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Denoyer, E.; Van Grieken, R.; Adams, F.; Ntausch, D.F.S. | ||||
| Title | Laser microprobe mass spectrometry : 1 : basic principles and performance characteristics | Type | A1 Journal article | ||
| Year | 1982 | Publication | Analytical chemistry | Abbreviated Journal | |
| Volume | 54 | Issue | 1 | Pages | 26a-33a |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | Publication Date | 2012-05-29 | ||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record | |
| Impact Factor | Times cited | Open Access | |||
| Notes | Approved | no | |||
| Call Number | UA @ admin @ c:irua:116517 | Serial | 8164 | ||
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| 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. | ||||
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| 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 | UA @ admin @ c:irua:74466 | Serial | 5906 | ||
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| Author |
Florea, A.; Schram, J.; De Jong, M.; Eliaerts, J.; Van Durme, F.; Kaur, B.; Samyn, N.; De Wael, K. | ||||
| 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. | ||||
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| 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 | Most recent IF: 6.32 | ||
| Call Number | UA @ admin @ c:irua:160061 | Serial | 5596 | ||
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| Author |
Fuchs, J.; Aghaei, M.; Schachel, T.D.; Sperling, M.; Bogaerts, A.; Karst, U. | ||||
| Title | Impact of the Particle Diameter on Ion Cloud Formation from Gold Nanoparticles in ICPMS | Type | A1 Journal article | ||
| Year | 2018 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
| Volume | 90 | Issue | 17 | Pages | 10271-10278 |
| Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract | The unique capabilities of microsecond dwell time (DT) single-particle inductively coupled plasma mass spectrometry (spICPMS) were utilized to characterize the cloud of ions generated from the introduction of suspensions of gold nanoparticles (AuNPs) into the plasma. A set of narrowly distributed particles with diameters ranging from 15.4 to 100.1 nm was synthesized and characterized according to established protocols. Statistically significant numbers of the short transient spICPMS events were evaluated by using 50 μs DT for their summed intensity, maximum intensity, and duration, of which all three were found to depend on the particle diameter. The summed intensity increases from 10 to 1661 counts and the maximum intensity from 6 to 309 counts for AuNPs with diameters from 15.4 to 83.2 nm. The event duration rises from 322 to 1007 μs upon increasing AuNP diameter. These numbers represent a comprehensive set of key data points of the ion clouds generated in ICPMS from AuNPs. The extension of event duration is of high interest to appoint the maximum possible particle number concentration at which separation of consecutive events in spICPMS can still be achieved. Moreover, the combined evaluation of all above-mentioned ion cloud characteristics can explain the regularly observed prolonged single-particle events. The transport and ionization behavior of AuNPs in the ICP was also computationally modeled to gain insight into the size-dependent signal generation. The simulated data reveals that the plasma temperature, and therefore the point of ionization of the particles, is the same for all diameters. However, the maximum number density of Au+, as well as the extent of the ion cloud, depends on the particle diameter, in agreement with the experimental data, and it provides an adequate explanation for the observed ion cloud characteristics. | ||||
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| Language | Wos | 000444060600028 | Publication Date | 2018-09-04 | |
| 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 | 5 | Open Access | OpenAccess |
| Notes | We thank Dr. Harald Rösner from the Institute of Materials Physics of the University of Münster for the TEM imaging. | Approved | Most recent IF: 6.32 | ||
| Call Number | PLASMANT @ plasmant @c:irua:153651 | Serial | 5057 | ||
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| Author |
Girard-Sahun, F.; Lefrancois, P.; Badets, V.; Arbault, S.; Clement, F. | ||||
| Title | Direct sensing of superoxide and its relatives reactive oxygen and nitrogen species in phosphate buffers during cold atmospheric plasmas exposures | Type | A1 Journal article | ||
| Year | 2022 | Publication | Analytical Chemistry | Abbreviated Journal | Anal Chem |
| Volume | 94 | Issue | 14 | Pages | 5555-5565 |
| Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract | This study aims at sensing in situ reactive oxygen and nitrogen species (RONS) and specifically superoxide anion (O-2(center dot-)) in aqueous buffer solutions exposed to cold atmospheric plasmas (CAPs). CAPs were generated by ionizing He gas shielded with variable N-2/O-2 mixtures. Thanks to ultramicroelectrodes protected against the high electric fields transported by the ionization waves of CAPs, the production of superoxide and several RONS was electrochemically directly detected in liquids during their plasma exposure. Complementarily, optical emissive spectroscopy (OES) was used to study the plasma phase composition and its correlation with the chemistry in the exposed liquid. The specific production of O-2(center dot-), a biologically reactive redox species, was analyzed by cyclic voltammetry (CV), in both alkaline (pH 11), where the species is fairly stable, and physiological (pH 7.4) conditions, where it is unstable. To understand its generation with respect to the plasma chemistry, we varied the shielding gas composition of CAPs to directly impact on the RONS composition at the plasma-liquid interface. We observed that the production and accumulation of RONS in liquids, including O(2)(center dot-)depends on the plasma composition, with N-2-based shieldings providing the highest superoxide concentrations (few 10s of micromolar at most) and of its derivatives (hundreds of micromolar). In situ spectroscopic and electrochemical analyses provide a high resolution kinetic and quantitative understanding of the interactions between CAPs and physiological solutions for biomedical applications. | ||||
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| Language | Wos | 000805334400013 | Publication Date | 2022-03-28 | |
| 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 | |
| Impact Factor | 7.4 | Times cited | Open Access | OpenAccess | |
| Notes | Approved | Most recent IF: 7.4 | |||
| Call Number | UA @ admin @ c:irua:189093 | Serial | 7143 | ||
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| Author |
Gorbanev, Y.; Privat-Maldonado, A.; Bogaerts, A. | ||||
| Title | Analysis of Short-Lived Reactive Species in Plasma–Air–Water Systems: The Dos and the Do Nots | Type | A1 Journal Article | ||
| Year | 2018 | Publication | Analytical Chemistry | Abbreviated Journal | Anal Chem |
| Volume | 90 | Issue | 22 | Pages | 13151-13158 |
| Keywords | A1 Journal Article; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; | ||||
| Abstract | This Feature addresses the analysis of the reactive species generated by nonthermal atmospheric pressure plasmas, which are widely employed in industrial and biomedical research, as well as first clinical applications. We summarize the progress in detection of plasma-generated short-lived reactive oxygen and nitrogen species in aqueous solutions, discuss the potential and limitations of various analytical methods in plasma−liquid systems, and provide an outlook on the possible future research goals in development of short-lived reactive species analysis methods for a general nonspecialist audience. |
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| Language | Wos | 000451246100002 | Publication Date | 2018-11-20 | |
| 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 | 17 | Open Access | Not_Open_Access |
| Notes | European Commission, 743151 ; This work was supported by the European Marie Sklodowska- Curie Individual Fellowship within Horizon2020 (“LTPAM”, Grant No. 743151). | Approved | Most recent IF: 6.32 | ||
| Call Number | PLASMANT @ plasmant @c:irua:156301 | Serial | 5152 | ||
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| Author |
Gregory, C.L.; Nullens, H.A.; Gijbels, R.H.; van Espen, P.J.; Geuens, I.; de Keyzer, R. | ||||
| Title | Automated particle analysis of populations of silver halide microcrystals by electron probe microanalysis under cryogenic conditions | Type | A1 Journal article | ||
| Year | 1998 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
| Volume | 70 | Issue | Pages | 2551-2559 | |
| Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Chemometrics (Mitac 3) | ||||
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| Publisher | Place of Publication | Washington, D.C. | Editor | ||
| Language | Wos | 000074584700047 | Publication Date | 2002-07-26 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0003-2700;1520-6882; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 6.32 | Times cited | 12 | Open Access | |
| Notes | Approved | Most recent IF: 6.32; 1998 IF: 4.580 | |||
| Call Number | UA @ lucian @ c:irua:21308 | Serial | 210 | ||
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| Author |
Hamidi-Asl, E.; Daems, D.; De Wael, K.; Van Camp, G.; Nagels, L.J. | ||||
| Title | Concentration related response potentiometric titrations to study the interaction of small molecules with large biomolecules | Type | A1 Journal article | ||
| Year | 2014 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
| Volume | 86 | Issue | 24 | Pages | 12243-12249 |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract | In the present article, the utility of a special potentiometric titration approach for recognition and calculation of biomolecule/small molecule interactions is reported. This approach is fast, sensitive, reproducible and inexpensive in comparison to the other methods for the determination of the association constant values (Ka) and the interaction energies (ΔG). The potentiometric titration measurement is based on the use of a classical polymeric membrane indicator electrode in a solution of the small molecule ligand. The biomolecule is used as a titrant. The potential is measured versus a reference electrode and transformed to a concentration related signal over the entire concentration interval, also at low concentrations, where the mV (y-axis) versus logcanalyte (x-axis) potentiometric calibration curve is not linear. In the procedure, the Ka is calculated for the interaction of cocaine with a cocaine binding aptamer and with an anti-cocaine antibody. To study the selectivity and cross-reactivity, other oligonucleotides and aptamers are tested, as well as other small ligand molecules such as tetrakis (4-chlorophenyl)borate, metergoline, lidocaine, and bromhexine. The calculated Ka compared favorably to the value reported in the literature using SPR. The potentiometric titration approach called Concentration related Response Potentiometry, is used to study molecular interaction for 7 macromolecular target molecules and 4 small molecule ligands. | ||||
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| Language | Wos | 000346683900048 | Publication Date | 2014-11-13 | |
| 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 | 6.32 | Times cited | 10 | Open Access | |
| Notes | ; Financial support for this work was provided by the University of Antwerp by granting L.J.N., K.D.W, G.V.C., and Ronny Blust a POC interdisciplinary research project. ; | Approved | Most recent IF: 6.32; 2014 IF: 5.636 | ||
| Call Number | UA @ admin @ c:irua:120164 | Serial | 5548 | ||
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| Author |
Johansson, T.B.; Van Grieken, R.E.; Nelson, J.W.; Winchester, J.W. | ||||
| Title | Elemental trace analysis of small samples by proton-induced X-ray-emission | Type | A1 Journal article | ||
| Year | 1975 | Publication | Analytical chemistry | Abbreviated Journal | |
| Volume | 47 | Issue | 6 | Pages | 855-860 |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
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| Language | Wos | A1975AA02900016 | Publication Date | 2005-03-08 | |
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| 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 | UA @ admin @ c:irua:113638 | Serial | 7895 | ||
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| 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) | ||||
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| 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 | UA @ admin @ c:irua:39871 | Serial | 5734 | ||
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| Author |
Khan, S.U.; Trashin, S.; Beltran, V.; Korostei, Y.S.; Pelmus, M.; Gorun, S.M.; Dubinina, T., V.; Verbruggen, S.W.; De Wael, K. | ||||
| Title | Photoelectrochemical behavior of phthalocyanine-sensitized TiO₂ in the presence of electron-shuttling mediators | Type | A1 Journal article | ||
| Year | 2022 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
| Volume | 94 | Issue | 37 | Pages | 12723-12731 |
| Keywords | A1 Journal article; Sustainable Energy, Air and Water Technology (DuEL); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) | ||||
| Abstract | Dye-sensitized TiO(2 )has found many applications for dye sensitized solar cells (DSSC), solar-to-chemical energy conversion, water/air purification systems, and (electro)chemical sensors. We report an electrochemical system for testing dye-sensitized materials that can be utilized in photoelectrochemical (PEC) sensors and energy conversion. Unlike related systems, the reported system does not require a direct electron transfer from semiconductors to electrodes. Rather, it relies on electron shuttling by redox mediators. A range of model photocatalytic materials were prepared using three different TiO2 materials (P25, P90, and PC500) and three sterically hindered phthalocyanines (Pcs) with electron-rich tert-butyl substituents (t-Bu4PcZn, t-Bu4PcAlCl, and t-Bu4PcH2). The materials were compared with previously developed TiO(2 )modified by electron-deficient, also sterically hindered fluorinated phthalocyanine F64PcZn, a singlet oxygen (O-1(2)) producer, as well as its metal-free derivative, F64PcH2. The PEC activity depended on the redox mediator, as well as the type of TiO2 and Pc. By comparing the responses of one-electron shuttles, such as K4Fe(CN)(4), and O-1(2)-reactive electron shuttles, such as phenol, it is possible to reveal the action mechanism of the supported photosensitizers, while the overall activity can be assessed using hydroquinone. t-Bu4PcAlCl showed significantly lower blank responses and higher specific responses toward chlorophenols compared to t-Bu4PcZn due to the electron-withdrawing effect of the Al3+ metal center. The combination of reactivity insights and the need for only microgram amounts of sensing materials renders the reported system advantageous for practical applications. | ||||
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| Language | Wos | 000855284300001 | Publication Date | 2022-09-12 | |
| 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 | 7.4 | Times cited | Open Access | OpenAccess | |
| Notes | Approved | Most recent IF: 7.4 | |||
| Call Number | UA @ admin @ c:irua:190602 | Serial | 7190 | ||
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| Author |
Lindner, H.; Autrique, D.; Garcia, C.C.; Niemax, K.; Bogaerts, A. | ||||
| Title | Optimized transport setup for high repetition rate pulse-separated analysis in laser ablation-inductively coupled plasma mass spectrometry | Type | A1 Journal article | ||
| Year | 2009 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
| Volume | 81 | Issue | 11 | Pages | 4241-4248 |
| Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract | An optimized laser ablation setup, proposed for high repetition rate inductively coupled plasma mass spectrometry (ICPMS) analyses such as 2D imaging or depth profiling, is presented. For such applications, the particle washout time needs to be as short as possible to allow high laser pulse frequencies for reduced analysis time. Therefore, it is desirable to have an ablation setup that operates as a laminar flow reactor (LFR). A top-down strategy was applied that resulted in the present design. In the first step, a previously applied ablation setup was analyzed on the basis of computational fluid dynamics (CFD) results presented by D. Autrique et al. (Spectrochim. Acta, B 2008, 63, 257−270). By means of CFD simulations, the design was modified in such a way that it operated in the LFR regime. Experimental results demonstrate that the current design can indeed be regarded as an LFR. Furthermore, the operation under LFR conditions allowed some insight into the initial radial concentration distribution if the experimental ICPMS signal and analytical expressions are taken into account. Recommendations for a modified setup for more resilient spatial distributions are given. With the present setup, a washout time of 140 ms has been achieved for a 3% signal area criterion. Therefore, 7 Hz repetition rates can be applied with the present setup. Using elementary formulas of the analytical model, an upper bound for the washout times for similar setups can be predicted. The authors believe that the presented setup geometry comes close to the achievable limit for reliable short washout times. | ||||
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| Publisher | Place of Publication | Washington, D.C. | Editor | ||
| Language | Wos | 000266601800014 | Publication Date | 2009-04-29 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0003-2700;1520-6882; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 6.32 | Times cited | 18 | Open Access | |
| Notes | Approved | Most recent IF: 6.32; 2009 IF: 5.214 | |||
| Call Number | UA @ lucian @ c:irua:76935 | Serial | 2492 | ||
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| Author |
Lindner, H.; Murtazin, A.; Groh, S.; Niemax, K.; Bogaerts, A. | ||||
| Title | Simulation and experimental studies on plasma temperature, flow velocity, and injector diameter effects for an inductively coupled plasma | Type | A1 Journal article | ||
| Year | 2011 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
| Volume | 83 | Issue | 24 | Pages | 9260-9266 |
| Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract | An inductively coupled plasma (ICP) is analyzed by means of experiments and numerical simulation. Important plasma properties are analyzed, namely, the effective temperature inside the central channel and the mean flow velocity inside the plasma. Furthermore, the effect of torches with different injector diameters is studied by the model. The temperature inside the central channel is determined from the end-on collected line-to-background ratio in dependence of the injector gas flow rates. Within the limits of 3% deviation, the results of the simulation and the experiments are in good agreement in the range of flow rates relevant for the analysis of relatively large droplets, i.e., 50 μm. The deviation increases for higher gas flow rates but stays below 6% for all flow rates studied. The velocity of the gas inside the coil region was determined by side-on analyte emission measurements with single monodisperse droplet introduction and by the analysis of the injector gas path lines in the simulation. In the downstream region significantly higher velocities were found than in the upstream region in both the simulation and the experiment. The quantitative values show good agreement in the downstream region. In the upstream region, deviations were found in the absolute values which can be attributed to the flow conditions in that region and because the methods used for velocity determination are not fully consistent. Eddy structures are found in the simulated flow lines. These affect strongly the way taken by the path lines of the injector gas and they can explain the very long analytical signals found in the experiments at low flow rates. Simulations were performed for different injector diameters in order to find conditions where good analyte transport and optimum signals can be expected. The results clearly show the existence of a transition flow rate which marks the lower limit for effective analyte transport conditions through the plasma. A rule-of-thumb equation was extracted from the results from which the transition flow rate can be estimated for different injector diameters and different injector gas compositions. | ||||
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| Publisher | Place of Publication | Washington, D.C. | Editor | ||
| Language | Wos | 000297946900013 | Publication Date | 2011-07-29 | |
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| Series Volume | Series Issue | Edition | |||
| ISSN | 0003-2700;1520-6882; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 6.32 | Times cited | 34 | Open Access | |
| Notes | Approved | Most recent IF: 6.32; 2011 IF: 5.856 | |||
| Call Number | UA @ lucian @ c:irua:94001 | Serial | 3009 | ||
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| Author |
Liu, Y.; Cánovas, R.; Crespo, G.A.; Cuartero, M. | ||||
| Title | Thin-layer potentiometry for creatinine detection in undiluted human urine using ion-exchange membranes as barriers for charged interferences | Type | A1 Journal article | ||
| Year | 2020 | Publication | Analytical Chemistry | Abbreviated Journal | Anal Chem |
| Volume | 92 | Issue | 4 | Pages | 3315-3323 |
| Keywords | A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract | Herein, thin-layer potentiometry combined with ion-exchange membranes as barriers for charged interferences is demonstrated for the analytical detection of creatinine (CRE) in undiluted human urine. Briefly, CRE diffuses through an anion-exchange membrane (AEM) from a sample contained in one fluidic compartment to a second reservoir, containing the enzyme CRE deiminase. There, CRE reacts with the enzyme, and the formation of ammonium is dynamically monitored by potentiometric ammonium-selective electrodes. This analytical concept is integrated into a lab-on-a-chip microfluidic cell that allows for a high sample throughput and the operation under stop-flow mode, which allows CRE to passively diffuse across the AEM. Conveniently, positively charged species (i.e., potassium, sodium, and ammonium, among others) are repelled by the AEM and never reach the ammonium-selective electrodes; thus, possible interference in the response can be avoided. As a result, the dynamic potential response of the electrodes is entirely ascribed to the stoichiometric formation of ammonium. The new CRE biosensor exhibits a Nernstian slope, within a linear range of response from 1 to 50 mM CRE concentration. As expected, the response time (15–60 min) primarily depends on the CRE diffusion across the AEM. CRE analysis in urine samples displayed excellent results, without requiring sample pretreatment (before the introduction of the sample in the microfluidic chip) and with high compatibility with development into a potential point-of-care clinical tool. In an attempt to decrease the analysis time, the presented analytical methodology for CRE detection is translated into an all-solid-state platform, in which the enzyme is immobilized on the surface of the ammonium-selective electrode and with the AEM on top. While more work is necessary in this direction, the CRE sensor appears to be promising for CRE analysis in both urine and blood. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | Publication Date | 2020-01-23 | ||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record | |
| Impact Factor | 7.4 | Times cited | Open Access | ||
| Notes | Approved | Most recent IF: 7.4; 2020 IF: 6.32 | |||
| Call Number | UA @ admin @ c:irua:184380 | Serial | 8667 | ||
| Permanent link to this record | |||||
| Author |
Ma, X.; Pavlidis, G.; Dillon, E.; Beltran, V.; Schwartz, J.J.; Thoury, M.; Borondics, F.; Sandt, C.; Kjoller, K.; Berrie, B.H.; Centrone, A. | ||||
| Title | Micro to nano : multiscale IR analyses reveal zinc soap heterogeneity in a 19th-century painting by Corot | Type | A1 Journal article | ||
| Year | 2022 | Publication | Analytical chemistry | Abbreviated Journal | |
| Volume | 94 | Issue | 7 | Pages | 3103-3110 |
| Keywords | A1 Journal article; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) | ||||
| Abstract | Formation and aggregation of metal carboxylates (metal soaps) can degrade the appearance and integrity of oil paints, challenging efforts to conserve painted works of art. Endeavors to understand the root cause of metal soap formation have been hampered by the limited spatial resolution of Fourier transform infrared microscopy (mu-FTIR). We overcome this limitation using optical photothermal infrared spectroscopy (O-PTIR) and photothermal-induced resonance (PTIR), two novel methods that provide IR spectra with approximate to 500 and approximate to 10 nm spatial resolutions, respectively. The distribution of chemical phases in thin sections from the top layer of a 19th-century painting is investigated at multiple scales (mu-FTIR approximate to 10(2) mu m(3), O-PTIR approximate to 10(-1) mu m(3), PTIR approximate to 10(-5) mu m(3)). The paint samples analyzed here are found to be mixtures of pigments (cobalt green, lead white), cured oil, and a rich array of intermixed, small (often << 0.1 mu m(3)) zinc soap domains. We identify Zn stearate and Zn oleate crystalline soaps with characteristic narrow IR peaks (approximate to 1530-1558 cm(-1)) and a heterogeneous, disordered, water-permeable, tetrahedral zinc soap phase, with a characteristic broad peak centered at approximate to 1596 cm(-1). We show that the high signal-to-noise ratio and spatial resolution afforded by O-PTIR are ideal for identifying phase-separated (or locally concentrated) species with low average concentration, while PTIR provides an unprecedented nanoscale view of distributions and associations of species in paint. This newly accessible nanocompositional information will advance our knowledge of chemical processes in oil paint and will stimulate new art conservation practices. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000766206700011 | Publication Date | 2022-02-09 | |
| 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 full record; WoS citing articles | |
| Impact Factor | Times cited | Open Access | OpenAccess | ||
| Notes | Approved | no | |||
| Call Number | UA @ admin @ c:irua:187380 | Serial | 8897 | ||
| 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 | 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 | UA @ admin @ c:irua:74340 | Serial | 8220 | ||
| Permanent link to this record | |||||
| Author |
Markowicz, A.A.; Storms, H.M.; Van Grieken, R.E. | ||||
| Title | Absorption correction in electron probe x-ray microanalysis of thin samples | Type | A1 Journal article | ||
| Year | 1986 | Publication | Analytical chemistry | Abbreviated Journal | |
| Volume | 58 | Issue | 7 | Pages | 1282-1285 |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract | |||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | A1986C594100007 | Publication Date | 2005-03-08 | |
| 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 | UA @ admin @ c:irua:116524 | Serial | 7409 | ||
| Permanent link to this record | |||||
| Author |
Markowicz, A.A.; Storms, H.M.; Van Grieken, R.E. | ||||
| Title | Bremsstrahlung background in electron-probe X-ray-microanalysis of thin films | Type | A1 Journal article | ||
| Year | 1985 | Publication | Analytical chemistry | Abbreviated Journal | |
| Volume | 57 | Issue | 14 | Pages | 2885-2889 |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract | |||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | A1985AVD0100033 | Publication Date | 2005-03-08 | |
| 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 | UA @ admin @ c:irua:113616 | Serial | 7567 | ||
| Permanent link to this record | |||||
| Author |
Markowicz, A.A.; Van Grieken, R.E. | ||||
| Title | Atomic number correction in electron probe X-ray microanalysis of curved samples and particles | Type | A1 Journal article | ||
| Year | 1984 | Publication | Analytical chemistry | Abbreviated Journal | |
| Volume | 56 | Issue | 14 | Pages | 2798-2801 |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract | |||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | A1984TU34600040 | Publication Date | 2005-03-08 | |
| 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 | UA @ admin @ c:irua:116519 | Serial | 7535 | ||
| Permanent link to this record | |||||
| Author |
Markowicz, A.A.; Van Grieken, R.E. | ||||
| Title | Composition dependence of Bremsstrahlung background in electron-probe x-ray microanalysis | Type | A1 Journal article | ||
| Year | 1984 | Publication | Analytical chemistry | Abbreviated Journal | |
| Volume | 56 | Issue | 12 | Pages | 2049-2051 |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract | |||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | A1984TL48800021 | Publication Date | 2005-03-08 | |
| 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 | UA @ admin @ c:irua:116518 | Serial | 7704 | ||
| Permanent link to this record | |||||
| Author |
Markowicz, A.A.; Van Grieken, R.E. | ||||
| Title | X-ray spectrometry | Type | A1 Journal article | ||
| Year | 1990 | Publication | Analytical chemistry | Abbreviated Journal | |
| Volume | 62 | Issue | 12 | Pages | 101r-113r |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract | |||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | Publication Date | 2006-11-06 | ||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record | |
| Impact Factor | Times cited | Open Access | |||
| Notes | Approved | no | |||
| Call Number | UA @ admin @ c:irua:116527 | Serial | 8779 | ||
| Permanent link to this record | |||||
| Author |
Markowicz, A.A.; Van Grieken, R.E. | ||||
| Title | X-ray spectrometry | Type | A1 Journal article | ||
| Year | 1988 | Publication | Analytical chemistry | Abbreviated Journal | |
| Volume | 60 | Issue | 12 | Pages | 28r-42r |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract | |||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | Publication Date | 2005-03-08 | ||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record | |
| Impact Factor | Times cited | Open Access | |||
| Notes | Approved | no | |||
| Call Number | UA @ admin @ c:irua:116525 | Serial | 8780 | ||
| Permanent link to this record | |||||
| Author |
Markowicz, A.A.; Van Grieken, R.E. | ||||
| Title | X-ray spectrometry | Type | A1 Journal article | ||
| Year | 1986 | Publication | Analytical chemistry | Abbreviated Journal | |
| Volume | 58 | Issue | 5 | Pages | 279r-294r |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract | |||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | Publication Date | 2005-03-08 | ||
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0003-2700; 5206-882x | ISBN | Additional Links | UA library record | |
| Impact Factor | Times cited | Open Access | |||
| Notes | Approved | no | |||
| Call Number | UA @ admin @ c:irua:116523 | Serial | 8781 | ||
| Permanent link to this record | |||||
| Author |
Martens, T.; Mihailova, D.; van Dijk, J.; Bogaerts, A. | ||||
| Title | Theoretical characterization of an atmospheric pressure glow discharge used for analytical spectrometry | Type | A1 Journal article | ||
| Year | 2009 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
| Volume | 81 | Issue | 21 | Pages | 9096-9108 |
| Keywords | A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) | ||||
| Abstract | We have investigated the plasma processes in an atmospheric pressure glow discharge (APGD) in He used for analytical spectrometry by means of fluid and Monte Carlo (MC) simulations. Typical results include the potential and electric field distributions in the plasma, the density profiles of the various plasma species throughout the discharge, the mean electron energy, as well as the rates of the various collision processes in the plasma, and the relative importance of the different production and loss rates for the various species. The similarities and differences with low-pressure glow discharges are discussed. The main differences are a very small cathode dark space region and a large positive column as well as the dominant role of molecular ions. Some characteristic features of the APGD, such as the occurrence of the different spatial zones in the discharge, are illustrated, with links to experimental observations. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Washington, D.C. | Editor | ||
| Language | Wos | 000276191900062 | Publication Date | 2009-10-08 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0003-2700;1520-6882; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 6.32 | Times cited | 15 | Open Access | |
| Notes | Approved | Most recent IF: 6.32; 2009 IF: 5.214 | |||
| Call Number | UA @ lucian @ c:irua:79554 | Serial | 3604 | ||
| Permanent link to this record | |||||
| Author |
Monico, L.; Cotte, M.; Vanmeert, F.; Amidani, L.; Janssens, K.; Nuyts, G.; Garrevoet, J.; Falkenberg, G.; Glatzel, P.; Romani, A.; Miliani, C. | ||||
| Title | Damages induced by synchrotron radiation-based X-ray microanalysis in chrome yellow paints and related Cr-compounds : assessment, quantification, and mitigation strategies | Type | A1 Journal article | ||
| Year | 2020 | Publication | Analytical Chemistry | Abbreviated Journal | Anal Chem |
| Volume | 92 | Issue | 20 | Pages | 14164-14173 |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract | Synchrotron radiation (SR)-based X-ray methods are powerful analytical tools for several purposes. They are widely used to probe the degradation mechanisms of inorganic artists' pigments in paintings, including chrome yellows (PbCr1-xSxO4; 0 <= x <= 0.8), a class of compounds often found in Van Gogh masterpieces. However, the high intensity and brightness of SR beams raise important issues regarding the potential damage inflicted on the analyzed samples. A thorough knowledge of the SR X-ray sensitivity of each class of pigment in the painting matrix is therefore required to find analytical strategies that seek to minimize the damage for preserving the integrity of the analyzed samples and to avoid data misinterpretation. Here, we employ a combination of Cr K-edge X-ray absorption near-edge structure spectroscopy, Cr-K-beta X-ray emission spectroscopy, and X-ray diffraction to monitor and quantify the effects of SR X-rays on the stability of chrome yellows and related Cr compounds and to define mitigation strategies. We found that the SR X-ray beam exposure induces changes in the oxidation state and local coordination environment of Cr ions and leads to a loss of the compound's crystalline structure. The extent of X-ray damage depends on some intrinsic properties of the samples (chemical composition of the pigment and the presence/absence and nature of the binder). It can be minimized by optimizing the overall fluence/dose released to the samples and by working in vacuum and under cryogenic conditions. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000584418100072 | Publication Date | 2020-09-21 | |
| 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; 2020 IF: 6.32 | |||
| Call Number | UA @ admin @ c:irua:174363 | Serial | 7754 | ||
| Permanent link to this record | |||||
| Author |
Monico, L.; Janssens, K.; Miliani, C.; van der Snickt, G.; Brunetti, B.G.; Guidi, M.C.; Radepont, M.; Cotte, M. | ||||
| Title | Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods : 4 : artificial aging of model samples of co-precipitates of lead chromate and lead sulfate | Type | A1 Journal article | ||
| Year | 2013 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
| Volume | 85 | Issue | 2 | Pages | 860-867 |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract | Previous investigations about the darkening of chrome yellow pigments revealed that this form of alteration is attributable to a reduction of the original Cr(VI) to Cr(III), and that the presence of sulfur-containing compounds, most often sulfates, plays a key role during this process. We recently demonstrated that different crystal forms of chrome yellow pigments (PbCrO4 and PbCr1xSxO4) are present in paintings by Vincent van Gogh. In the present work, we show how both the chemical composition and the crystalline structure of lead chromate-based pigments influence their stability. For this purpose, oil model samples made with in-house synthesized powders of PbCrO4 and PbCr1xSxO4 were artificially aged and characterized. We observed a profound darkening only for those paint models made with PbCr1xSxO4, rich in SO42 (x ≥ 0.4), and orthorhombic phases (>30 wt %). Cr and S K-edge micro X-ray absorption near edge structure investigations revealed in an unequivocal manner the formation of up to about 60% of Cr(III)-species in the outer layer of the most altered samples; conversely, independent of the paint models chemical composition, no change in the S-oxidation state was observed. Analyses employing UVvisible diffuse reflectance and Fourier transform infrared spectroscopy were performed on unaged and aged model samples in order to obtain additional information on the physicochemical changes induced by the aging treatment. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000313668400032 | Publication Date | 2012-10-10 | |
| 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 | 49 | Open Access | |
| Notes | ; This research was supported by grants from ESRF (experiment EC-799), the Interuniversity Attraction Poles Programme-Belgian Science Policy (IUAP VI/16), and the BELSPO-SDD S2-ART (SD/RI/04) project. The text also presents results from GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and FWO (Brussels, Belgium) projects G.0704.08 and G.01769.09. The EU FP7 programme CHARISMA (Grant Agreement 228330) and MIUR (PRIN08, Materiali e sistemi innovativi per la conservazione dell'arte contemporanea 2008 FFXXN9) are also acknowledged. ; | Approved | Most recent IF: 6.32; 2013 IF: 5.825 | ||
| Call Number | UA @ admin @ c:irua:110471 | Serial | 5569 | ||
| Permanent link to this record | |||||
| Author |
Monico, L.; Janssens, K.; Vanmeert, F.; Cotte, M.; Brunetti, B.G.; van der Snickt, G.; Leeuwestein, M.; Plisson, J.S.; Menu, M.; Miliani, C. | ||||
| Title | Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods : part 5 : effects of nonoriginal surface coatings into the nature and distribution of chromium and sulfur species in chrome yellow paints | Type | A1 Journal article | ||
| Year | 2014 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
| Volume | 86 | Issue | 21 | Pages | 10804-10811 |
| Keywords | A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract | The darkening of lead chromate yellow pigments, caused by a reduction of the chromate ions to Cr(III) compounds, is known to affect the appearance of several paintings by Vincent van Gogh. In previous papers of this series, we demonstrated that the darkening is activated by light and depends on the chemical composition and crystalline structure of the pigments. In this work, the results of Part 2 are extended and complemented with a new study aimed at deepening the knowledge of the nature and distribution of Cr and S species at the interface between the chrome yellow paint and the nonoriginal coating layer. For this purpose, three microsamples from two varnished paintings by Van Gogh and a waxed low relief by Gauguin (all originally uncoated) have been examined. Because nonoriginal coatings are often present in artwork by Van Gogh and contemporaries, the understanding of whether or not their application has influenced the morphological and/or physicochemical properties of the chrome yellow paint underneath is relevant in view of the conservation of these masterpieces. In all the samples studied, microscopic X-ray fluorescence (mu-XRF) and X-ray absorption near edge structure (mu-XANES) investigations showed that Cr(III)-based alteration products are present in the form of grains inside the coating (generally enriched of S species) and also homogeneously widespread at the paint surface. The distribution of Cr(III) species may be explained by the mechanical friction caused by the coating application by brush that picked up and redistributed the superficial Cr compounds, likely already present in the reduced state as result of the photodegradation process. The analysis of the XANES profiles allowed us to obtain new insights into the nature of the Cr(III) alteration products, that were identified as sulfate-, oxide-, organo-metal-, and chloride-based compounds. Building upon the knowledge acquired through the examination of original paint samples and from the investigation of aged model paints in the last Part 4 paper, in this study we aim to characterize a possible relation between the chemical composition of the coating and the chrome yellow degradation pathways by studying photochemically aged model samples covered with a dammar varnish contaminated with sulfide and sulfate salts. Cr speciation results did not show any evidence of the active role of the varnish and added S species on the reduction process of chrome yellows. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000344510200043 | Publication Date | 2014-10-10 | |
| 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 | 25 | Open Access | |
| Notes | ; This research was supported by the Italian projects PRIN (SICH) and PON (ITACHA). The text also presents results from Interuniversity Attraction Poles Programme Belgian Science Policy (S2-ART project S4DA), GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and FWO (Brussels, Belgium) projects no. G.0704.08 and G.01769.09. ESRF is acknowledged for the grants received (experiments EC-799 and EC-1051). L.M. acknowledges the CNR for the financial support received in the framework of the Short Term Mobility Programme 2013. Thanks are expressed to Ella Hendriks (Van Gogh Museum, Amsterdam) and Muriel Geldof (Cultural Heritage Agency of The Netherlands) for selecting and sharing the information on the cross-section taken from Bank of the Seine. All the staff of the Van Gogh Museum, the Kroller-Muller Museum, and the Musee d'Orsay are acknowledged for the agreeable cooperation. ; | Approved | Most recent IF: 6.32; 2014 IF: 5.636 | ||
| Call Number | UA @ admin @ c:irua:122100 | Serial | 5570 | ||
| Permanent link to this record | |||||
| 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 | UA @ admin @ c:irua:88795 | Serial | 5571 | ||
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| Author |
Monico, L.; van der Snickt, G.; Janssens, K.; de Nolf, W.; Miliani, C.; Verbeeck, J.; Tian, H.; Tan, H.; Dik, J.; Radepont, M.; Cotte, M. | ||||
| Title | Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of synchrotron X-ray spectromicroscopy and related methods : 1 : artificially aged model samples | Type | A1 Journal article | ||
| Year | 2011 | Publication | Analytical chemistry | Abbreviated Journal | Anal Chem |
| Volume | 83 | Issue | 4 | Pages | 1214-1223 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) | ||||
| Abstract | On several paintings by artists of the end of the 19th century and the beginning of the 20th Century a darkening of the original yellow areas, painted with the chrome yellow pigment (PbCrO4, PbCrO4·xPbSO4, or PbCrO4·xPbO) is observed. The most famous of these are the various Sunflowers paintings Vincent van Gogh made during his career. In the first part of this work, we attempt to elucidate the degradation process of chrome yellow by studying artificially aged model samples. In view of the very thin (1−3 μm) alteration layers that are formed, high lateral resolution spectroscopic methods such as microscopic X-ray absorption near edge (μ-XANES), X-ray fluorescence spectrometry (μ-XRF), and electron energy loss spectrometry (EELS) were employed. Some of these use synchrotron radiation (SR). Additionally, microscopic SR X-ray diffraction (SR μ-XRD), μ-Raman, and mid-FTIR spectroscopy were employed to completely characterize the samples. The formation of Cr(III) compounds at the surface of the chrome yellow paint layers is particularly observed in one aged model sample taken from a historic paint tube (ca. 1914). About two-thirds of the chromium that is present at the surface has reduced from the hexavalent to the trivalent state. The EELS and μ-XANES spectra are consistent with the presence of Cr2O3·2H2O (viridian). Moreover, as demonstrated by μ-XANES, the presence of another Cr(III) compound, such as either Cr2(SO4)3·H2O or (CH3CO2)7Cr3(OH)2 [chromium(III) acetate hydroxide], is likely. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Washington, D.C. | Editor | ||
| Language | Wos | 000287176900011 | Publication Date | 2011-02-14 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 0003-2700;1520-6882; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 6.32 | Times cited | 113 | Open Access | |
| Notes | Iuap; Fwo | Approved | Most recent IF: 6.32; 2011 IF: 5.856 | ||
| Call Number | UA @ lucian @ c:irua:88794UA @ admin @ c:irua:88794 | Serial | 632 | ||
| Permanent link to this record | |||||