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Author Alvarez-Martin, A.; Quanico, J.; Scovacricchi, T.; Avranovich Clerici, E.; Baggerman, G.; Janssens, K.
Title Chemical mapping of the degradation of geranium lake in paint cross sections by MALDI-MSI Type A1 Journal article
Year 2023 Publication Analytical chemistry Abbreviated Journal
Volume 95 Issue 49 Pages 18215-18223
Keywords A1 Journal article; Antwerp X-ray Imaging and Spectroscopy (AXIS); Ecosphere
Abstract Matrix assisted laser desorption ionization-mass spectrometry imaging (MALDI-MSI) has become a powerful method to extract spatially resolved chemical information in complex materials. This study provides the first use of MALDI-MSI to define spatial–temporal changes in oil paints. Due to the highly heterogeneous nature of oil paints, the sample preparation had to be optimized to prevent molecules from delocalizing. Here, we present a new protocol for the layer-specific analysis of oil paint cross sections achieving a lateral resolution of 10 μm and without losing ionization efficiency due to topographic effects. The efficacy of this method was investigated in oil paint samples containing a mixture of two historic organic pigments, geranium lake and lead white, a mixture often employed in the work of painter Vincent Van Gogh. This methodology not only allows for spatial visualization of the molecules responsible for the pink hue of the paint but also helps to elucidate the chemical changes behind the discoloration of paintings with this composition. The results demonstrate that this approach provides valuable molecular compositional information about the degradation pathways of pigments in specific paint layers and their interaction with the binding medium and other paint components and with light over time. Since a spatial correlation between molecular species and the visual pattern of the discoloration pattern can be made, we expect that mass spectrometry imaging will become highly relevant in future degradation studies of many more historical pigments and paints.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001142876000001 Publication Date 2023-11-23
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 7.4 Times cited Open Access
Notes Approved Most recent IF: 7.4; 2023 IF: 6.32
Call Number (up) UA @ admin @ c:irua:201644 Serial 9007
Permanent link to this record
 

 
Author Steijlen, A.S.M.; Parrilla, M.; Van Echelpoel, R.; De Wael, K.
Title Dual microfluidic sensor system for enriched electrochemical profiling and identification of illicit drugs on-site Type A1 Journal article
Year 2024 Publication Analytical chemistry Abbreviated Journal
Volume 96 Issue 1 Pages 590-598
Keywords A1 Journal article; Engineering sciences. Technology; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab)
Abstract Electrochemical sensors have emerged as a new analytical tool for illicit drug detection to facilitate ultrafast and accurate identification of suspicious compounds on-site. Drugs of abuse can be identified using their unique voltammetric fingerprint at a given pH. Today, the right buffer solution is manually selected based on drug appearance, and in some cases, a consecutive analysis in two different pH solutions is required. In this work, we present a disposable microfluidic multichannel sensor system that automatically records fingerprints in two pH solutions (e.g., pH 5 and pH 12). This system has two advantages. It will overcome the manual selection of a buffer solution at the right pH, decrease analysis time, and minimize the risk of human errors. Second, the combination of two fingerprints, the superfingerprint, contains more detailed information about the samples, which enhances the selectivity of the analytical technique. First, real-time pH measurements proved that the sample can be brought to the desired pH within a minute. Subsequently, an electrochemical study on the microfluidic platform with 1 mM illicit drug standards of MDMA, cocaine, heroin, and methamphetamine showed that the characteristic voltammetric fingerprints and peak potentials are reproducible, also in the presence of common cutting agents. Finally, the microfluidic concept was validated with real confiscated samples, showing promising results for the user-friendly identification of drugs of abuse. In short, this paper presents a successful proof-of-concept study of a multichannel microfluidic sensor system to enrich the fingerprints of illicit drugs at pH 5 and pH 12, thus providing a low-cost, portable, and rapid identification system of illicit drugs with minimal user intervention.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 001139443500001 Publication Date 2023-12-28
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 7.4 Times cited Open Access Not_Open_Access
Notes Approved Most recent IF: 7.4; 2024 IF: 6.32
Call Number (up) UA @ admin @ c:irua:201877 Serial 9024
Permanent link to this record
 

 
Author Török, S.; Labar, J.; Schmeling, M.; Van Grieken, R.
Title X-ray spectrometry Type A1 Journal article
Year 1998 Publication Analytical chemistry Abbreviated Journal
Volume 70 Issue Pages 495r-517r
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000074161100020 Publication Date
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:20967 Serial 8776
Permanent link to this record
 

 
Author Ro, C.-U.; Osán, J.; Van Grieken, R.
Title Determination of low-Z elements in individual environmental particles using windowless EPMA Type A1 Journal article
Year 1999 Publication Analytical chemistry Abbreviated Journal
Volume 71 Issue 8 Pages 1521-1528
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000079756900007 Publication Date 2002-07-26
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:23185 Serial 7782
Permanent link to this record
 

 
Author Tsuji, K.; Wagatsuma, K.; Nullens, R.; Van Grieken, R.E.
Title Grazing exit electron probe microanalysis for surface and particle analysis Type A1 Journal article
Year 1999 Publication Analytical chemistry Abbreviated Journal
Volume 71 Issue 13 Pages 2497-2501
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000081265600046 Publication Date 2002-07-26
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:24723 Serial 8008
Permanent link to this record
 

 
Author Tsuji, K.; Spolnik, Z.; Wagatsuma, K.; Van Grieken, R.E.; Vis, R.D.
Title Grazing-exit particle-induced X-ray emission analysis with extremely low background Type A1 Journal article
Year 1999 Publication Analytical chemistry Abbreviated Journal
Volume 71 Issue 22 Pages 5033-5036
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000083647100004 Publication Date 2002-07-26
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:27588 Serial 8010
Permanent link to this record
 

 
Author Szalóki, I.; Török, S.B.; Ro, C.-U.; Injuk, J.; Van Grieken, R.E.
Title X-ray spectrometry Type A1 Journal article
Year 2000 Publication Analytical chemistry Abbreviated Journal
Volume 72 Issue 12 Pages 211-233
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000087661500018 Publication Date 2002-07-26
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:27850 Serial 8774
Permanent link to this record
 

 
Author Blockhuys, F.; Claes, M.; Van Grieken, R.; Geise, H.J.
Title Assessing the molecular weight of a conducting polymer by grazing emission XRF Type A1 Journal article
Year 2000 Publication Analytical chemistry Abbreviated Journal
Volume 72 Issue 14 Pages 3366-3368
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000088347100054 Publication Date 2002-07-26
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:27915 Serial 7497
Permanent link to this record
 

 
Author Török, S.B.; Van Grieken, R.E.
Title X-ray spectrometry Type A1 Journal article
Year 1992 Publication Analytical chemistry Abbreviated Journal
Volume 64r Issue Pages 180-196
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos A1992HZ51800011 Publication Date
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:2823 Serial 8778
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Author Ro, C.-U.; Oh, K.-Y.; Osán, J.; de Hoog, J.; Worobiec, A.; Van Grieken, R.
Title Heterogeneity assessment in individual CaCO3-CaSO4 particles using ultrathin window electron probe X-ray microanalysis Type A1 Journal article
Year 2001 Publication Analytical chemistry Abbreviated Journal
Volume 73 Issue 19 Pages 4574-4583
Keywords A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000171356800012 Publication Date 2002-07-26
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:36085 Serial 8028
Permanent link to this record
 

 
Author Vincze, L.; Somogyi, A.; Osán, J.; Vekemans, B.; Török, S.; Janssens, K.; Adams, F.
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 Most recent IF: 6.32; 2002 IF: 5.094
Call Number (up) UA @ admin @ c:irua:38377 Serial 5796
Permanent link to this record
 

 
Author Szalóki, I.; Török, S.B.; Injuk, J.; Van Grieken, R.E.
Title X-ray spectrometry Type A1 Journal article
Year 2002 Publication Analytical chemistry Abbreviated Journal
Volume 74 Issue 12 Pages 2895-2918
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000176253700020 Publication Date 2002-07-26
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:39517 Serial 8773
Permanent link to this record
 

 
Author Kempenaers, L.; Janssens, K.; Vincze, L.; Vekemans, B.; Somogyi, A.; Drakopoulos, M.; Simionovici, A.S.; Adams, F.
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 Most recent IF: 6.32; 2002 IF: 5.094
Call Number (up) UA @ admin @ c:irua:39871 Serial 5734
Permanent link to this record
 

 
Author Ro, C.-U.; Osán, J.; Szalóki, I.; de Hoog, J.; Worobiec, A.; Van Grieken, R.
Title A Monte Carlo program for quantitative electron-induced x-ray analysis of individual particles Type A1 Journal article
Year 2003 Publication Analytical chemistry Abbreviated Journal
Volume 75 Issue 4 Pages 851-859
Keywords A1 Journal article; Laboratory Experimental Medicine and Pediatrics (LEMP); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000181073800021 Publication Date 2003-02-14
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:40613 Serial 8279
Permanent link to this record
 

 
Author Ro, C.-U.; Kim, H.K.; Van Grieken, R.
Title An expert system for chemical speciation of individual particles using low-Z particle electron probe X-ray microanalysis data Type A1 Journal article
Year 2004 Publication Analytical chemistry Abbreviated Journal
Volume 76 Issue Pages 1322-1327
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000189275100020 Publication Date 2004-02-27
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:43879 Serial 7949
Permanent link to this record
 

 
Author Szalóki, I.; Osán, J.; Van Grieken, R.E.
Title X-ray spectrometry Type A1 Journal article
Year 2004 Publication Analytical chemistry Abbreviated Journal
Volume 76 Issue 12 Pages 3445-3470
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000222011100014 Publication Date 2004-06-14
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:46259 Serial 8772
Permanent link to this record
 

 
Author Vincze, L.; Vekemans, B.; Brenker, F.E.; Falkenberg, G.; Rickers, K.; Somogyi, A.; Kersten, M.; Adams, F.
Title Three-dimensional trace element analysis by confocal X-ray microfluorescence imaging Type A1 Journal article
Year 2004 Publication Analytical chemistry Abbreviated Journal
Volume 76 Issue 22 Pages 6786-6791
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000225076400034 Publication Date 2004-11-12
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:49817 Serial 8669
Permanent link to this record
 

 
Author Choël, M.; Deboudt, K.; Osán, J.; Flament, P.; Van Grieken, R.
Title Quantitative determination of low-Z elements in single atmospheric particles on boron substrates by automated scanning electron microscopy: energy-dispersive X-ray spectrometry Type A1 Journal article
Year 2005 Publication Analytical chemistry Abbreviated Journal
Volume 77 Issue 17 Pages 5686-5692
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000231652300046 Publication Date 2005-08-31
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:53593 Serial 8443
Permanent link to this record
 

 
Author Szalóki, I.; Osán, J.; Van Grieken, R.E.
Title X-ray spectrometry Type A1 Journal article
Year 2006 Publication Analytical chemistry Abbreviated Journal
Volume 78 Issue 12 Pages 4069-4096
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000238252600016 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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:58857 Serial 8771
Permanent link to this record
 

 
Author Bulska, E.; Wysocka, I.A.; Wierzbicka, M.H.; Proost, K.; Janssens, K.; Falkenberg, G.
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
Address
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 Most recent IF: 6.32; 2006 IF: 5.646
Call Number (up) UA @ admin @ c:irua:60714 Serial 5659
Permanent link to this record
 

 
Author van Meel, K.; Smekens, A.; Behets, M.; Kazandjian, P.; Van Grieken, R.
Title Determination of platinum, palladium, and rhodium in automotive catalysts using high-energy secondary target X-ray fluorescence spectrometry Type A1 Journal article
Year 2007 Publication Analytical chemistry Abbreviated Journal
Volume 79 Issue 16 Pages 6383-6389
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000248993300042 Publication Date 2007-07-13
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:64781 Serial 7784
Permanent link to this record
 

 
Author Camerani, M.C.; Somogyi, A.; Vekemans, B.; Ansell, S.; Simionovici, A.S.; Steenari, B.-M.; Panas, I.
Title Determination of the cd-bearing phases in municipal solid waste and Biomass single fly ash particles using SR-mu XRF Spectroscopy Type A1 Journal article
Year 2007 Publication Analytical chemistry Abbreviated Journal
Volume 79 Issue 17 Pages 6496-6506
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000249242900017 Publication Date 2007-08-04
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:66600 Serial 7790
Permanent link to this record
 

 
Author Marguí, E.; Fontàs, C.; van Meel, K.; Van Grieken, R.; Queralt, I.; Hidalgo, M.
Title High-energy polarized-beam energy-dispersive X-ray fluorescence analysis combined with activated thin layers for cadmium determination at trace levels in complex environmental liquid samples Type A1 Journal article
Year 2008 Publication Analytical chemistry Abbreviated Journal
Volume 80 Issue 7 Pages 2357-2364
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000254593500015 Publication Date 2008-03-08
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:68425 Serial 8032
Permanent link to this record
 

 
Author Marguí, E.; van Meel, K.; Van Grieken, R.; Buendía, A.; Fontás, C.; Hidalgo, M.; Queralt, I.
Title Method for the determination of Pd-catalyst residues in active pharmaceutical ingredients by means of high-energy polarized-beam energy dispersive X-ray fluorescence Type A1 Journal article
Year 2009 Publication Analytical chemistry Abbreviated Journal
Volume 81 Issue 4 Pages 1404-1410
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract In medicinal chemistry, Pd is perhaps the most-widely utilized precious metal, as catalyst in reactions which represent key transformations toward the synthesis of new active pharmaceutical ingredients (APIs). The disadvantage of this metal-catalyzed chemistry is that expensive and toxic metal residues are invariably left bound to the desired product. Thus, stringent regulatory guidelines exist for the amount of residual Pd that a drug candidate is allowed to contain. In this work, a rapid and simple method for the determination of Pd in API samples by high-energy polarized-beam energy dispersive X-ray fluorescence spectrometry has been developed and validated according to the specification limits of current legislation (10 mg kg−1 Pd) and the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH guidelines). Sample and calibration standards preparation includes a first step of homogenization and then, in a second step, the pressing of the powdered material into pellets without any chemical treatment. The use of several synthetic calibration standards made of cellulose to simulate the API matrix appears to be an effective means to obtain reliable calibration curves with a good spread of data points over the working range. With the use of the best measuring conditions, the limit of detection (0.11 mg kg−1 Pd) as well as the limit of quantitation (0.37 mg kg−1 Pd) achieved meet rigorous requirements. The repeatability of the XRF measurement appeared to be less than 2%, while the precision of the whole method was around 7%. Trueness was evaluated by analyzing spiked API samples at the level of the specification limit and calculating the recovery factor, which was better than 95%. To study the applicability of the developed methodology for the intended purpose, three batches of the studied API were analyzed for their Pd content, and the attained results were comparable to those obtained by the daily routine method (acid digestion plus atomic spectroscopy) used in most pharmaceutical laboratories.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000263319000015 Publication Date 2009-01-22
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:74340 Serial 8220
Permanent link to this record
 

 
Author Dik, J.; Janssens, K.; van der Snickt, G.; van der Loeff, L.; Rickers, K.; Cotte, M.
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 Most recent IF: 6.32; 2008 IF: 5.712
Call Number (up) UA @ admin @ c:irua:74466 Serial 5906
Permanent link to this record
 

 
Author van der Snickt, G.; Dik, J.; Cotte, M.; Janssens, K.; Jaroszewicz, J.; de Nolf, W.; Groenewegen, J.; van der Loeff, L.
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.
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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 Most recent IF: 6.32; 2009 IF: 5.214
Call Number (up) UA @ admin @ c:irua:76415 Serial 5501
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Author Monico, L.; van der Snickt, G.; Janssens, K.; de Nolf, W.; Miliani, C.; Dik, J.; Radepont, M.; Hendriks, E.; Geldof, M.; Cotte, M.
Title Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods : 2 : original paint layer samples Type A1 Journal article
Year 2011 Publication Analytical chemistry Abbreviated Journal Anal Chem
Volume 83 Issue 4 Pages 1224-1231
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract The darkening of the original yellow areas painted with the chrome yellow pigment (PbCrO4, PbCrO4·xPbSO4, or PbCrO4·xPbO) is a phenomenon widely observed on several paintings by Vincent van Gogh, such as the famous different versions of Sunflowers. During our previous investigations on artificially aged model samples of lead chromate, we established for the first time that darkening of chrome yellow is caused by reduction of PbCrO4 to Cr2O3·2H2O (viridian green), likely accompanied by the presence of another Cr(III) compound, such as either Cr2(SO4)3·H2O or (CH3CO2)7Cr3(OH)2 [chromium(III) acetate hydroxide]. In the second part of this work, in order to demonstrate that this reduction phenomenon effectively takes place in real paintings, we study original paint samples from two paintings of V. van Gogh. As with the model samples, in view of the thin superficial alteration layers that are present, high lateral resolution spectroscopic methods that make use of synchrotron radiation (SR), such as microscopic X-ray absorption near edge (μ-XANES) and X-ray fluorescence spectrometry (μ-XRF) were employed. Additionally, μ-Raman and mid-FTIR analyses were carried out to completely characterize the samples. On both paint microsamples, the local presence of reduced Cr was demonstrated by means of μ-XANES point measurements. The presence of Cr(III) was revealed in specific areas, in some cases correlated to the presence of Ba(sulfate) and/or to that of aluminum silicate compounds.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000287176900012 Publication Date 2011-02-14
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 84 Open Access
Notes ; This research was funded by grants from ESRF (experiment EC-504) and by HASYLAB (experiments 11-20080130 EC and 11-20070157 EC) and was supported by the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) project nos. G.0103.04, G.0689.06, and G.0704.08. The staff of the Van Gogh Museum, Amsterdam, is acknowledged for their agreeable cooperation and for the authorization to publish the images of the paintings in this article. L.M. was financially supported by the Erasmus Placement in the framework of Lifelong Learning Programme (A.Y. 2009-2010). The EU Community's FP7 Research Infrastructures program under the CHARISMA Project (Grant Agreement 228330) is also acknowledged. ; Approved Most recent IF: 6.32; 2011 IF: 5.856
Call Number (up) UA @ admin @ c:irua:88795 Serial 5571
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Author Rouchon, V.; Duranton, M.; Burgaud, C.; Pellizzi, E.; Lavédrine, B.; Janssens, K.; de Nolf, W.; Nuyts, G.; Vanmeert, F.; Hellemans, K.
Title Room-temperature study of iron gall ink impregnated paper degradation under various oxygen and humidity conditions : time-dependent monitoring by viscosity and X-ray absorption near-edge spectrometry measurements Type A1 Journal article
Year 2011 Publication Analytical chemistry Abbreviated Journal Anal Chem
Volume 83 Issue 7 Pages 2589-2597
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Many western manuscripts were written using iron gall inks. These inks can damage the paper via two major mechanisms: (a) acid hydrolysis, enhanced by humidity, and (b) oxidative depolymerization provoked by the presence of oxygen and free iron(II) ions. The degradation of unsized Whatman paper impregnated with different combinations of iron sulfate, gallic acid, and gum arabic was studied at room temperature in order to assess the relative importance of each mechanism. The samples were stored in various environments including a dry and/or an oxygen-free atmosphere. The cellulose depolymerization was monitored by viscometry and related to changes in the oxidation state of iron, determined by X-ray absorption near-edge spectrometry. The results indicate that residual amounts of oxygen (less than 0.1%) promote cellulose depolymerization, whereas the level of relative humidity has no impact. The cellulose depolymerization also appears closely correlated to oxidative mechanisms. Regarding the oxidation of iron, it only occurs in the simultaneous presence of oxygen and moisture, suggesting the occurrence of rustlike oxidative mechanisms. Finally, the presence of gallic acid has a strong influence, which is only partially explained by its capacity to reduce iron(III) to iron(II).
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000288887700028 Publication Date 2011-03-04
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 28 Open Access
Notes ; This research was supported by the French Ministry of Culture within the National Program of Research (“La conservation des manuscrits: etude du vieillissement naturel de papiers impregnes d'encres ferrogalliques”). It was funded by grants from HASYLAB (experiments I-20090280 EC and II-20060245 EC) and SOLEIL (proposals 20060396 and 20080761) and was supported by the Interuniversity Attraction Poles Programme Belgian Science Policy (1UAP V1/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects nos. G.0689.06, G.0704.08 and G017909N. We are thankful to Dr. Dominique Thaudiere, Dr. Solenn Reguer, Dr. Andrea Somogyi, Dr. Karen Appel, Dr. Manuela Borchert, and Dr. Gerald Falkenberg for their assistance and help during the experiments performed at SOLEIL beamline “DIFFABS” and at HASYLAB Beam line “L” respectively. ; Approved Most recent IF: 6.32; 2011 IF: 5.856
Call Number (up) UA @ admin @ c:irua:89593 Serial 5822
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Author Romero-Pastor, J.; Duran, A.; Rodríguez-Navarro, A.B.; Van Grieken, R.; Cardell, C.
Title Compositional and quantitative microtextural characterization of historic paintings by micro-X-ray diffraction and Raman microscopy Type A1 Journal article
Year 2011 Publication Analytical chemistry Abbreviated Journal
Volume 83 Issue 22 Pages 8420-8428
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract This work shows the benefits of characterizing historic paintings via compositional and microtextural data from micro-X-ray diffraction (μ-XRD) combined with molecular information acquired with Raman microscopy (RM) along depth profiles in paint stratigraphies. The novel approach was applied to identify inorganic and organic components from paintings placed at the 14th century Islamic UniversityMadrasah Yusufiyyain Granada (Spain), the only Islamic University still standing from the time of Al-Andalus (Islamic Spain). The use of μ-XRD to obtain quantitative microtextural information of crystalline phases provided by two-dimensional diffraction patterns to recognize pigments nature and manufacture, and decay processes in complex paint cross sections, has not been reported yet. A simple Nasrid (14th century) palette made of gypsum, vermilion, and azurite mixed with glue was identified in polychromed stuccos. Here also a Christian intervention was found via the use of smalt, barite, hematite, Brunswick green and gold; oil was the binding media employed. On mural paintings and wood ceilings, more complex palettes dated to the 19th century were found, made of gypsum, anhydrite, barite, dolomite, calcite, lead white, hematite, minium, synthetic ultramarine blue, and black carbon. The identified binders were glue, egg yolk, and oil.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000296830200011 Publication Date 2011-10-10
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 Times cited Open Access
Notes Approved no
Call Number (up) UA @ admin @ c:irua:92679 Serial 7715
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Author De Wael, K.; Daems, D.; Van Camp, G.; Nagels, L.J.
Title The use of potentiometric sensors to study (bio)molecular interactions Type A1 Journal article
Year 2012 Publication Analytical chemistry Abbreviated Journal Anal Chem
Volume 84 Issue 11 Pages 4921-4927
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation)
Abstract Potentiometric sensors were used to study molecular interactions in liquid environments, with sensorgram methodology. This is demonstrated with a lipophilic rubber-, and with a collagen based hydrogel sensor coating. The investigated molecules were promazine and tartaric acid respectively. The sensors were placed in a hydrodynamic wall jet system for the recording of sensorgrams. mV sensor responses were first converted to a signal, expressing the concentration of adsorbed organic ions. Using a linearization method, a pseudo first order kinetic model of adsorption was shown to fit the experimental results perfectly. Kass, kon and koff values were calculated.. The technique can be used over 4 decades of concentration, and it is very sensitive to low MW compounds as well as to multiply charged large biomolecules. This study is the first to demonstrate the application of potentiometric sensors as an alternative and complement to SPR methods.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000304783100041 Publication Date 2012-04-28
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 10 Open Access
Notes ; Financial support for this work was provided by the University of Antwerp by granting D.D. a BOF interdisciplinary research project. We thank J. Everaert for his help in interpreting the results. K.D.W. and D.D. contributed equally to this work. ; Approved Most recent IF: 6.32; 2012 IF: 5.695
Call Number (up) UA @ admin @ c:irua:97520 Serial 5898
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