“Spatially resolved (semi)quantitative determination of iron (Fe) in plants by means of synchrotron micro X-ray fluorescence”. Terzano R, Alfeld M, Janssens K, Vekemans B, Schoonjans T, Vincze L, Tomasi N, Pinton R, Cesco S, Analytical and bioanalytical chemistry 405, 3341 (2013). http://doi.org/10.1007/S00216-013-6768-6
Abstract: Iron (Fe) is an essential element for plant growth and development; hence determining Fe distribution and concentration inside plant organs at the microscopic level is of great relevance to better understand its metabolism and bioavailability through the food chain. Among the available microanalytical techniques, synchrotron mu-XRF methods can provide a powerful and versatile array of analytical tools to study Fe distribution within plant samples. In the last years, the implementation of new algorithms and detection technologies has opened the way to more accurate (semi)quantitative analyses of complex matrices like plant materials. In this paper, for the first time the distribution of Fe within tomato roots has been imaged and quantified by means of confocal mu-XRF and exploiting a recently developed fundamental parameter-based algorithm. With this approach, Fe concentrations ranging from few hundreds of ppb to several hundreds of ppm can be determined at the microscopic level without cutting sections. Furthermore, Fe (semi)quantitative distribution maps were obtained for the first time by using two opposing detectors to collect simultaneously the XRF radiation emerging from both sides of an intact cucumber leaf.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 3.431
Times cited: 27
DOI: 10.1007/S00216-013-6768-6
|
|
|
“X-ray spectrometry”. Török S, Labar J, Schmeling M, Van Grieken R, Analytical chemistry 70, 495r (1998)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
|
|
|
“X-ray spectrometry”. Török SB, Labar J, Injuk J, Van Grieken RE, Analytical chemistry R68, 467 (1996)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
|
|
|
“X-ray spectrometry”. Török SB, Van Grieken RE, Analytical chemistry 64r, 180 (1992)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
|
|
|
“Nanobody-based immunosensor detection enhanced by photocatalytic-electrochemical redox cycling”. Trashin S, Morales-Yánez F, Thiruvottriyur Shanmugam S, Paredis L, Carrión EN, Sariego I, Muyldermans S, Polman K, Gorun SM, De Wael K, Analytical Chemistry 93, 13606 (2021). http://doi.org/10.1021/ACS.ANALCHEM.1C02876
Abstract: Detection of antigenic biomarkers present in trace amounts is of crucial importance for medical diagnosis. A parasitic disease, human toxocariasis, lacks an adequate diagnostic method despite its worldwide occurrence. The currently used serology tests may stay positive even years after a possibly unnoticed infection, whereas the direct detection of a re-infection or a still active infection remains a diagnostic challenge due to the low concentration of circulating parasitic antigens. We report a time-efficient sandwich immunosensor using small recombinant single-domain antibodies (nanobodies) derived from camelid heavy-chain antibodies specific to Toxocara canis antigens. An enhanced sensitivity to pg/mL levels is achieved by using a redox cycle consisting of a photocatalytic oxidation and electrochemical reduction steps. The photocatalytic oxidation is achieved by a photosensitizer generating singlet oxygen (1O2) that, in turn, readily reacts with p-nitrophenol enzymatically produced under alkaline conditions. The photooxidation produces benzoquinone that is electrochemically reduced to hydroquinone, generating an amperometric response. The light-driven process could be easily separated from the background, thus making amperometric detection more reliable. The proposed method for detection of the toxocariasis antigen marker shows superior performances compared to other detection schemes with the same nanobodies and outperforms by at least two orders of magnitude the assays based on regular antibodies, thus suggesting new opportunities for electrochemical immunoassays of challenging low levels of antigens.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
Impact Factor: 6.32
DOI: 10.1021/ACS.ANALCHEM.1C02876
|
|
|
“Grazing-exit particle-induced X-ray emission analysis with extremely low background”. Tsuji K, Spolnik Z, Wagatsuma K, Van Grieken RE, Vis RD, Analytical chemistry 71, 5033 (1999). http://doi.org/10.1021/AC990568U
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC990568U
|
|
|
“Grazing exit electron probe microanalysis for surface and particle analysis”. Tsuji K, Wagatsuma K, Nullens R, Van Grieken RE, Analytical chemistry 71, 2497 (1999). http://doi.org/10.1021/AC990075P
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC990075P
|
|
|
“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)
|
|
|
“Characterization of a degraded cadmium yellow (CdS) pigment in an oil painting by means of synchrotron radiation based X-ray techniques”. van der Snickt G, Dik J, Cotte M, Janssens K, Jaroszewicz J, de Nolf W, Groenewegen J, van der Loeff L, Analytical chemistry 81, 2600 (2009). http://doi.org/10.1021/AC802518Z
Abstract: On several paintings of James Ensor (1860−1949), a gradual fading of originally bright yellow areas, painted with the pigment cadmium yellow (CdS), is observed. Additionally, in some areas exposed to light, the formation of small white-colored globules on top of the original paint surface is observed. In this paper the chemical transformation leading to the color change and to the formation of the globules is elucidated. Microscopic X-ray absorption near-edge spectroscopy (ì-XANES) experiments show that sulfur, originally present in sulfidic form (S2−), is oxidized during the transformation to the sulfate form (S6+). Upon formation (at or immediately below the surface), the highly soluble cadmium sulfate is assumed to be transported to the surface in solution and reprecipitates there, forming the whitish globules. The presence of cadmium sulfate (CdSO4·2H2O) and ammonium cadmium sulfate [(NH4)2Cd(SO4)2] at the surface is confirmed by microscopic X-ray diffraction measurements, where the latter salt is suspected to result from a secondary reaction of cadmium sulfate with ammonia. Measurements performed on cross sections reveal that the oxidation front has penetrated into the yellow paint down to ca. 1−2 ìm. The morphology and elemental distribution of the paint and degradation product were examined by means of scanning electron microscopy equipped with an energy-dispersive spectrometer (SEM-EDS) and synchrotron radiation based micro-X-ray fluorescence spectrometry (SR ì-XRF). In addition, ultraviolet-induced visible fluorescence photography (UIVFP) revealed itself to be a straightforward technique for documenting the occurrence of this specific kind of degradation on a macroscale by painting conservators.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 6.32
Times cited: 91
DOI: 10.1021/AC802518Z
|
|
|
“Combined use of synchrotron radiation based micro-X-ray fluorescence, micro-X-ray diffraction, micro-X-ray absorption near-edge, and micro-fourier transform infrared spectroscopies for revealing an alternative degradation pathway of the pigment cadmium yellow in a painting by Van Gogh”. van der Snickt G, Janssens K, Dik J, de Nolf W, Vanmeert F, Jaroszewicz J, Cotte M, Falkenberg G, Van der Loeff L, Analytical chemistry 84, 10221 (2012). http://doi.org/10.1021/AC3015627
Abstract: Over the past years a number of studies have described the instability of the pigment cadmium yellow (CdS). In a previous paper we have shown how cadmium sulfide on paintings by James Ensor oxidizes to CdSO4 center dot H2O. The degradation process gives rise to the fading of the bright yellow color and the formation of disfiguring white crystals that are present on the paint surface in approximately 50 mu m sized globular agglomerations. Here, we study cadmium yellow in the painting “Flowers in a blue vase” by Vincent van Gogh. This painting differs from the Ensor case in the fact that (a) a varnish was superimposed onto the degraded paint surface and (b) the CdS paint area is entirely covered with an opaque crust. The latter obscures the yellow color completely and thus presents a seemingly more advanced state of degradation. Analysis of a cross-sectioned and a crushed sample by combining scanning microscopic X-ray diffraction (mu-XRD), microscopic X-ray absorption near-edge spectroscopy (mu-XANES), microscopic X-ray fluorescence (mu-XRF) based chemical state mapping and scanning microscopic Fourier transform infrared (mu-FT-IR) spectrometry allowed unravelling the complex alteration pathway. Although no crystalline CdSO4 compounds were identified on the Van Gogh paint samples, we conclude that the observed degradation was initially caused by oxidation of the original CdS pigment, similar as for the previous Ensor case. However, due to the presence of an overlying varnish containing lead-based driers and oxalate ions, secondary reactions took place. In particular, it appears that upon the photoinduced oxidation of its sulfidic counterion, the Cd2+ ions reprecipitated at the paint/varnish interface after having formed a complex with oxalate ions that themselves are considered to be degradation products of the resin and/or oil in the varnish. The SO42- anions, for their part, found a suitable reaction partner in Pb2+ ions stemming from a dissolved lead-based siccative that was added to the varnish to promote its drying. The resulting opaque anglesite compound in the varnish, in combination with the underlying CdC2O4 layer at the paint/varnish interface, account for the orange-gray crust that is disfiguring the painting on a macroscopic level. In this way, the results presented in this paper demonstrate how, through a judicious combined use of several microanalytical methods with speciation capabilities, many new insights can be obtained from two minute, but highly complex and heterogeneous paint samples.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 6.32
Times cited: 59
DOI: 10.1021/AC3015627
|
|
|
“Enhancement effect in X-ray fluorescence analysis of environmental samples of medium thickness”. Van Dyck PM, Török SB, Van Grieken RE, Analytical chemistry 58, 1761 (1986). http://doi.org/10.1021/AC00121A036
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC00121A036
|
|
|
“Absorption correction via scattered radiation in energy-dispersive X-ray fluorescence analysis for samples of variable composition and thickness”. Van Dyck PM, Van Grieken RE, Analytical chemistry 52, 1859 (1980). http://doi.org/10.1021/AC50062A020
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC50062A020
|
|
|
“Effective sample weight from scatter peaks in energy-dispersive x-ray fluorescence”. van Espen P, Van 't dack L, Adams F, Van Grieken R, Analytical chemistry 51, 961 (1979). http://doi.org/10.1021/AC50043A042
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Chemometrics (Mitac 3)
DOI: 10.1021/AC50043A042
|
|
|
“Geometry errors in 14 MeV neutron activation analysis”. Van Grieken R, Speecke A, Hoste J, Journal of radioanalytical chemistry 13, 225 (1973). http://doi.org/10.1007/BF02514126
Abstract: The effects of inaccurate sample sizes and sample positioning on 14 MeV neutron activation analysis results are estimated for 30, 20 and 10 mm diameter targets. It appears that axial positioning is the most critical parameter and that using a larger tritium target will yield an overall improvement of the reproducibility.
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF02514126
|
|
|
“Simultaneous determination of silicon and phosphorus in cast iron by 14 MeV neutron activation analysis”. Van Grieken R, Speecke A, Hoste J, Journal of radioanalytical chemistry 6, 385 (1970). http://doi.org/10.1007/BF02513966
Abstract: A fast (10 min), non-destructive simultaneous determination of silicon and phosphorus in cast iron and steel by 14 MeV neutron activation was developed. The 1.78 MeV28Al activity (T=2.24 min) induced by the reaction28Si(n, p)28Al is counted on a NaI(Tl) detector. Two measurements are made to correct for the 1.81 MeV56Mn activity (T=2.58 hr) from the iron matrix. However,28Al is also produced via31P(n, α)28Al. By (n, 2n) reaction, phosphorus yields also30P (T=2.6 min), the 0.511 MeV annihilation radiation of which is counted by two opposite NaI(Tl) detectors in coincidence. Again, two successive coincidence measurements are carried out in order to take into account the53Fe activity (β+; T=8.9 min) from54Fe(n, 2n)53Fe. The28Al measurement is appropriately corrected via the computed phosphorus content. An oxygen flux monitor was used to normalize to the same flux. Nuclear interferences have been examined. Special attention has been paid to the presence of copper. The standard deviation for phosphorus being as high as ca. 0.09% P for a single determination, this technique can only be practical as an independent phosphorus analysis for high phosphorus cast irons. The precision on the28Al measurement is 5% relative for 0.2% Si and 2.5% above 1% Si.
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF02513966
|
|
|
“Spatial neutron flux distributions around A 14 MeV neutron generator”. Van Grieken R, Speecke A, Hoste J, Journal of radioanalytical chemistry 10, 95 (1972). http://doi.org/10.1007/BF02518771
Abstract: The neutron flux distribution in the vicinity of 30, 20 and 10 mm diameter targets is measured by irradiating concentric ring-type iron monitors at different distances from the target and counting the induced56Mn activity. Considering the many uncertainties, satisfactory agreement was found between theory and experiment.
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF02518771
|
|
|
“Chelex-100 ion-exchange filter membranes for preconcentration in x-ray-fluorescence analysis of water”. Van Grieken RE, Bresseleers CM, Vanderborght BM, Analytical chemistry 49, 1326 (1977). http://doi.org/10.1021/AC50017A011
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC50017A011
|
|
|
“Determination of platinum, palladium, and rhodium in automotive catalysts using high-energy secondary target X-ray fluorescence spectrometry”. van Meel K, Smekens A, Behets M, Kazandjian P, Van Grieken R, Analytical chemistry 79, 6383 (2007). http://doi.org/10.1021/AC070815R
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC070815R
|
|
|
“Quantitative characterization of individual particle surfaces by fractal analysis of scanning electron microscope images”. van Put A, Vertes A, Wegrzynek D, Treiger B, Van Grieken R, Fresenius' journal of analytical chemistry 350, 440 (1994). http://doi.org/10.1007/BF00321787
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF00321787
|
|
|
“The half-life of 28Al”. Van Schandevijl R, Van Grieken R, Hoste J, Journal of radioanalytical chemistry 9, 55 (1971). http://doi.org/10.1007/BF02514012
Abstract: The half-life of28Al was redetermined on aluminium samples of different origin. Three different counting techniques were applied. The availability of highly purified samples (up to 99.9999%), the use of very fast electronic counting equipment and a complete automatisation allowed a good precision to be obtained in the final result of 2.2405 min.
Keywords: A3 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1007/BF02514012
|
|
|
“Influence of axial and radial diffusion processes on the analytical performance of a glow discharge cell”. van Straaten M, Gijbels R, Vertes A, Analytical chemistry 64, 1855 (1992). http://doi.org/10.1021/ac00041a021
Keywords: A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
Impact Factor: 5.636
Times cited: 43
DOI: 10.1021/ac00041a021
|
|
|
“Spark-source mass-spectrometric sensitivity factors for elements in a graphite matrix”. Vanderborght B, Van Grieken R, Talanta : the international journal of pure and applied analytical chemistry 26, 461 (1979). http://doi.org/10.1016/0039-9140(79)80111-3
Abstract: Relative sensitivity factors for determination of 41 elements by spark-source mass-spectrometry have been measured. The samples were pressed into graphite electrodes and ionized with a radiofrequency spark. The mass spectra were recorded on a photoplate and the resulting data processed by a computer. Indium was used as standard and the relative sensitivity factors for both singly- and doubly-charged ions were determined with reference to the singly-charged indium ion, with an overall error of 30%. The mean analysis precision was 16%.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0039-9140(79)80111-3
|
|
|
“Enrichment of trace metals in water by adsorption on activated carbon”. Vanderborght BM, Van Grieken RE, Analytical chemistry 49, 311 (1977)
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
|
|
|
“Trace metal analysis of water containing humic substances by X-ray fluorescence”. Vanderborght BM, Van Grieken RE, International journal of environmental analytical chemistry 5, 221 (1978). http://doi.org/10.1080/03067317808071147
Abstract: Chelation by oxine followed by adsorption on activated carbon results in the efficient collection of many trace metal ions, independent of the trace metal concentration and of high alkali and alkaline earth ion abundances. Preconcentration factors around 10000 are often achieved. When this preconcentration procedure is combined with energy-dispersive X-ray fluorescence, accurate and precise analysis can be carried out, as was proven in several experiments. The technique can also be applied for the determination of divalent ions in natural waters containing up to 10 ppm of humic substances. Trivalent ions can quantitatively be collected from natural water provided suKicient activated carbon is added. Omitting the oxine chelation prior to the activated carbon adsorption step still results in collection of a sometimes important fraction of the trace metal ions from natural waters. This is related to organically bound or colloidal forms of the trace metals.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1080/03067317808071147
|
|
|
“Water analysis by spark-source mass-spectrometry after preconcentration on activated carbon”. Vanderborght BM, Van Grieken RE, Talanta : the international journal of pure and applied analytical chemistry 27, 417 (1980). http://doi.org/10.1016/0039-9140(80)80225-6
Abstract: For trace analyses of environmental waters, spark-source mass-spectrometry has been combined with a preconcentration procedure involving chelation of the dissolved trace elements with oxine and subsequent adsorption of the oxinates and naturally occurring organic and colloidal metal species onto activated carbon. The activated carbon is filtered off and ashed at low temperature. The residue is dissolved, an internal standard and pure graphite are added and, after drying, the electrodes are prepared. The photographically recorded mass spectrum is evaluated by a suitable computer routine. The error of the procedure is around 30%. While this preconcentration and analysis procedure is capable of measuring about 40 elements quantitatively, in practice 1025 trace elements are determined simultaneously above the 0.1-μg/l. detection limit, as is illustrated by analyses of drinking water, surface and ground water samples. Although a sophisticated technique, SSMS can be considered for regular panoramic survey analyses.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1016/0039-9140(80)80225-6
|
|
|
“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
|
|
|
“Transmission and reflection mode macroscopic x-ray powder diffraction imaging for the noninvasive visualization of paint degradation in still life paintings by Jan Davidsz. de Heem”. Vanmeert F, De Keyser N, van Loon A, Klaassen L, Noble P, Janssens K, Analytical chemistry 91, 7153 (2019). http://doi.org/10.1021/ACS.ANALCHEM.9B00328
Abstract: The use of noninvasive chemical imaging techniques is becoming more widespread for the study of cultural heritage artifacts. Recently a mobile instrument for macroscopic X-ray powder diffraction (MA-XRPD) scanning was developed, which is capable of visualizing the distribution of crystalline (pigment) phases in quasi-flat-painted artifacts. In this study, MA-XRPD is used in both transmission and reflection mode for the analysis of three 17th century still life paintings, two paintings by Jan Davidsz. de Heem (1606-1684) and one copy painting after De Heem by an unknown artist. MA-XRPD allowed to reveal and map the presence of in situ-formed alteration products. In the works examined, two rare lead arsenate minerals, schultenite (PbHAsO4) and mimetite (Pb-5(AsO4)(3)Cl), were encountered, both at and below the paint surface; they are considered to be degradation products of the pigments realgar (alpha-As4S4) and orpiment (As2S3). In transmission mode, the depletion of lead white, present in the (second) ground layer, could be seen, illustrating the intrusive nature of this degradation process. In reflection mode, several sulfate salts, palmierite (K2Pb(SO4)(2)), syngenite (K2Ca(SO4)(2)center dot H2O), and gypsum (CaSO4 center dot 2H(2)O), could be detected, in particular, at the (top) surface of the copy painting. Estimates for the information depth and sensitivity of both transmission and reflection mode MA-XRPD for various pigments have been made. The possibility of MA-XRPD to allow for noninvasive identification and visualization of alteration products is considered a significant advantage and unique feature of this method. MA-XRPD can thus provide highly relevant information for assessing the conservation state of artworks and could guide possible future restoration treatments.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 6.32
Times cited: 5
DOI: 10.1021/ACS.ANALCHEM.9B00328
|
|
|
“Macroscopic X-ray powder diffraction scanning, a new method for highly selective chemical imaging of works of art : instrument optimization”. Vanmeert F, de Nolf W, De Meyer S, Dik J, Janssens K, Analytical chemistry 90, 6436 (2018). http://doi.org/10.1021/ACS.ANALCHEM.8B00240
Abstract: In the past decade macroscopic X-ray fluorescence imaging (MA-XRF) has become established as a method for the noninvasive investigation of flat painted surfaces, yielding large scale elemental maps. MA-XRF is limited by a lack of specificity, only allowing for indirect pigment identification based on the simultaneous presence of chemical elements. The high specificity of X-ray powder diffraction (XRPD) mapping is already being exploited at synchrotron facilities for investigations at the (sub)microscopic scale, but the technique has not yet been employed using lab sources. In this paper we present the development of a novel MA-XRPD/XRF instrument based on a laboratory X-ray source. Several combinations of X-ray sources and area detectors are evaluated in terms of their spatial and angular resolution and their sensitivity. The highly specific imaging capability of the combined MA-XRPD/XRF instrument is demonstrated on a 15th/16th century illuminated manuscript directly revealing the distribution of a large number of inorganic pigments, including the uncommon yellow pigment massicot (o-PbO). The case study illustrates the wealth of new mapping information that can be obtained in a noninvasive manner using the laboratory MA-XRPD/XRF instrument.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 6.32
Times cited: 11
DOI: 10.1021/ACS.ANALCHEM.8B00240
|
|
|
“Macroscopic X-ray powder diffraction scanning : possibilities for quantitative and depth-selective parchment analysis”. Vanmeert F, de Nolf W, Dik J, Janssens K, Analytical chemistry 90, 6445 (2018). http://doi.org/10.1021/ACS.ANALCHEM.8B00241
Abstract: At or below the surface of painted works of art, valuable information is present that provides insights into an objects past, such as the artists technique and the creative process that was followed or its conservation history but also on its current state of preservation. Various noninvasive techniques have been developed over the past 2 decades that can probe this information either locally (via point analysis) or on a macroscopic scale (e.g., full-field imaging and raster scanning). Recently macroscopic X-ray powder diffraction (MA-XRPD) mapping using laboratory X-ray sources was developed. This method can visualize highly specific chemical distributions at the macroscale (dm(2)). In this work we demonstrate the synergy between the quantitative aspects of powder diffraction and the noninvasive scanning capability of MA-XRPD highlighting the potential of the method to reveal new types of information. Quantitative data derived from a 15th/16th century illuminated sheet of parchment revealed three lead white pigments with different hydrocerussite-cerussite compositions in specific pictorial elements, while quantification analysis of impurities in the blue azurite pigment revealed two distinct azurite types: one rich in barite and one in quartz. Furthermore, on the same artifact, the depth-selective possibilities of the method that stem from an exploitation of the shift of the measured diffraction peaks with respect to reference data are highlighted. The influence of different experimental parameters on the depth-selective analysis results is briefly discussed. Promising stratigraphic information could be obtained, even though the analysis is hampered by not completely understood variations in the unit cell dimensions of the crystalline pigment phases.
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Impact Factor: 6.32
Times cited: 6
DOI: 10.1021/ACS.ANALCHEM.8B00241
|
|
|
“Embedded ion exchange beads as standards for laser microprobe mass analysis of biological specimens”. Verbueken AH, Van Grieken RE, Paulus GJ, De Bruijn WC, Analytical chemistry 56, 1362 (1984). http://doi.org/10.1021/AC00272A036
Keywords: A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
DOI: 10.1021/AC00272A036
|
|