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Author van der Snickt, G.; Dik, J.; Cotte, M.; Janssens, K.; Jaroszewicz, J.; de Nolf, W.; Groenewegen, J.; van der Loeff, L. doi  openurl
  Title Characterization of a degraded cadmium yellow (CdS) pigment in an oil painting by means of synchrotron radiation based X-ray techniques Type A1 Journal article
  Year 2009 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 81 Issue 7 Pages 2600-2610  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000264759400025 Publication Date 2009-03-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 91 Open Access  
  Notes Approved (down) Most recent IF: 6.32; 2009 IF: 5.214  
  Call Number UA @ admin @ c:irua:76415 Serial 5501  
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Author Dik, J.; Janssens, K.; van der Snickt, G.; van der Loeff, L.; Rickers, K.; Cotte, M. doi  openurl
  Title Visualization of a lost painting by Vincent van Gogh using synchrotron radiation based X-ray fluorescence elemental mapping Type A1 Journal article
  Year 2008 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 80 Issue 16 Pages 6436-6442  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Vincent van Gogh (1853−1890), one of the founding fathers of modern painting, is best known for his vivid colors, his vibrant painting style, and his short but highly productive career. His productivity is even higher than generally realized, as many of his known paintings cover a previous composition. This is thought to be the case in one-third of his early period paintings. Van Gogh would often reuse the canvas of an abandoned painting and paint a new or modified composition on top. These hidden paintings offer a unique and intimate insight into the genesis of his works. Yet, current museum-based imaging tools are unable to properly visualize many of these hidden images. We present the first-time use of synchrotron radiation based X-ray fluorescence mapping, applied to visualize a womans head hidden under the work Patch of Grass by Van Gogh. We recorded decimeter-scale, X-ray fluorescence intensity maps, reflecting the distribution of specific elements in the paint layers. In doing so we succeeded in visualizing the hidden face with unprecedented detail. In particular, the distribution of Hg and Sb in the red and light tones, respectively, enabled an approximate color reconstruction of the flesh tones. This reconstruction proved to be the missing link for the comparison of the hidden face with Van Goghs known paintings. Our approach literally opens up new vistas in the nondestructive study of hidden paint layers, which applies to the oeuvre of Van Gogh in particular and to old master paintings in general.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000258448100039 Publication Date 2008-07-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 178 Open Access  
  Notes Approved (down) Most recent IF: 6.32; 2008 IF: 5.712  
  Call Number UA @ admin @ c:irua:74466 Serial 5906  
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Author Bulska, E.; Wysocka, I.A.; Wierzbicka, M.H.; Proost, K.; Janssens, K.; Falkenberg, G. doi  openurl
  Title In vivo investigation of the distribution and the local speciation of selenium in Allium cepa L. by means of microscopic X-ray absorption near-edge structure spectroscopy and confocal microscopic X-ray fluorescence analysis Type A1 Journal article
  Year 2006 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 78 Issue 22 Pages 7616-7624  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract  
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  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000242021400003 Publication Date 2006-10-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 56 Open Access  
  Notes Approved (down) Most recent IF: 6.32; 2006 IF: 5.646  
  Call Number UA @ admin @ c:irua:60714 Serial 5659  
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Author Kempenaers, L.; Janssens, K.; Vincze, L.; Vekemans, B.; Somogyi, A.; Drakopoulos, M.; Simionovici, A.S.; Adams, F. doi  openurl
  Title A Monte Carlo model for studying the microheterogeneity of trace elements in reference materials by means of synchrotron microscopic X-ray fluorescence Type A1 Journal article
  Year 2002 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 74 Issue 19 Pages 5017-5026  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000178418100031 Publication Date 2002-09-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 21 Open Access  
  Notes Approved (down) Most recent IF: 6.32; 2002 IF: 5.094  
  Call Number UA @ admin @ c:irua:39871 Serial 5734  
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Author Vincze, L.; Somogyi, A.; Osán, J.; Vekemans, B.; Török, S.; Janssens, K.; Adams, F. doi  openurl
  Title Quantitative trace element analysis of individual fly ash particles by means of X-ray microfluorescence Type A1 Journal article
  Year 2002 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 74 Issue Pages 1128-1135  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000174187900032 Publication Date 2006-06-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 44 Open Access  
  Notes Approved (down) Most recent IF: 6.32; 2002 IF: 5.094  
  Call Number UA @ admin @ c:irua:38377 Serial 5796  
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Author Rahemi, V.; Sarmadian, N.; Anaf, W.; Janssens, K.; Lamoen, D.; Partoens, B.; De Wael, K. pdf  url
doi  openurl
  Title Unique opto-electronic structure and photo reduction properties of sulfur doped lead chromates explaining their instability in paintings Type A1 Journal article
  Year 2017 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 89 Issue 89 Pages 3326-3334  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Washington, D.C. Editor  
  Language Wos 000397478300015 Publication Date 2017-02-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 7 Open Access OpenAccess  
  Notes ; The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government, department EWI. The BOF-GOA action SOLARPAINT of the University of Antwerp Research Council is acknowledged for financial support. W.A. acknowledges support from BELSPO project S2-ART. Dr. L. Monico and Dr. C. Miliani (ISTM, Perugia) are gratefully acknowledged for helpful discussions and for providing some of the initial batches of the materials studied. ; Approved (down) Most recent IF: 6.32  
  Call Number UA @ lucian @ c:irua:140886 Serial 4451  
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Author Sleegers, N.; van Nuijs, A.L.N.; van den Berg, M.; De Wael, K. url  doi
openurl 
  Title Cephalosporin antibiotics : electrochemical fingerprints and core structure reactions investigated by LC-MSMS Type A1 Journal article
  Year 2019 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 91 Issue 3 Pages 2035-2041  
  Keywords A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre  
  Abstract Electrochemistry and exploiting electrochemical fingerprints is a potent approach to address newly emerging surveillance needs, for instance for antibiotics. However, a comprehensive insight in the electrochemical oxidation behaviour and mechanism is re-quired for this sensing strategy. To address the lack in knowledge of the voltammetric behaviour of the cephalosporins antibiotics, a selection of cephalosporin antibiotics and two main intermediates were subjected to an electrochemical study of their redox behaviour by means of pulsed voltammetric techniques and small-scale electrolysis combined with HPLC-MS/MS analyses. Sur-prisingly, the detected oxidation products did not fit the earlier suggested oxidation of the sulfur group to the corresponding sul-foxide. The influence of different side chains, both at the three and the seven position of the β-lactam core structure on the elec-trochemical fingerprint were investigated. Additional oxidation signals at lower potentials were elucidated and linked to different side chains. These signals were further exploited to allow simultaneous detection of different cephalosporins in one voltammetric sweep. These fundamental insights can become the building blocks for an new on-site screening method.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000458220300055 Publication Date 2019-01-03  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 6 Open Access  
  Notes ; The authors acknowledge financial support from the Fund for Scientific Research (FWO) Flanders, Grant 1S 37658 17N. ; Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:156046 Serial 5497  
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Author Cagno, S.; Brede, D.A.; Nuyts, G.; Vanmeert, F.; Pacureanu, A.; Tucoulou, R.; Cloetens, P.; Falkenberg, G.; Janssens, K.; Salbu, B.; Lind, O.C. url  doi
openurl 
  Title Combined computed nanotomography and nanoscopic x-ray fluorescence imaging of cobalt nanoparticles in caenorhabditis elegans Type A1 Journal article
  Year 2017 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 89 Issue 21 Pages 11435-11442  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Synchrotron radiation phase-contrast computed nanotomography (nano-CT) and two-and three-dimensional (2D and 3D) nanoscopic X-ray fluorescence (nano-XRF) were used to investigate the internal distribution of engineered-cobalt nanoparticles (Co NPs) in exposed individuals of the nematode Caenorhabditis elegans. Whole-nematodes and selected tissues and organs were 3D-rendered: anatomical 3D renderings with 50 nm voxel size enabled the visualization of spherical nanoparticle aggregates. with size tip to 200 nm within intact C. elegans. A 20 X 37 nm(2) high-brilliance beam was employed to obtain XRF elemental distribution maps of entire nematodes or anatomical details such as embryos, which could be compared with the CT data, These maps showed Co NPs to be predominantly present within the intestine and the epithelium, and they were not colocalized with Zn granules found in the lysosonie-containing vesicles or Fe agglomerates in the intestine. Iterated XRF scanning of a specimen at 0 degrees and 90 degrees angles suggested that NP aggregates were translocated into tissues outside of the intestinal lumen. Virtual-slicing by means of 2D XRF tomography, combined with holotomography, indicated presumable presence of individual NP aggregates inside the uterus and within embryos.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000414887000041 Publication Date 2017-10-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 13 Open Access  
  Notes ; This study has been funded by the Norwegian Research Council through its Centre of Excellence (CoE) funding scheme (Project 223268/F50). We gratefully acknowledge ESRF and DESY for granting beamtime and Karl Andreas Jensen for performing ICPMS analysis. We thank Erica Maremonti for supplying the phase-contrast image used in Figure ^1A. ; Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:147383 Serial 5520  
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Author Florea, A.; Schram, J.; De Jong, M.; Eliaerts, J.; Van Durme, F.; Kaur, B.; Samyn, N.; De Wael, K. url  doi
openurl 
  Title Electrochemical strategies for adulterated heroin samples Type A1 Journal article
  Year 2019 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 91 Issue 12 Pages 7920-7928  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Electrochemical strategies to selectively detect heroin in street samples without the use of complicated electrode modifications were developed for the first time. For this purpose, heroin, mixing agents (adulterants, cutting agent, and impurities), and their binary mixtures were subjected to square wave voltammetry measurements at bare graphite electrodes at pH 7.0 and pH 12.0, in order to elucidate the unique electrochemical fingerprint of heroin and mixing agents as well as possible interferences or reciprocal influences. Adjusting the pH from pH 7.0 to pH 12.0 allowed a more accurate detection of heroin in the presence of most common mixing agents. Furthermore, the benefit of introducing a preconditioning step prior to running square wave voltammetry on the electrochemical fingerprint enrichment was explored. Mixtures of heroin with other drugs (cocaine, 3,4-methylenedioxymethamphetamine, and morphine) were also tested to explore the possibility of their discrimination and simultaneous detection. The feasibility of the proposed electrochemical strategies was tested on realistic heroin street samples from forensic cases, showing promising results for fast, on-site detection tools of drugs of abuse.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000472682000056 Publication Date 2019-05-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 2 Open Access  
  Notes ; This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 753223 Narcoreader. The authors also acknowledge IOF (UAntwerp) and Belspo for financial support. ; Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:160061 Serial 5596  
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Author Morales-Yanez, F.; Trashin, S.; Hermy, M.; Sariego, I.; Polman, K.; Muyldermans, S.; De Wael, K. url  doi
openurl 
  Title Fast one-step ultrasensitive detection of toxocara canis antigens by a nanobody-based electrochemical magnetosensor Type A1 Journal article
  Year 2019 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 91 Issue 18 Pages 11582-11588  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Human toxocariasis (HT) is a cosmopolitan zoonotic disease caused by the migration of the larval stage of the roundworm Toxocara canis. Current HT diagnostic methods do not discriminate between active and past infections. Here, we present a method to quantify Toxocara excretory/secretory antigen, aiming to identify active cases of HT. High specificity is achieved by employing nanobodies (Nbs), single domain antigen binding fragments from camelid heavy chain-only antibodies. High sensitivity is obtained by the design of an electrochemical magnetosensor with an amperometric read-out. Reliable detection of TES antigen at 10 and 30 pg/mL level was demonstrated in phosphate buffered saline and serum, respectively. Moreover, the assay showed no cross-reactivity with other nematode antigens. To our knowledge, this is the most sensitive method to quantify the TES antigen so far. It also has great potential to develop point of care diagnostic systems in other conditions where high sensitivity and specificity are required.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000487156900016 Publication Date 2019-08-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 2 Open Access  
  Notes ; This project was funded by the Fonds Wetenschappelijk Onderzoek-Vlaanderen (FWO-Flanders, Project G.0189.13N) and BOF UAntwerp. The authors acknowledge Prof. Pierre Dorny (Institute of Tropical Medicine Antwerp) and Dr. Beatrice Nickel (Swiss Institute of Tropical Medicine) for providing the antigens needed for the cross-reactivity experiments. ; Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:163784 Serial 5621  
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Author De Jong, M.; Florea, A.; de Vries, A.-M.; van Nuijs, A.L.N.; Covaci, A.; Van Durme, F.; Martins, J.C.; Samyn, N.; De Wael, K. url  doi
openurl 
  Title Levamisole : a common adulterant in cocaine street samples hindering electrochemical detection of cocaine Type A1 Journal article
  Year 2018 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 90 Issue 8 Pages 5290-5297  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre  
  Abstract The present work investigates the electrochemical determination of cocaine in the presence of levamisole, one of the most common adulterants found in cocaine street samples. Levamisole misleads cocaine color tests, giving a blue color (positive test) even in the absence of cocaine. Moreover, the electrochemical detection of cocaine is also affected by the presence of levamisole, with a suppression of the oxidation signal of cocaine. When levamisole is present in the sample in ratios higher than 1:1, the cocaine signal is no longer detected, thus leading to false negative results. Mass spectrometry and nuclear magnetic resonance were used to investigate if the signal suppression is due to the formation of a complex between cocaine and levamisole in bulk solution. Strategies to eliminate this suppressing effect are further suggested in this manuscript. In a first approach, the increase of the pH of the sample solution from pH 7 to pH 12 allowed the voltammetric determination of cocaine in the presence of levamisole in a concentration range from 10 to 5000 μM at nonmodified graphite disposable electrodes with a detection limit of 5 μM. In a second approach, the graphite electrode was cathodically pretreated, resulting in the presence of oxidation peaks of both cocaine and levamisole, with a detection limit for cocaine of 3 μM over the linear range of concentrations from 10 to 2500 μM. Both these strategies have been successfully applied for the simultaneous detection of cocaine and levamisole in three street samples on unmodified graphite disposable electrodes.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000430512200049 Publication Date 2018-02-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 8 Open Access  
  Notes ; This project has received funding from the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement No. 753223 Narcoreader. This work was also supported by BR/314/PI/ APTADRU Project and IOF-SBO (UAntwerp). Alexander van Nuijs acknowledges the Research Foundation-Flanders (FWO) for his postdoctoral fellowship. ; Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:149528 Serial 5693  
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Author Vanmeert, F.; de Nolf, W.; De Meyer, S.; Dik, J.; Janssens, K. url  doi
openurl 
  Title Macroscopic X-ray powder diffraction scanning, a new method for highly selective chemical imaging of works of art : instrument optimization Type A1 Journal article
  Year 2018 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 90 Issue 11 Pages 6436-6444  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  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.  
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  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000434893200019 Publication Date 2018-04-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 11 Open Access  
  Notes ; The authors thank the persons involved at Incoatec GmbH, imXPAD SAS and Dectris Ltd. for loaning us some of their products over the past years. We acknowledge financial support from BELSPO (Brussels) S2-ART, the NWO (The Hague) Science4Arts “ReVisRembrandt” Project and GOA Project Solarpaint (University of Antwerp Research Council). Photo Copyright Geert Van der Snickt, 2008 for the photograph of the illuminated manuscript in the TOC graphic. ; Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:151993 Serial 5701  
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Author Vanmeert, F.; de Nolf, W.; Dik, J.; Janssens, K. url  doi
openurl 
  Title Macroscopic X-ray powder diffraction scanning : possibilities for quantitative and depth-selective parchment analysis Type A1 Journal article
  Year 2018 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 90 Issue 11 Pages 6445-6452  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  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.  
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  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000434893200020 Publication Date 2018-04-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 6 Open Access  
  Notes ; The authors thank Incoatec GmbH for giving us the opportunity to test the I mu S Cu X-ray source. We acknowledge financial support from BELSPO (Brussels) S2-ART, the NWO (The Hague) Science4Arts “ReVisRembrandt” project, and GOA Project Solarpaint (University of Antwerp Research Council). Photo Copyright Geert Van der Snickt, 2008 for the photograph of the illuminated manuscript in the TOC graphic. ; Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:151994 Serial 5702  
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Author Neven, L.; Thiruvottriyur Shanmugam, S.; Rahemi, V.; Trashin, S.; Sleegers, N.; Carrion, E.N.; Gorun, S.M.; De Wael, K. pdf  url
doi  openurl
  Title Optimized photoelectrochemical detection of essential drugs bearing phenolic groups Type A1 Journal article
  Year 2019 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 91 Issue 15 Pages 9962-9969  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The World Health Organization (WHO) model “List of Essential Medicines” includes among indispensable medicines antibacterials and pain and migraine relievers. Monitoring their concentration in the environment, while challenging, is important in the context of antibiotic resistance as well as their production of highly toxic compounds via hydrolysis. Traditional detection methods such as high-performance liquid chromatography (HPLC) or LC combined with tandem mass spectrometry or UV-vis spectroscopy are time-consuming, have a high cost, require skilled operators and are difficult to adapt for field operations. In contrast, (electrochemical) sensors have elicited interest because of their rapid response, high selectivity, and sensitivity as well as potential for on-site detection. Previously, we reported a novel sensor system based on a type II photosensitizer, which combines the advantages of enzymatic sensors (high sensitivity) and photoelectrochemical sensors (easy baseline subtraction). Under red-light illumination, the photosensitizer produces singlet oxygen which oxidizes phenolic compounds present in the sample. The subsequent reduction of the oxidized phenolic compounds at the electrode surface gives rise to a quantifiable photocurrent and leads to the generation of a redox cycle. Herein we report the optimization in terms of pH and applied potential of the photoelectrochemical detection of the hydrolysis product of paracetamol, i.e., 4-aminophenol (4-AP), and two antibacterials, namely, cefadroxil (CFD, beta-lactam antibiotic) and doxycycline (DXC, tetracycline antibiotic). The optimized conditions resulted in a detection limit of 0.2 mu mol L-1 for DXC, but in a 10 times higher sensitivity, 20 nmol L-1, for CFD. An even higher sensitivity, 7 nmol L-1, was noted for 4-AP.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000480499200086 Publication Date 2019-06-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 2 Open Access  
  Notes ; FWO and UA-BOF are acknowledged for financial support. The Center for Functional Materials of Seton Hall University is thanked for support (S.M.G. and E.N.C.). Joren Van Loon is thanked for the graphical abstract. This research was supported by the medium scale research infrastructure funding Hercules funding (SEM). ; Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:161831 Serial 5763  
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Author Alvarez-Martin, A.; Cleland, T.P.; Kavich, G.M.; Janssens, K.; Newsome, G.A. pdf  doi
openurl 
  Title Rapid evaluation of the debromination mechanism of eosin in oil paint by direct analysis in real time and direct infusion-electrospray ionization mass spectrometry Type A1 Journal article
  Year 2019 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 91 Issue 16 Pages 10856-10863  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Eosin is a synthetic organic colorant prone to fading under the influence of light. On the basis of the growing interest in the understanding of the discoloration mechanism of eosin-based lakes, this study compares the ability of two ultrafast and ultrasensitive mass spectrometry techniques to detect eosin derivatives in complex matrices, such as oil media without the use of conventional separation columns or additional sample preparation protocols. Direct analysis in real time mass spectrometry (DART-MS) and direct infusion electrospray ionization mass spectrometry (DI-ESI-MS) were used to characterize the degradation pathway of eosin in oil media. The analysis protocols developed in this study are applied to discern the degradation mechanism of the lake pigment eosin (comprising the molecule per se complexed to an inorganic substrate) dispersed in linseed oil to create an oil paint. The analysis of oil paints by high resolution MS without an extraction methodology that modifies the system chemistry allowed us to identify the degradation forms without causing any additional fragmentation. Both techniques revealed the primary photodegradation pathway of eosin in linseed oil, and DI-ESI-MS provided additional information on the native conformation of the lake.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000482545300069 Publication Date 2019-07-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 3 Open Access  
  Notes ; The authors would like to acknowledge the SolarPaint project (GOA program, Antwerp University Research Council) and Smithsonian Institution for financial support. ; Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:162879 Serial 5800  
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Author De Jong, M.; Florea, A.; Eliaerts, J.; Van Durme, F.; Samyn, N.; De Wael, K. url  doi
openurl 
  Title Tackling poor specificity of cocaine color tests by electrochemical strategies Type A1 Journal article
  Year 2018 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 90 Issue 11 Pages 6811-6819  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract This paper presents electrochemical strategies for the fast screening of cocaine and most common cutting agents found in seized drug samples. First, a study on the performance of Scott color tests on cocaine and a wide range of cutting agents is described. The cutting agents causing false positive or false negative results when in mixture with cocaine are identified. To overcome the lack of specificity of color tests, we further propose a fast screening strategy by means of square wave voltammetry on disposable graphite screen printed electrodes, which reveals the unique fingerprint of cocaine and cutting agents. By employing a forward and backward scan and by a dual pH strategy, we enrich the electrochemical fingerprint and enable the simultaneous detection of cocaine and cutting agents. The effectiveness of the developed strategies was tested for the detection of cocaine in seized cocaine samples and compared with the color tests. Moreover, we prove the usefulness of square wave voltammetry for predicting possible interfering agents in color tests, based on the reduction peak of cobalt thiocyanate. The developed electrochemical strategies allow for a quick screening of seized cocaine samples resulting in a selective identification of drugs and cutting agents.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000434893200066 Publication Date 2018-05-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 7 Open Access  
  Notes ; This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 753223 Narcoreader. This work was also supported by Grants BR/314 /PI/APTADRU and IOF-SBO. ; Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:151316 Serial 5867  
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Author Vanmeert, F.; De Keyser, N.; van Loon, A.; Klaassen, L.; Noble, P.; Janssens, K. url  doi
openurl 
  Title 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 Type A1 Journal article
  Year 2019 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 91 Issue 11 Pages 7153-7161  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000470793800031 Publication Date 2019-05-10  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 5 Open Access  
  Notes ; The authors acknowledge financial support from BELSPO (Brussels) S2-ART and METOX projects, the NWO (The Hague) Science4Arts “ReVisRembrandt” project, and the GOA Project Solarpaint (University of Antwerp Research Council). The authors thank the Rijksmuseum, the Royal Museum of Fine Arts Antwerp, and their staff for the collaborations. ; Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:160245 Serial 5882  
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Author De Jong, M.; Sleegers, N.; Florea, A.; Van Loon, J.; van Nuijs, A.L.N.; Samyn, N.; De Wael, K. url  doi
openurl 
  Title Unraveling the mechanisms behind the complete suppression of cocaine electrochemical signals by chlorpromazine, promethazine, procaine, and dextromethorphan Type A1 Journal article
  Year 2019 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 91 Issue 24 Pages 15453-15460  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre; Product development  
  Abstract The present work investigates the challenges accompanied by the electrochemical cocaine detection in physiological conditions (pH 7) in the presence of chlorpromazine, promethazine, procaine, and dextromethorphan, frequently used cutting agents in cocaine street samples. The problem translates into the absence of the cocaine oxidation signal (signal suppression) when in a mixture with one of these compounds, leading to false negative results. Although a solution to this problem was provided through earlier experiments of our group, the mechanisms behind the suppression are now fundamentally investigated via electrochemical and liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) strategies. The latter was used to confirm the passivation of the electrodes due to their interaction with promethazine and chlorpromazine. Electron transfer mechanisms were further identified via linear sweep voltammetry. Next, adsorption experiments were performed on the graphite screen printed electrodes both with and without potential assistance in order to confirm if the suppression of the cocaine signals is due to passivation induced by the cutting agents or their oxidized products. The proposed strategies allowed us to identify the mechanisms of cocaine suppression for each cutting agent mentioned. Suppression due to procaine and dextromethorphan is caused by fouling of the electrode surface by their oxidized forms, while for chlorpromazine and promethazine the suppression of the cocaine signal is related to the strong adsorption of these (nonoxidized) cutting agents onto the graphite electrode surface. These findings provide fundamental insights in possible suppression and other interfering mechanisms using electrochemistry in general not only in the drug detection sector.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000503910600018 Publication Date 2019-11-14  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited Open Access  
  Notes ; The authors acknowledge financial support from IOF-SBO/POC (UAntwerp) and the Fund for Scientific Research (FWO) Flanders, Grant 1S 37658 17N. ; Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:165727 Serial 5887  
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Author Ayalew, E.; Janssens, K.; De Wael, K. url  doi
openurl 
  Title Unraveling the reactivity of minium towards bicarbonate and the role of lead oxides therein Type A1 Journal article
  Year 2016 Publication Analytical chemistry Abbreviated Journal Anal Chem  
  Volume 88 Issue 3 Pages 1564-1569  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract Understanding the reactivity of (semiconductor) pigments provides vital information on how to improve conservation strategies for works of art in order to avoid rapid degradation of the pigments. This study focuses on the photoactivity of minium (Pb3O4), a semiconductor pigment, that gives rise to strong discoloration phenomena upon exposure to various environmental conditions. To demonstrate its photoactivity, an electrochemical setup with minium-modified graphite electrode (C|Pb3O4) was used. It is confirmed that minium is a p-type semiconductor which is photoactive during illumination and becomes inactive in the dark. Raman measurements confirm the formation of the degradation products. The photoactivity of a semiconductor pigment is partly defined by the presence of lead oxide (PbO) impurities; these introduce new states in the original band gap. It will be experi-mentally evidenced that the presence of PbO particles in minium leads to an upward shift of the valence band that reduces the band gap. Thus, upon photoexcitation, the electron/hole separation is more easily initialized. The PbO/Pb3O4 composite electrodes demonstrate a higher reductive photocurrent compared to the photocurrent registered at pure PbO or Pb3O4 modified electrodes. Upon exposure to light with energy close to and above the band gap, electrons are excited from the valence band to the conduction band to initialize the reduction of Pb(IV) to Pb(II), resulting in the initial formation of PbO. However in the presence of bicarbonate ions, a significantly higher photoreduction current is recorded since the PbO reacts further to form hydrocerussite. Therefore the presence of bicarbonates in the environment stimulates the photodecomposition process of minium and plays an important role in the degradation process.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000369471100014 Publication Date 2015-12-31  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited 9 Open Access  
  Notes ; The authors acknowledge Sanne Aerts from the Laboratory of Adsorption and Catalysis (LADCA) of the University of Antwerp for her help with the UV-vis-DR. Financial support from the SOLARPAINT BOF-GOA project (University of Antwerp Research Council) is acknowledged. The authors are also indebted to F. Vanmeert for performing the XRD measurements. ; Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:129963 Serial 5888  
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Author Sleegers, N.; van Nuijs, A.L.N.; van den Berg, M.; De Wael, K. pdf  doi
openurl 
  Title Electrochemistry of intact versus degraded cephalosporin antibiotics facilitated by LC–MS analysis Type A1 Journal article
  Year 2021 Publication Analytical Chemistry Abbreviated Journal Anal Chem  
  Volume 93 Issue 4 Pages 2394-2402  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre  
  Abstract The electrochemical detection of cephalosporins is a promising approach for the monitoring of cephalosporin levels in process waters. However, this class of antibiotics, like penicillins, is composed of chemically active molecules and susceptible to hydrolysis and aminolysis of the four membered β-lactam ring present. In order to develop a smart monitoring strategy for cephalosporins, the influence of degradation (hydrolysis and aminolysis) on the electrochemical fingerprint has to be taken into account. Therefore, an investigation was carried out to understand the changes of the voltammetric fingerprints upon acidic and alkaline degradation. Changes in fingerprints were correlated to the degradation pathways through the combination of square wave voltammetry and liquid chromatography quadrupole time-of-flight analysis. The characteristic electrochemical signals of the β-lactam ring disappeared upon hydrolysis. Additional oxidation signals that appeared after degradation were elucidated and linked to different degradation products, and therefore, enrich the voltammetric fingerprints with information of the state of the cephalosporins. The applicability of the electrochemical monitoring system was explored by the analysis of the intact and degraded industrial process waters containing the key intermediate 7-aminodeacetoxycephalosporanic acid (7-ADCA). Clearly, the intact process samples exhibited the expected core signals of 7-ADCA and could be quantified, while the degraded samples only showed the newly formed degradation products.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000618089100063 Publication Date 2021-01-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited Open Access Not_Open_Access  
  Notes Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:176206 Serial 7864  
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Author Alvarez-Martin, A.; Newsome, G.A.; Janssens, K. pdf  url
doi  openurl
  Title High-resolution mass spectrometry and nontraditional mass defect analysis of brominated historical pigments Type A1 Journal article
  Year 2021 Publication Analytical Chemistry Abbreviated Journal Anal Chem  
  Volume 93 Issue 44 Pages 14851-14858  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp X-ray Imaging and Spectroscopy (AXIS)  
  Abstract The implementation of high-resolution mass spectrometry systems offers new possibilities for the analysis of complex art samples such as historical oil paintings. However, these multicomponent systems generate large and complex data sets that require advanced visualization tools to aid interpretation, especially when no chromatographic separation is performed. In the context of this research, it was crucial to propose a data analysis tool to identify the products generated during the synthesis, drying, and aging of historical pigments. This study reports for the first time a nontraditional mass defect analysis of oil paint samples containing a fugitive brominated-organic pigment, eosin or geranium lake, by using direct infusion electrospray ionization in combination with a high-resolution Orbitrap mass spectrometer. The use of nontraditional Kendrick mass defect plots is presented in this study as a processing and visualization tool to recognize brominated species based on their specific mass defect and isotope pattern. The results demonstrate that this approach could provide valuable molecular compositional information on the degradation pathways of this pigment. We anticipate that mass defect analysis will become highly relevant in future degradation studies of many more historical organic pigments.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000718171600037 Publication Date 2021-10-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited Open Access OpenAccess  
  Notes Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:182347 Serial 8038  
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Author Trashin, S.; Morales-Yánez, F.; Thiruvottriyur Shanmugam, S.; Paredis, L.; Carrión, E.N.; Sariego, I.; Muyldermans, S.; Polman, K.; Gorun, S.M.; De Wael, K. pdf  url
doi  openurl
  Title Nanobody-based immunosensor detection enhanced by photocatalytic-electrochemical redox cycling Type A1 Journal article
  Year 2021 Publication Analytical Chemistry Abbreviated Journal Anal Chem  
  Volume 93 Issue 40 Pages 13606-13614  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)  
  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.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000708550500025 Publication Date 2021-09-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2700; 5206-882x ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.32 Times cited Open Access OpenAccess  
  Notes Approved (down) Most recent IF: 6.32  
  Call Number UA @ admin @ c:irua:181795 Serial 8290  
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Author Baez, J.F.; Compton, M.; Chahrati, S.; Cánovas, R.; Blondeau, P.; Andrade, F.J. doi  openurl
  Title Controlling the mixed potential of polyelectrolyte-coated platinum electrodes for the potentiometric detection of hydrogen peroxide Type A1 Journal article
  Year 2020 Publication Analytica Chimica Acta Abbreviated Journal Anal Chim Acta  
  Volume 1097 Issue Pages 204-213  
  Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The use of a Pt electrode coated with a layer of Nafion has been described in previous works as an attractive way to perform the potentiometric detection of hydrogen peroxide. Despite of the attractive features of this approach, the nature of the non-Nernstian response of this system was not properly addressed. In this work, using a mixed potential model, the open circuit potential of the Pt electrode is shown to be under kinetic control of the oxygen reduction reaction (ORR). It is proposed that hydrogen peroxide acts as an oxygenated species that blocks free sites on the Pt surface, interfering with the ORR. Therefore, the effect of the polyelectrolyte coating can be understood in terms of the modulation of the factors that affects the kinetics of the ORR, such as an increase of the H+ concentration, minimization of the effect of the spectator species, etc. Because of the complexity and the lack of models that accurately describe systems with practical applications, this work is not intended to provide a mechanistic but rather a phenomenological view on problem. A general framework to understand the factors that affect the potentiometric response is provided. Experimental evidence showing that the use of polyelectrolyte coatings are a powerful way to control the mixed potential open new ways for the development of robust and simple potentiometric sensors.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos Publication Date 2019-11-13  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-2670; 1873-4324 ISBN Additional Links UA library record  
  Impact Factor 6.2 Times cited Open Access  
  Notes Approved (down) Most recent IF: 6.2; 2020 IF: 4.95  
  Call Number UA @ admin @ c:irua:184381 Serial 7731  
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Author Pauwels, D.; Hereijgers, J.; Verhulst, K.; De Wael, K.; Breugelmans, T. pdf  url
doi  openurl
  Title Investigation of the electrosynthetic pathway of the aldol condensation of acetone Type A1 Journal article
  Year 2016 Publication Chemical engineering journal Abbreviated Journal Chem Eng J  
  Volume 289 Issue Pages 554-561  
  Keywords A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Applied Electrochemistry & Catalysis (ELCAT)  
  Abstract The potential-controlled electrochemical aldol condensation of acetone to diacetone alcohol in a standard batch electrolysis set-up was studied in this work. It is confirmed that the reaction proceeds at the cathode and that, contrary to what is mentioned in earlier literature, water in the electrolyte has a disadvantageous effect on the reaction. Similar to the chemical reaction, the electrochemical reaction reaches a maximum yield when the equilibrium is reached. Separating the anode and cathode prevents cross-over and degradation of products, leading to a higher yield. Starting with pure acetone and support electrolyte, it was possible to obtain a diacetone alcohol concentration of 15 m% after two hours electrolysis in a divided set-up with a platinum electrode at -2.5 V. The concentration gradient throughout the electrolysis follows an exponential curve up to its equilibrium concentration.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000371559900061 Publication Date 2016-01-13  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1385-8947; 1873-3212 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.216 Times cited 6 Open Access  
  Notes ; ; Approved (down) Most recent IF: 6.216  
  Call Number UA @ admin @ c:irua:130396 Serial 5675  
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Author Blommaerts, N.; Hoeven, N.; Arenas Esteban, D.; Campos, R.; Mertens, M.; Borah, R.; Glisenti, A.; De Wael, K.; Bals, S.; Lenaerts, S.; Verbruggen, S.W.; Cool, P. url  doi
openurl 
  Title Tuning the turnover frequency and selectivity of photocatalytic CO2 reduction to CO and methane using platinum and palladium nanoparticles on Ti-Beta zeolites Type A1 Journal article
  Year 2021 Publication Chemical Engineering Journal Abbreviated Journal Chem Eng J  
  Volume 410 Issue Pages 128234  
  Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL); Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract A Ti-Beta zeolite was used in gas phase photocatalytic CO2 reduction to reduce the charge recombination rate and increase the surface area compared to P25 as commercial benchmark, reaching 607 m2 g-1. By adding Pt nanoparticles, the selectivity can be tuned toward CO, reaching a value of 92% and a turnover frequency (TOF) of 96 µmol.gcat-1.h-1, nearly an order of magnitude higher in comparison with P25. By adding Pd nanoparticles the selectivity can be shifted from CO (70% for a bare Ti-Beta zeolite), toward CH4 as the prevalent species (60%). In this way, the selectivity toward CO or CH4 can be tuned by either using Pt or Pd. The TOF values obtained in this work outperform reported state-of-the-art values in similar research. The improved activity by adding the nanoparticles was attributed to an improved charge separation efficiency, together with a plasmonic contribution of the metal nanoparticles under the applied experimental conditions.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000623394200004 Publication Date 2021-01-09  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1385-8947 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.216 Times cited 15 Open Access OpenAccess  
  Notes N.B., S.L., S.W.V. and P.C. wish to thank the Flemish government and Catalisti for financial support and coordination in terms of a sprint SBO in the context of the moonshot project D2M. N.H. thanks the Flanders Innovation and Entrepreneurship (VLAIO) for the financial support. The Systemic Physiological and Ecotoxicological Research (SPHERE) group, R. Blust, University of Antwerp is acknowledged for the ICP-MS measurements. Approved (down) Most recent IF: 6.216  
  Call Number EMAT @ emat @c:irua:174591 Serial 6662  
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Author Eliaerts, J.; Meert, N.; Dardenne, P.; Van Durme, F.; Baeten, V.; Samyn, N.; De Wael, K. pdf  url
doi  openurl
  Title Evaluation of a calibration transfer between a bench top and portable Mid-InfraRed spectrometer for cocaine classification and quantification Type A1 Journal article
  Year 2020 Publication Talanta Abbreviated Journal Talanta  
  Volume 209 Issue Pages 120481  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract A portable Fourier Transform Mid-InfraRed (FT-MIR) spectrometer using Attenuated Total Reflectance (ATR) sampling is used for daily routine screening of seized powders. Earlier, ATR-FT-MIR combined with Support Vector Machines (SVM) algorithms resulted in a significant improvement of the screening method to a reliable and straightforward classification and quantification tool for both cocaine and levamisole. However, can this tool be transferred to new (hand-held) devices, without loss of the extensive data set? The objective of this study was to perform a calibration transfer between a newly purchased bench top (BT) spectrometer and a portable (P) spectrometer with existing calibration models. Both instruments are from the same brand and have identical characteristics and acquisition parameters (FT instrument, resolution of 4 cm(-1) and wavenumber range 4000 to 500 cm(-1)). The original SVM classification model (n = 515) and SVM quantification model (n = 378) were considered for the transfer trial. Three calibration transfer strategies were assessed: 1) adjustment of slope and bias; 2) correction of spectra from the new instrument BT to P using Piecewise Direct Standardization (PDS) and 3) building a new mixed instrument model with spectra of both instruments. For each approach, additional cocaine powders were measured (n = 682) and the results were compared with GC-MS and GC-FID. The development of a mixed instrument model was the most successful in terms of performance. The future strategy of a mixed model allows applying the models, developed in the laboratory, to portable instruments that are used on-site, and vice versa. The approach offers opportunities to exchange data within a network of forensic laboratories using other FT-MIR spectrometers.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000509632900016 Publication Date 2019-10-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0039-9140; 1873-3573 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.1 Times cited 2 Open Access  
  Notes ; ; Approved (down) Most recent IF: 6.1; 2020 IF: 4.162  
  Call Number UA @ admin @ c:irua:166475 Serial 6511  
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Author Sciutto, G.; Legrand, S.; Catelli, E.; Prati, S.; Malegori, C.; Oliveri, P.; Janssens, K.; Mazzeo, R. pdf  url
doi  openurl
  Title Macroscopic mid-FTIR mapping and clustering-based automated data-reduction : an advanced diagnostic tool for in situ investigations of artworks Type A1 Journal article
  Year 2020 Publication Talanta Abbreviated Journal Talanta  
  Volume 209 Issue Pages 120575-120577  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract The present study describes a multivariate strategy that can be used for automatic on-site processing of reflection mode macro FTIR mapping (MA-rFTIR) data obtained during investigation of artworks. The chemometric strategy is based on the integration of principal component analysis (PCA) with a clustering approach in the space subtended by the three lowest-order principal components and allows to automatically identify the regions of interest (ROIs) of the area scanned and to extract the average FTIR spectra related to each ROI. Thanks to the automatic data management, in-field HSI (hyperspectral imaging)-based analyses may be performed even by staff lacking specific advanced chemometric expertise, as it is sometimes the case for conservation scientists or conservators with a scientific background. MA-rFTIR was only recently introduced in the conservation field and, in this work the technique was employed to characterize the surface of metallic artefacts. The analytical protocol was employed as part of a rapid procedure to evaluate the conservation state and the performance of cleaning methods on bronze objects. Both activities are commonly part of restoration campaigns of bronzes and require an on-site analytical procedure for efficient and effective diagnosis. The performance of the method was first evaluated on aged standard samples (bronzes with a layer of green basic copper hydroxysulphate, treated with different organic coatings) and then scrutinized in situ on areas of the 16th century Neptune fountain statue (Piazza del Nettuno, Bologna, Italy) by Gianbologna.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000509632900088 Publication Date 2019-11-19  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0039-9140; 1873-3573 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.1 Times cited Open Access  
  Notes ; ; Approved (down) Most recent IF: 6.1; 2020 IF: 4.162  
  Call Number UA @ admin @ c:irua:166476 Serial 6557  
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Author Horemans, B.; Van Holsbeke, C.; Vos, W.; Darchuk, L.; Novakovic, V.; Fontan, A.C.; de Backer, J.; van Grieken, R.; de Backer, W.; De Wael, K. doi  openurl
  Title Particle deposition in airways of chronic respiratory patients exposed to an urban aerosol Type A1 Journal article
  Year 2012 Publication Environmental science and technology Abbreviated Journal Environ Sci Technol  
  Volume 46 Issue 21 Pages 12162-12169  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Laboratory Experimental Medicine and Pediatrics (LEMP)  
  Abstract Urban atmospheres in modern cities carry characteristic mixtures of particulate pollution which are potentially aggravating for chronic respiratory patients (CRP). Although air quality surveys can be detailed, the obtained information is not always useful to evaluate human health effects. This paper presents a novel approach to estimate particle deposition rates in airways of CRP, based on real air pollution data. By combining computational fluid dynamics with physical-chemical characteristics of particulate pollution, deposition rates are estimated for particles of different toxicological relevance, that is, minerals, iron oxides, sea salts, ammonium salts, and carbonaceous particles. Also, it enables some qualitative evaluation of the spatial, temporal, and patient specific effects on the particle dose upon exposure to the urban atmosphere. Results show how heavy traffic conditions increases the deposition of anthropogenic particles in the trachea and lungs of respiratory patients (here, +0.28 and +1.5 μg·h1, respectively). In addition, local and synoptic meteorological conditions were found to have a strong effect on the overall dose. However, the pathology and age of the patient was found to be more crucial, with highest deposition rates for toxic particles in adults with a mild anomaly, followed by mild asthmatic children and adults with severe respiratory dysfunctions (7, 5, and 3 μg·h1, respectively).  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Easton, Pa Editor  
  Language Wos 000310665000082 Publication Date 2012-10-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0013-936X;1520-5851; ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.198 Times cited 5 Open Access  
  Notes ; We are grateful for the financial support of n.v. Vooruitzicht. Furthermore, co-workers at the environmental analysis research group are acknowledged for their help in the fieldwork. ; Approved (down) Most recent IF: 6.198; 2012 IF: 5.257  
  Call Number UA @ lucian @ c:irua:101411 Serial 2557  
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Author Denecke, M.A.; Janssens, K.; Proost, K.; Rothe, J.; Noseck, U. doi  openurl
  Title Confocal micrometer-scale X-ray fluorescence and X-ray absorption fine structure studies of uranium speciation in a tertiary sediment from a waste disposal natural analogue site Type A1 Journal article
  Year 2005 Publication Environmental science and technology Abbreviated Journal Environ Sci Technol  
  Volume 39 Issue Pages 2049-2058  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000228172600031 Publication Date 2005-03-30  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0013-936x; 1520-5851 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.198 Times cited 47 Open Access  
  Notes Approved (down) Most recent IF: 6.198; 2005 IF: 4.054  
  Call Number UA @ admin @ c:irua:52232 Serial 5554  
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Author Terzano, R.; Spagnuolo, M.; Medici, L.; Vekemans, B.; Vincze, L.; Janssens, K.; Ruggiero, P. doi  openurl
  Title Copper stabilization by zeolite synthesis in polluted soils treated with coal fly ash Type A1 Journal article
  Year 2005 Publication Environmental science and technology Abbreviated Journal Environ Sci Technol  
  Volume 39 Issue 16 Pages 6280-6287  
  Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)  
  Abstract This study deals with the process of zeolite formation in an agricultural soil artificially polluted by high amounts of Cu (15 mg of Cu/g of soil dry weight) and treated with fused coal fly ash at 30 and 60 degrees C and how this process affects the mobility and availability of the metal. As a consequence of the treatment, the amount of dissolved Cu, and thus its mobility, was strongly reduced, and the percentage of the metal stabilized in the solid phase increased over time, reaching values of 30% at 30 degrees C and 40% at 60 degrees C. The physicochemical phenomena responsible for Cu stabilization in the solid phase have been evaluated by EDTA sequential extractions and synchrotron radiation based X-ray microanalytical techniques. These techniques were used for the visualization of the spatial distribution and the speciation of Cu in and/or on the neo-formed zeolite particles. In particular, micro XRF (X-ray fluorescence) tomography showed direct evidence that Cu can be entrapped as clusters inside the porous zeolitic structures while,mu-XANES (X-ray absorption near edge structure) spectroscopy determinations revealed Cu to be present mainly as Cu(II) hydroxide and Cu(II) oxide. The reported results could be useful as a basic knowledge for planning new technologies for the on site physicochemical stabilization of heavy metals in heavily polluted soils.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000231203100053 Publication Date 2005-08-11  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0013-936x; 1520-5851 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.198 Times cited 39 Open Access  
  Notes Approved (down) Most recent IF: 6.198; 2005 IF: 4.054  
  Call Number UA @ admin @ c:irua:103658 Serial 5560  
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