| Records |
| Author |
Bogaerts, A. |
| Title |
Modeling plasmas in analytical chemistry—an example of cross-fertilization |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Analytical And Bioanalytical Chemistry |
Abbreviated Journal |
Anal Bioanal Chem |
| Volume |
412 |
Issue |
24 |
Pages |
6059-6083 |
Keywords  |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
This paper gives an overview of the modeling work developed in our group in the last 25 years for various plasmas used in analytical spectrochemistry, i.e., glow discharges (GDs), inductively coupled plasmas (ICPs), and laser ablation (LA) for sample introduction in the ICP and for laser-induced breakdown spectroscopy (LIBS). The modeling approaches are briefly presented, which are different for each case, and some characteristic results are illustrated. These plasmas are used not only in analytical chemistry but also in other applications, and the insights obtained in these other fields were quite helpful for us to develop models for the analytical plasmas. Likewise, there is now a huge interest in plasma–liquid interaction, atmospheric pressure glow discharges (APGDs), and dielectric barrier discharges (DBDs) for environmental, medical, and materials applications of plasmas. The insights obtained in these fields are also very relevant for ambient desorption/ionization sources and for liquid sampling, which are nowadays very popular in analytical chemistry, and they could be very helpful in developing models for these sources as well. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000522701700005 |
Publication Date |
2020-03-31 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
|
| ISSN |
1618-2642 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.3 |
Times cited |
|
Open Access |
|
| Notes |
M. Aghaei, Z. Chen, D. Autrique, T. Martens, and P. Heirman are gratefully acknowledged for their valuable efforts in the model developments illustrated in this paper. |
Approved |
Most recent IF: 4.3; 2020 IF: 3.431 |
| Call Number |
PLASMANT @ plasmant @c:irua:168600 |
Serial |
6412 |
| Permanent link to this record |
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| |
| Author |
Aghaei, M.; Bogaerts, A. |
| Title |
Flowing Atmospheric Pressure Afterglow for Ambient Ionization: Reaction Pathways Revealed by Modeling |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
93 |
Issue |
17 |
Pages |
6620-6628 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
We describe the plasma chemistry in a helium flowing atmospheric pressure afterglow (FAPA) used for analytical spectrometry, by means of a quasione-dimensional (1D) plasma chemical kinetics model. We study the effect of typical impurities present in the feed gas, as well as the afterglow in ambient humid air. The model provides the species density profiles in the discharge and afterglow regions and the chemical pathways. We demonstrate that H, N, and O atoms are formed in the discharge region, while the dominant reactive neutral species in the afterglow are O3 and NO. He* and He2* are responsible for Penning ionization of O2, N2, H2O, H2, and N, and especially O and H atoms. Besides, He2+ also contributes to ionization of N2, O2, H2O, and O through charge transfer reactions. From the pool of ions created in the discharge, NO+ and (H2O)3H+ are the dominant ions in the afterglow. Moreover, negatively charged clusters, such as NO3H2O− and NO2H2O−, are formed and their pathway is discussed as well. Our model predictions are in line with earlier observations in the literature about the important reagent ions and provide a comprehensive overview of the underlying pathways. The model explains in detail why helium provides a high analytical sensitivity because of high reagent ion formation by both Penning ionization and charge transfer. Such insights are very valuable for improving the analytical performance of this (and other) ambient desorption/ionization source(s). |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000648505900008 |
Publication Date |
2021-05-04 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
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Edition |
|
| ISSN |
0003-2700 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.32 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
Fonds Wetenschappelijk Onderzoek, 6713 ; The authors gratefully acknowledge financial support from the Fonds voor Wetenschappelijk Onderzoek (FWO) grant number 6713. The computational work was carried out using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen (UA), a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (Department EWI), and the UA. The authors also thank J. T. Shelley for providing experimental data for the gas velocity behind the anode disk and before the mass spectrometer interface, to validate our model. |
Approved |
Most recent IF: 6.32 |
| Call Number |
PLASMANT @ plasmant @c:irua:178126 |
Serial |
6762 |
| Permanent link to this record |
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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. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000805334400013 |
Publication Date |
2022-03-28 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| 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 |
| Permanent link to this record |
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| Author |
Sleegers, N.; van Nuijs, A.L.N.; van den Berg, M.; De Wael, K. |
| Title |
Cephalosporin antibiotics : electrochemical fingerprints and core structure reactions investigated by LC-MSMS |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
91 |
Issue |
3 |
Pages |
2035-2041 |
| Keywords |
A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre |
| Abstract |
Electrochemistry and exploiting electrochemical fingerprints is a potent approach to address newly emerging surveillance needs, for instance for antibiotics. However, a comprehensive insight in the electrochemical oxidation behaviour and mechanism is re-quired for this sensing strategy. To address the lack in knowledge of the voltammetric behaviour of the cephalosporins antibiotics, a selection of cephalosporin antibiotics and two main intermediates were subjected to an electrochemical study of their redox behaviour by means of pulsed voltammetric techniques and small-scale electrolysis combined with HPLC-MS/MS analyses. Sur-prisingly, the detected oxidation products did not fit the earlier suggested oxidation of the sulfur group to the corresponding sul-foxide. The influence of different side chains, both at the three and the seven position of the β-lactam core structure on the elec-trochemical fingerprint were investigated. Additional oxidation signals at lower potentials were elucidated and linked to different side chains. These signals were further exploited to allow simultaneous detection of different cephalosporins in one voltammetric sweep. These fundamental insights can become the building blocks for an new on-site screening method. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000458220300055 |
Publication Date |
2019-01-03 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
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Edition |
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| ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.32 |
Times cited |
6 |
Open Access |
|
| Notes |
; The authors acknowledge financial support from the Fund for Scientific Research (FWO) Flanders, Grant 1S 37658 17N. ; |
Approved |
Most recent IF: 6.32 |
| Call Number |
UA @ admin @ c:irua:156046 |
Serial |
5497 |
| Permanent link to this record |
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| |
| Author |
Ranjbari, E.; Hadjmohammadi, M.R.; Kiekens, F.; De Wael, K. |
| Title |
Mixed hemi/ad-micelle sodium dodecyl sulfate-coated magnetic iron oxide nanoparticles for the efficient removal and trace determination of rhodamine-B and rhodamine-6G |
Type |
A1 Journal article |
| Year |
2015 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
87 |
Issue |
15 |
Pages |
7894-7901 |
| Keywords |
A1 Journal article; Pharmacology. Therapy; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Mixed hemi/ad-micelle sodium dodecyl sulfate (SDS)-coated magnetic iron oxide nanoparticles (MHAMS-MIONPs) were used as an efficient adsorbent for both removal and preconcentration of two important carcinogenic xanthine dyes named rhodamine-B (RB) and rhodamine-6G (RG). To gain insight in the configuration of SDS molecules on the surface of MIONPs, zeta potential measurements were performed in different [SDS]/[MIONP] ratios. Zeta potential data indicated that mixed hemi/ad-micelle MHAM was formed in [SDS]/[MIONP] ratios over the range of 1.1 to 7.3. Parameters affecting the adsorption of dyes were optimized as removal efficiency by one variable at-a-time and response surface methodology; the obtained removal efficiencies were ∼100%. Adsorption kinetic and equilibrium studies, under the optimum condition (pH = 2; amount of MIONPs = 87.15 mg; [SDS]/[MIONP] ratio = 2.9), showed that adsorption of both dyes are based on the pseudo-second-order and the Langmuir isotherm models, respectively. The maximum adsorption capacities for RB and RG were 385 and 323 mg g1, respectively. MHAMS-MIONPs were also applied for extraction of RB and RG. Under optimum conditions (pH = 2; amount of damped MHAMS-MIONPs = 90 mg; eluent solvent volume = 2.6 mL of 3% acetic acid in acetonitrile), extraction recoveries for 0.5 mg L1 of RB and RG were 98% and 99%, with preconcentration factors of 327 and 330, respectively. Limit of detection obtained for rhodamine dyes were <0.7 ng mL1. Finally, MHAMS-MIONPs were successfully applied for both removal and trace determination of RB and RG in environmental and wastewater samples. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000359277900056 |
Publication Date |
2015-07-08 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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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 |
6.32 |
Times cited |
36 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 6.32; 2015 IF: 5.636 |
| Call Number |
UA @ admin @ c:irua:126583 |
Serial |
5730 |
| Permanent link to this record |
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| Author |
Neven, L.; Barich, H.; Ching, H.Y.V.; Khan, S.U.; Colomier, C.; Patel, H.H.; Gorun, S.M.; Verbruggen, S.; Van Doorslaer, S.; De Wael, K. |
| Title |
Correlation between the fluorination degree of perfluorinated zinc phthalocyanines, their singlet oxygen generation ability, and their photoelectrochemical response for phenol sensing |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
94 |
Issue |
13 |
Pages |
5221-5230 |
| Keywords |
A1 Journal article; Organic synthesis (ORSY); Sustainable Energy, Air and Water Technology (DuEL); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
| Abstract |
Electron-withdrawing perfluoroalkyl peripheral groups grafted on phthalocyanine (Pc) macrocycles improve their single-site isolation, solubility, and resistance to self-oxidation, all beneficial features for catalytic applications. A high degree of fluorination also enhances the reducibility of Pcs and could alter their singlet oxygen (1O2) photoproduction. The ethanol/toluene 20:80 vol % solvent mixture was found to dissolve perfluorinated FnPcZn complexes, n = 16, 52, and 64, and minimize the aggregation of the sterically unencumbered F16PcZn. The 1O2 production ability of FnPcZn complexes was examined using 9,10-dimethylanthracene (DMA) and 2,2,6,6-tetramethylpiperidine (TEMP) in combination with UV–vis and electron paramagnetic resonance (EPR) spectroscopy, respectively. While the photoreduction of F52PcZn and F64PcZn in the presence of redox-active TEMP lowered 1O2 production, DMA was a suitable 1O2 trap for ranking the complexes. The solution reactivity was complemented by solid-state studies via the construction of photoelectrochemical sensors based on TiO2-supported FnPcZn, FnPcZn|TiO2. Phenol photo-oxidation by 1O2, followed by its electrochemical reduction, defines a redox cycle, the 1O2 production having been found to depend on the value of n and structural features of the supported complexes. Consistent with solution studies, F52PcZn was found to be the most efficient 1O2 generator. The insights on reactivity testing and structural–activity relationships obtained may be useful for designing efficient and robust sensors and for other 1O2-related applications of FnPcZn. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000786254500002 |
Publication Date |
2022-03-22 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
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Edition |
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| 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:187522 |
Serial |
7141 |
| Permanent link to this record |
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| Author |
Rahemi, V.; Trashin, S.; Hafideddine, Z.; Van Doorslaer, S.; Meynen, V.; Gorton, L.; De Wael, K. |
| Title |
Amperometric flow-injection analysis of phenols induced by reactive oxygen species generated under daylight irradiation of titania impregnated with horseradish peroxidase |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
92 |
Issue |
92 |
Pages |
3643-3649 |
| Keywords |
A1 Journal article; Laboratory of adsorption and catalysis (LADCA); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Titanium dioxide (TiO2) is a unique material for biosensing applications due to its capability of hosting enzymes. For the first time, we show that TiO2 can accumulate reactive oxygen species (ROS) under daylight irradiation and can support the catalytic cycle of horseradish peroxidase (HRP) without the need of H2O2 to be present in the solution. Phenolic compounds, such as hydroquinone (HQ) and 4-aminophenol (4-AP), were detected amperometrically in flow-injection analysis (FIA) mode via the use of an electrode modified with TiO2 impregnated with HRP. In contrast to the conventional detection scheme, no H2O2 was added to the analyte solution. Basically, the inherited ability of TiO2 to generate reactive oxygen species is used as a strategy to avoid adding H2O2 in the solution during the detection of phenolic compounds. Electron paramagnetic resonance (EPR) spectroscopy indicates the presence of ROS on titania which, in interaction with HRP, initiate the electrocatalysis toward phenolic compounds. The amperometric response to 4-AP was linear in the concentration range between 0.05 and 2 μM. The sensitivity was 0.51 A M–1 cm–2, and the limit of detection (LOD) 26 nM. The proposed sensor design opens new opportunities for the detection of phenolic traces by HRP-based electrochemical biosensors, yet in a more straightforward and sensitive way following green chemistry principles of avoiding the use of reactive and harmful chemical, such as H2O2. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000518234700023 |
Publication Date |
2020-01-27 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
7.4 |
Times cited |
3 |
Open Access |
|
| Notes |
; The authors thank Scientific Reseatch-Flanders (F-WO) (grant 12T4219N) for funding. ; |
Approved |
Most recent IF: 7.4; 2020 IF: 6.32 |
| Call Number |
UA @ admin @ c:irua:166241 |
Serial |
5463 |
| Permanent link to this record |
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| Author |
Schram, J.; Parrilla, M.; Sleegers, N.; Samyn, N.; Bijvoets, S.M.; Heerschop, M.W.J.; van Nuijs, A.L.N.; De Wael, K. |
| Title |
Identifying Electrochemical Fingerprints of Ketamine with Voltammetry and Liquid Chromatography–Mass Spectrometry for Its Detection in Seized Samples |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
92 |
Issue |
19 |
Pages |
13485-13492 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre |
| Abstract |
Herein, a straightforward electrochemical approach for the determination of ketamine in street samples and seizures is presented by employing screen-printed electrodes (SPE). Square wave voltammetry (SWV) is used to study the electrochemical behavior of the illicit drug, thus profiling the different oxidation states of the substance at different pHs. Besides, the oxidation pathway of ketamine on SPE is investigated for the first time with liquid chromatography–high-resolution mass spectrometry. Under the optimized conditions, the calibration curve of ketamine at buffer solution (pH 12) exhibits a sensitivity of 8.2 μA μM–1, a linear relationship between 50 and 2500 μM with excellent reproducibility (RSD = 2.2%, at 500 μM, n = 7), and a limit of detection (LOD) of 11.7 μM. Subsequently, binary mixtures of ketamine with adulterants and illicit drugs are analyzed with SWV to investigate the electrochemical fingerprint. Moreover, the profile overlapping between different substances is addressed by the introduction of an electrode pretreatment and the integration of a tailor-made script for data treatment. Finally, the approach is tested on street samples from forensic seizures. Overall, this system allows for the on-site identification of ketamine by law enforcement agents in an easy-to-use and rapid manner on cargos and seizures, thereby disrupting the distribution channel and avoiding the illicit drug reaching the end-user. |
| Address |
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| Corporate Author |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000580426800091 |
Publication Date |
2020-10-06 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0003-2700 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
7.4 |
Times cited |
|
Open Access |
|
| Notes |
Universiteit Antwerpen; H2020 Societal Challenges, 833787 ; Fonds Wetenschappelijk Onderzoek, 1S3765817N 1SB8120N ; |
Approved |
Most recent IF: 7.4; 2020 IF: 6.32 |
| Call Number |
AXES @ axes @c:irua:170523 |
Serial |
6435 |
| Permanent link to this record |
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| Author |
Barich, H.; Cánovas, R.; De Wael, K. |
| Title |
Electrochemical identification of hazardous phenols and their complex mixtures in real samples using unmodified screen-printed electrodes |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Journal of electroanalytical chemistry : an international journal devoted to all aspects of electrode kynetics, interfacial structure, properties of electrolytes, colloid and biological electrochemistry. |
Abbreviated Journal |
J Electroanal Chem |
| Volume |
904 |
Issue |
|
Pages |
115878 |
| Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
| Abstract |
The electrochemical behavior of some of the most relevant endocrine-disrupting phenols using unmodified carbon screen-printed electrodes (SPEs) is described for the first time. Experiments were made to assess the electrochemical behavior of phenol (PHOH), pentachlorophenol (PCP), 4-tert octylphenol (OP) and bisphenol A (BPA) and their determination in the most favorable conditions, using voltammetric methods such as cyclic voltammetry (CV), linear sweep voltammetry (LSV) and square wave voltammetry (SWV) in Britton Robinson (BR) buffer. Further, the usefulness of the electrochemical approach was validated with real samples from a local river and was compared to commercial phenols test kit, which is commonly used for on-site screening in industrial streams and wastewaters. Finally, the approach was compared with a lab-bench standard method using real samples, i.e., high-performance liquid chromatography with a photodiode array detector (HPLC-DAD). |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000741151200005 |
Publication Date |
2021-11-14 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
1572-6657; 1873-2569 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.5 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
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Approved |
Most recent IF: 4.5 |
| Call Number |
UA @ admin @ c:irua:184384 |
Serial |
7150 |
| Permanent link to this record |
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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 |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
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Publication Date |
2020-01-23 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record |
| Impact Factor |
7.4 |
Times cited |
|
Open Access |
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| 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 |
Rahemi, V.; Sarmadian, N.; Anaf, W.; Janssens, K.; Lamoen, D.; Partoens, B.; De Wael, K. |
| Title |
Unique opto-electronic structure and photo reduction properties of sulfur doped lead chromates explaining their instability in paintings |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
89 |
Issue |
89 |
Pages |
3326-3334 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Chrome yellow refers to a group of synthetic inorganic pigments that became popular as an artists material from the second quarter of the 19th century. The color of the pigment, in which the chromate ion acts as a chromophore, is related to its chemical composition (PbCr1-xSxO4, with 0≤x≤0.8) and crystalline structure (monoclinic/orthorhombic). Their shades range from the yellow-orange to the paler yellow tones with increasing sulfate amount. These pigments show remarkable signs of degradation after limited time periods. Pure PbCrO4 (crocoite in its natural form) has a deep yellow color and is relatively stable, while the co-precipitate with lead sulfate (PbCr1-xSxO4) has a paler shade and seems to degrade faster. This degradation is assumed to be related to the reduction of Cr(VI) to Cr(III). We show that on increasing the sulfur(S)-content in chrome yellow, the band gap increases. Typically, when increasing the band gap, one might assume that a decrease in photo activity is the result. However, the photo activity relative to the Cr content, and thus Cr reduction, of sulfur-rich PbCr1-xSxO4 is found to be much higher compared to the sulfur-poor or non-doped lead chromates. This discrepancy can be explained by the evolution of the crystal and electronic structure as function of the sulfur content: first-principles density functional theory calculations show that both the absorption coefficient and reflection coefficients of the lead chromates change as a result of the sulfate doping in such a way that the generation of electron-hole pairs under illumination relative to the total Cr content increases. These changes in the material properties explain why paler shade yellow colors of this pigment are more prone to discoloration. The electronic structure calculations also demonstrate that lead chromate and its co-precipitates are p-type semiconductors, which explains the observed reduction reaction. As understanding this phenomenon is valuable in the field of cultural heritage, this study is the first joint action of photo-electrochemical measurements and first-principles calculations to approve the higher tendency of sulfur-rich lead chromates to darken. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
|
Wos |
000397478300015 |
Publication Date |
2017-02-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-2700 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.32 |
Times cited |
7 |
Open Access |
OpenAccess |
| Notes |
; The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government, department EWI. The BOF-GOA action SOLARPAINT of the University of Antwerp Research Council is acknowledged for financial support. W.A. acknowledges support from BELSPO project S2-ART. Dr. L. Monico and Dr. C. Miliani (ISTM, Perugia) are gratefully acknowledged for helpful discussions and for providing some of the initial batches of the materials studied. ; |
Approved |
Most recent IF: 6.32 |
| Call Number |
UA @ lucian @ c:irua:140886 |
Serial |
4451 |
| Permanent link to this record |
| |
|
| |
| Author |
Monico, L.; Janssens, K.; Miliani, C.; Brunetti, B.G.; Vagnini, M.; Vanmeert, F.; Falkenberg, G.; Abakumov, A.; Lu, Y.; Tian, H.; Verbeeck, J.; Radepont, M.; Cotte, M.; Hendriks, E.; Geldof, M.; van der Loeff, L.; Salvant, J.; Menu, M.; |
| Title |
Degradation process of lead chromate in paintings by Vincent van Gogh studied by means of spectromicroscopic methods : 3 : synthesis, characterization, and detection of different crystal forms of the chrome yellow pigment |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
85 |
Issue |
2 |
Pages |
860-867 |
| Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
The painter, Vincent van Gogh, and some of his contemporaries frequently made use of the pigment chrome yellow that is known to show a tendency toward darkening. This pigment may correspond to various chemical compounds such as PbCrO4 and PbCr1-xSxO4, that may each be present in various crystallographic forms with different tendencies toward degradation. Investigations by X-ray diffraction (XRD), mid-Fourier Transform infrared (FTIR), and Raman instruments (benchtop and portable) and synchrotron radiation-based micro-XRD and X-ray absorption near edge structure spectroscopy performed on oil-paint models, prepared with in-house synthesized PbCrO4 and PbCr1-xSxO4, permitted us to characterize the spectroscopic features of the various forms. On the basis of these results, an extended study has been carried out on historic paint tubes and on embedded paint microsamples taken from yellow-orange/pale yellow areas of 12 Van Gogh paintings, demonstrating that Van Gogh effectively made use of different chrome yellow types. This conclusion was also confirmed by in situ mid-FTIR investigations on Van Goghs Portrait of Gauguin (Van Gogh Museum, Amsterdam). |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
| Language |
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Wos |
000313668400031 |
Publication Date |
2012-10-10 |
| 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 |
79 |
Open Access |
|
| Notes |
Goa; Fwo |
Approved |
Most recent IF: 6.32; 2013 IF: 5.825 |
| Call Number |
UA @ lucian @ c:irua:108707UA @ admin @ c:irua:108707 |
Serial |
631 |
| Permanent link to this record |
| |
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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. |
| Address |
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| Corporate Author |
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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 |
| |
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| |
| Author |
De Jong, M.; Sleegers, N.; Florea, A.; Van Loon, J.; van Nuijs, A.L.N.; Samyn, N.; De Wael, K. |
| Title |
Unraveling the mechanisms behind the complete suppression of cocaine electrochemical signals by chlorpromazine, promethazine, procaine, and dextromethorphan |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
91 |
Issue |
24 |
Pages |
15453-15460 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre; Product development |
| Abstract |
The present work investigates the challenges accompanied by the electrochemical cocaine detection in physiological conditions (pH 7) in the presence of chlorpromazine, promethazine, procaine, and dextromethorphan, frequently used cutting agents in cocaine street samples. The problem translates into the absence of the cocaine oxidation signal (signal suppression) when in a mixture with one of these compounds, leading to false negative results. Although a solution to this problem was provided through earlier experiments of our group, the mechanisms behind the suppression are now fundamentally investigated via electrochemical and liquid chromatography quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) strategies. The latter was used to confirm the passivation of the electrodes due to their interaction with promethazine and chlorpromazine. Electron transfer mechanisms were further identified via linear sweep voltammetry. Next, adsorption experiments were performed on the graphite screen printed electrodes both with and without potential assistance in order to confirm if the suppression of the cocaine signals is due to passivation induced by the cutting agents or their oxidized products. The proposed strategies allowed us to identify the mechanisms of cocaine suppression for each cutting agent mentioned. Suppression due to procaine and dextromethorphan is caused by fouling of the electrode surface by their oxidized forms, while for chlorpromazine and promethazine the suppression of the cocaine signal is related to the strong adsorption of these (nonoxidized) cutting agents onto the graphite electrode surface. These findings provide fundamental insights in possible suppression and other interfering mechanisms using electrochemistry in general not only in the drug detection sector. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000503910600018 |
Publication Date |
2019-11-14 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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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 |
6.32 |
Times cited |
|
Open Access |
|
| Notes |
; The authors acknowledge financial support from IOF-SBO/POC (UAntwerp) and the Fund for Scientific Research (FWO) Flanders, Grant 1S 37658 17N. ; |
Approved |
Most recent IF: 6.32 |
| Call Number |
UA @ admin @ c:irua:165727 |
Serial |
5887 |
| Permanent link to this record |
| |
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| |
| Author |
De Jong, M.; Florea, A.; de Vries, A.-M.; van Nuijs, A.L.N.; Covaci, A.; Van Durme, F.; Martins, J.C.; Samyn, N.; De Wael, K. |
| Title |
Levamisole : a common adulterant in cocaine street samples hindering electrochemical detection of cocaine |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
90 |
Issue |
8 |
Pages |
5290-5297 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre |
| Abstract |
The present work investigates the electrochemical determination of cocaine in the presence of levamisole, one of the most common adulterants found in cocaine street samples. Levamisole misleads cocaine color tests, giving a blue color (positive test) even in the absence of cocaine. Moreover, the electrochemical detection of cocaine is also affected by the presence of levamisole, with a suppression of the oxidation signal of cocaine. When levamisole is present in the sample in ratios higher than 1:1, the cocaine signal is no longer detected, thus leading to false negative results. Mass spectrometry and nuclear magnetic resonance were used to investigate if the signal suppression is due to the formation of a complex between cocaine and levamisole in bulk solution. Strategies to eliminate this suppressing effect are further suggested in this manuscript. In a first approach, the increase of the pH of the sample solution from pH 7 to pH 12 allowed the voltammetric determination of cocaine in the presence of levamisole in a concentration range from 10 to 5000 μM at nonmodified graphite disposable electrodes with a detection limit of 5 μM. In a second approach, the graphite electrode was cathodically pretreated, resulting in the presence of oxidation peaks of both cocaine and levamisole, with a detection limit for cocaine of 3 μM over the linear range of concentrations from 10 to 2500 μM. Both these strategies have been successfully applied for the simultaneous detection of cocaine and levamisole in three street samples on unmodified graphite disposable electrodes. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
|
| Language |
|
Wos |
000430512200049 |
Publication Date |
2018-02-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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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 |
6.32 |
Times cited |
8 |
Open Access |
|
| Notes |
; This project has received funding from the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement No. 753223 Narcoreader. This work was also supported by BR/314/PI/ APTADRU Project and IOF-SBO (UAntwerp). Alexander van Nuijs acknowledges the Research Foundation-Flanders (FWO) for his postdoctoral fellowship. ; |
Approved |
Most recent IF: 6.32 |
| Call Number |
UA @ admin @ c:irua:149528 |
Serial |
5693 |
| Permanent link to this record |
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| |
| Author |
Sleegers, N.; van Nuijs, A.L.N.; van den Berg, M.; De Wael, K. |
| Title |
Electrochemistry of intact versus degraded cephalosporin antibiotics facilitated by LC–MS analysis |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
93 |
Issue |
4 |
Pages |
2394-2402 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre |
| Abstract |
The electrochemical detection of cephalosporins is a promising approach for the monitoring of cephalosporin levels in process waters. However, this class of antibiotics, like penicillins, is composed of chemically active molecules and susceptible to hydrolysis and aminolysis of the four membered β-lactam ring present. In order to develop a smart monitoring strategy for cephalosporins, the influence of degradation (hydrolysis and aminolysis) on the electrochemical fingerprint has to be taken into account. Therefore, an investigation was carried out to understand the changes of the voltammetric fingerprints upon acidic and alkaline degradation. Changes in fingerprints were correlated to the degradation pathways through the combination of square wave voltammetry and liquid chromatography quadrupole time-of-flight analysis. The characteristic electrochemical signals of the β-lactam ring disappeared upon hydrolysis. Additional oxidation signals that appeared after degradation were elucidated and linked to different degradation products, and therefore, enrich the voltammetric fingerprints with information of the state of the cephalosporins. The applicability of the electrochemical monitoring system was explored by the analysis of the intact and degraded industrial process waters containing the key intermediate 7-aminodeacetoxycephalosporanic acid (7-ADCA). Clearly, the intact process samples exhibited the expected core signals of 7-ADCA and could be quantified, while the degraded samples only showed the newly formed degradation products. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000618089100063 |
Publication Date |
2021-01-04 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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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 |
6.32 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 6.32 |
| Call Number |
UA @ admin @ c:irua:176206 |
Serial |
7864 |
| Permanent link to this record |
| |
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| |
| Author |
Alvarez-Martin, A.; Newsome, G.A.; Janssens, K. |
| Title |
High-resolution mass spectrometry and nontraditional mass defect analysis of brominated historical pigments |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
93 |
Issue |
44 |
Pages |
14851-14858 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp X-ray Imaging and Spectroscopy (AXIS) |
| Abstract |
The implementation of high-resolution mass spectrometry systems offers new possibilities for the analysis of complex art samples such as historical oil paintings. However, these multicomponent systems generate large and complex data sets that require advanced visualization tools to aid interpretation, especially when no chromatographic separation is performed. In the context of this research, it was crucial to propose a data analysis tool to identify the products generated during the synthesis, drying, and aging of historical pigments. This study reports for the first time a nontraditional mass defect analysis of oil paint samples containing a fugitive brominated-organic pigment, eosin or geranium lake, by using direct infusion electrospray ionization in combination with a high-resolution Orbitrap mass spectrometer. The use of nontraditional Kendrick mass defect plots is presented in this study as a processing and visualization tool to recognize brominated species based on their specific mass defect and isotope pattern. The results demonstrate that this approach could provide valuable molecular compositional information on the degradation pathways of this pigment. We anticipate that mass defect analysis will become highly relevant in future degradation studies of many more historical organic pigments. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
|
Wos |
000718171600037 |
Publication Date |
2021-10-29 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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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 |
6.32 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 6.32 |
| Call Number |
UA @ admin @ c:irua:182347 |
Serial |
8038 |
| Permanent link to this record |
| |
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| |
| Author |
Drăgan, A.-M.; Parrilla, M.; Feier, B.; Oprean, R.; Cristea, C.; De Wael, K. |
| Title |
Analytical techniques for the detection of amphetamine-type substances in different matrices : a comprehensive review |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Trac-Trends In Analytical Chemistry |
Abbreviated Journal |
Trac-Trend Anal Chem |
| Volume |
145 |
Issue |
|
Pages |
116447 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
| Abstract |
This current review focuses on contributions to amphetamine-type substances (ATS) analysis. This type of synthetic illicit drugs has been increasingly present worldwide reaching 5% of the market on illicit drugs in 2019. The increment of their production in many clandestine laboratories and easy distribution among society are two of the main concerns towards the battle against synthetic drugs. Therefore, the first part of this review details the classification and mechanism of action of ATS in the human body. Second, the pharmacological and toxicological effects of ATS on human health are described to motivate the need of early detection of ATS. Subsequently, the most used laboratory-based and portable methods are presented and critically discussed along the review. Finally, a careful discussion on the advantages and disadvantages of portable techniques employed on the field are addressed as potential tools for on-site ATS detection by law enforcement officers. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000723747000009 |
Publication Date |
2021-09-30 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0165-9936; 1879-3142 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
8.442 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 8.442 |
| Call Number |
UA @ admin @ c:irua:183268 |
Serial |
7460 |
| Permanent link to this record |
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| |
| Author |
Trashin, S.; Morales-Yánez, F.; Thiruvottriyur Shanmugam, S.; Paredis, L.; Carrión, E.N.; Sariego, I.; Muyldermans, S.; Polman, K.; Gorun, S.M.; De Wael, K. |
| Title |
Nanobody-based immunosensor detection enhanced by photocatalytic-electrochemical redox cycling |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
93 |
Issue |
40 |
Pages |
13606-13614 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
| Abstract |
Detection of antigenic biomarkers present in trace amounts is of crucial importance for medical diagnosis. A parasitic disease, human toxocariasis, lacks an adequate diagnostic method despite its worldwide occurrence. The currently used serology tests may stay positive even years after a possibly unnoticed infection, whereas the direct detection of a re-infection or a still active infection remains a diagnostic challenge due to the low concentration of circulating parasitic antigens. We report a time-efficient sandwich immunosensor using small recombinant single-domain antibodies (nanobodies) derived from camelid heavy-chain antibodies specific to Toxocara canis antigens. An enhanced sensitivity to pg/mL levels is achieved by using a redox cycle consisting of a photocatalytic oxidation and electrochemical reduction steps. The photocatalytic oxidation is achieved by a photosensitizer generating singlet oxygen (1O2) that, in turn, readily reacts with p-nitrophenol enzymatically produced under alkaline conditions. The photooxidation produces benzoquinone that is electrochemically reduced to hydroquinone, generating an amperometric response. The light-driven process could be easily separated from the background, thus making amperometric detection more reliable. The proposed method for detection of the toxocariasis antigen marker shows superior performances compared to other detection schemes with the same nanobodies and outperforms by at least two orders of magnitude the assays based on regular antibodies, thus suggesting new opportunities for electrochemical immunoassays of challenging low levels of antigens. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000708550500025 |
Publication Date |
2021-09-29 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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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 |
6.32 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 6.32 |
| Call Number |
UA @ admin @ c:irua:181795 |
Serial |
8290 |
| Permanent link to this record |
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| |
| Author |
Ortiz-Aguayo, D.; De Wael, K.; del Valle, M. |
| Title |
Voltammetric sensing using an array of modified SPCE coupled with machine learning strategies for the improved identification of opioids in presence of cutting agents |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Journal Of Electroanalytical Chemistry |
Abbreviated Journal |
J Electroanal Chem |
| Volume |
902 |
Issue |
|
Pages |
115770 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
| Abstract |
This work reports the use of modified screen-printed carbon electrodes (SPCEs) for the identification of three drugs of abuse and two habitual cutting agents, caffeine and paracetamol, combining voltammetric sensing and chemometrics. In order to achieve this goal, codeine, heroin and morphine were subjected to Square Wave Voltammetry (SWV) at pH 7, in order to elucidate their electrochemical fingerprints. The optimized SPCEs electrode array, which have a differentiated response for the three oxidizable compounds, was derived from Carbon, Prussian blue, Cobalt (II) phthalocyanine, Copper (II) oxide, Polypyrrole and Palladium nanoparticles ink-modified carbon electrodes. Finally, Principal Component Analysis (PCA) coupled with Silhouette parameter assessment was used to select the most suitable combination of sensors for identification of drugs of abuse in presence of cutting agents. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000714415500006 |
Publication Date |
2021-10-13 |
| Series Editor |
|
Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1572-6657; 1873-2569 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.012 |
Times cited |
|
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 3.012 |
| Call Number |
UA @ admin @ c:irua:184018 |
Serial |
8745 |
| Permanent link to this record |
| |
|
| |
| Author |
Anaf, W.; Trashin, S.; Schalm, O.; van Dorp, D.; Janssens, K.; De Wael, K. |
| Title |
Electrochemical photodegradation study of semiconductor pigments : influence of environmental parameters |
Type |
A1 Journal article |
| Year |
2014 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
86 |
Issue |
19 |
Pages |
9742-9748 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Antwerp Cultural Heritage Sciences (ARCHES) |
| Abstract |
Chemical transformations in paintings often induce discolorations, disturbing the appearance of the image. For an appropriate conservation of such valuable and irreplaceable heritage objects, it is important to have a good know-how on the degradation processes of the (historical) materials: which pigments have been discolored, what are the responsible processes, and which (environmental) conditions have the highest impact on the pigment degradation and should be mitigated. Pigment degradation is already widely studied, either by analyzing historical samples or by accelerated weathering experiments on dummies. However, in historic samples several processes may have taken place, increasing the complexity of the current state, while aging experiments are time-consuming due to the often extended aging period. An alternative method is proposed for a fast monitoring of degradation processes of semiconductor pigments, using an electrochemical setup mimicking the real environment and allowing the identification of harmful environmental parameters for each pigment. Examples are given for the pigments cadmium yellow (CdS) and vermilion (α-HgS). |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
|
| Language |
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Wos |
000343017100058 |
Publication Date |
2014-08-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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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 |
6.32 |
Times cited |
18 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 6.32; 2014 IF: 5.636 |
| Call Number |
UA @ admin @ c:irua:118834 |
Serial |
5593 |
| Permanent link to this record |
| |
|
| |
| Author |
Jaroszewicz, J.; de Nolf, W.; Janssens, K.; Michalski, A.; Falkenberg, G. |
| Title |
Advantages of combined mu-XRF and mu-XRD for phase characterization of Ti-B-C ceramics compared with conventional X-ray diffraction |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Analytical and bioanalytical chemistry |
Abbreviated Journal |
Anal Bioanal Chem |
| Volume |
391 |
Issue |
4 |
Pages |
1129-1133 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000256088700005 |
Publication Date |
2008-05-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1618-2642 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.431 |
Times cited |
7 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.431; 2008 IF: 3.328 |
| Call Number |
UA @ admin @ c:irua:69317 |
Serial |
5459 |
| Permanent link to this record |
| |
|
| |
| Author |
Pilehvar, S.; Mehta, J.; Dardenne, F.; Robbens, J.; Blust, R.; De Wael, K. |
| Title |
Aptasensing of chloramphenicol in the presence of its analogues : reaching the maximum residue limit |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
84 |
Issue |
15 |
Pages |
6753-6758 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
A novel label-free folding induced aptamer-based electrochemical biosensor for the detection of chloramphenicol (CAP) in the presence of its analogues has been developed. CAP is a broad-spectrum antibiotic which has lost its favor due to its serious adverse toxic effects on human health. Aptamers are artificial nucleic acid ligands (ssDNA or RNA) able to specifically recognize a target such as CAP. In this article, the aptamers are fixed onto a gold electrode surface by a self-assembly approach. In the presence of CAP, the unfolded ssDNA on the electrode surface changes to a hairpin structure bringing the target molecules close to the surface and trigger electron transfer. Detection limits were determined to be 1.6×10-9 mol L-1. In addition, thiamphenicol (TAP) and florfenicol (FF), antibiotics with a similar structure to CAP, did not influence the performance of the aptasensor, suggesting a good selectivity of the CAP-aptasensor. Simplicity and lower detection limit (because of the home-selected aptamers) make that the electrochemical aptasensor is suitable for practical use in the detection of CAP in milk samples. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000307159200069 |
Publication Date |
2012-06-20 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.32 |
Times cited |
68 |
Open Access |
|
| Notes |
; ; |
Approved |
Most recent IF: 6.32; 2012 IF: 5.695 |
| Call Number |
UA @ admin @ c:irua:98816 |
Serial |
5477 |
| 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. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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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 |
UA @ admin @ c:irua:76415 |
Serial |
5501 |
| Permanent link to this record |
| |
|
| |
| Author |
Cagno, S.; Brede, D.A.; Nuyts, G.; Vanmeert, F.; Pacureanu, A.; Tucoulou, R.; Cloetens, P.; Falkenberg, G.; Janssens, K.; Salbu, B.; Lind, O.C. |
| Title |
Combined computed nanotomography and nanoscopic x-ray fluorescence imaging of cobalt nanoparticles in caenorhabditis elegans |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
89 |
Issue |
21 |
Pages |
11435-11442 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Synchrotron radiation phase-contrast computed nanotomography (nano-CT) and two-and three-dimensional (2D and 3D) nanoscopic X-ray fluorescence (nano-XRF) were used to investigate the internal distribution of engineered-cobalt nanoparticles (Co NPs) in exposed individuals of the nematode Caenorhabditis elegans. Whole-nematodes and selected tissues and organs were 3D-rendered: anatomical 3D renderings with 50 nm voxel size enabled the visualization of spherical nanoparticle aggregates. with size tip to 200 nm within intact C. elegans. A 20 X 37 nm(2) high-brilliance beam was employed to obtain XRF elemental distribution maps of entire nematodes or anatomical details such as embryos, which could be compared with the CT data, These maps showed Co NPs to be predominantly present within the intestine and the epithelium, and they were not colocalized with Zn granules found in the lysosonie-containing vesicles or Fe agglomerates in the intestine. Iterated XRF scanning of a specimen at 0 degrees and 90 degrees angles suggested that NP aggregates were translocated into tissues outside of the intestinal lumen. Virtual-slicing by means of 2D XRF tomography, combined with holotomography, indicated presumable presence of individual NP aggregates inside the uterus and within embryos. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000414887000041 |
Publication Date |
2017-10-10 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.32 |
Times cited |
13 |
Open Access |
|
| Notes |
; This study has been funded by the Norwegian Research Council through its Centre of Excellence (CoE) funding scheme (Project 223268/F50). We gratefully acknowledge ESRF and DESY for granting beamtime and Karl Andreas Jensen for performing ICPMS analysis. We thank Erica Maremonti for supplying the phase-contrast image used in Figure ^1A. ; |
Approved |
Most recent IF: 6.32 |
| Call Number |
UA @ admin @ c:irua:147383 |
Serial |
5520 |
| Permanent link to this record |
| |
|
| |
| Author |
van der Snickt, G.; Janssens, K.; Dik, J.; de Nolf, W.; Vanmeert, F.; Jaroszewicz, J.; Cotte, M.; Falkenberg, G.; Van der Loeff, L. |
| Title |
Combined use of synchrotron radiation based micro-X-ray fluorescence, micro-X-ray diffraction, micro-X-ray absorption near-edge, and micro-fourier transform infrared spectroscopies for revealing an alternative degradation pathway of the pigment cadmium yellow in a painting by Van Gogh |
Type |
A1 Journal article |
| Year |
2012 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
| Volume |
84 |
Issue |
23 |
Pages |
10221-10228 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Over the past years a number of studies have described the instability of the pigment cadmium yellow (CdS). In a previous paper we have shown how cadmium sulfide on paintings by James Ensor oxidizes to CdSO4 center dot H2O. The degradation process gives rise to the fading of the bright yellow color and the formation of disfiguring white crystals that are present on the paint surface in approximately 50 mu m sized globular agglomerations. Here, we study cadmium yellow in the painting “Flowers in a blue vase” by Vincent van Gogh. This painting differs from the Ensor case in the fact that (a) a varnish was superimposed onto the degraded paint surface and (b) the CdS paint area is entirely covered with an opaque crust. The latter obscures the yellow color completely and thus presents a seemingly more advanced state of degradation. Analysis of a cross-sectioned and a crushed sample by combining scanning microscopic X-ray diffraction (mu-XRD), microscopic X-ray absorption near-edge spectroscopy (mu-XANES), microscopic X-ray fluorescence (mu-XRF) based chemical state mapping and scanning microscopic Fourier transform infrared (mu-FT-IR) spectrometry allowed unravelling the complex alteration pathway. Although no crystalline CdSO4 compounds were identified on the Van Gogh paint samples, we conclude that the observed degradation was initially caused by oxidation of the original CdS pigment, similar as for the previous Ensor case. However, due to the presence of an overlying varnish containing lead-based driers and oxalate ions, secondary reactions took place. In particular, it appears that upon the photoinduced oxidation of its sulfidic counterion, the Cd2+ ions reprecipitated at the paint/varnish interface after having formed a complex with oxalate ions that themselves are considered to be degradation products of the resin and/or oil in the varnish. The SO42- anions, for their part, found a suitable reaction partner in Pb2+ ions stemming from a dissolved lead-based siccative that was added to the varnish to promote its drying. The resulting opaque anglesite compound in the varnish, in combination with the underlying CdC2O4 layer at the paint/varnish interface, account for the orange-gray crust that is disfiguring the painting on a macroscopic level. In this way, the results presented in this paper demonstrate how, through a judicious combined use of several microanalytical methods with speciation capabilities, many new insights can be obtained from two minute, but highly complex and heterogeneous paint samples. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
|
| Language |
|
Wos |
000311815300013 |
Publication Date |
2012-08-30 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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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 |
6.32 |
Times cited |
59 |
Open Access |
|
| Notes |
; This research was supported by BELSPO via the Interuniversity Attraction Poles Programme (IUAP VI/16) and the S2-ART project (SD/RI/04A) and funded by Grants from the ESRF (EC-442) and PETRA-III (I-20120312 EC). 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 Kroller-Muller Museum and painting conservators Margje Leeuwestein and Esther Van Duijn are acknowledged for this pleasant cooperation and the authorization for the publication of the images in this article. ; |
Approved |
Most recent IF: 6.32; 2012 IF: 5.695 |
| Call Number |
UA @ admin @ c:irua:105971 |
Serial |
5526 |
| Permanent link to this record |
| |
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| |
| Author |
Cagno, S.; Janssens, K.; Mendera, M. |
| Title |
Compositional analysis of Tuscan glass samples: in search of raw materials fingerprints |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Analytical and bioanalytical chemistry |
Abbreviated Journal |
Anal Bioanal Chem |
| Volume |
391 |
Issue |
4 |
Pages |
1389-1395 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
|
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
|
| Language |
|
Wos |
000256088700035 |
Publication Date |
2008-02-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1618-2642 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.431 |
Times cited |
26 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.431; 2008 IF: 3.328 |
| Call Number |
UA @ admin @ c:irua:69320 |
Serial |
5545 |
| Permanent link to this record |
| |
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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. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000346683900048 |
Publication Date |
2014-11-13 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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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 |
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 |
| Permanent link to this record |
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| |
| 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 |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000313668400032 |
Publication Date |
2012-10-10 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| 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 |
| |
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| |
| 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. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000344510200043 |
Publication Date |
2014-10-10 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0003-2700; 5206-882x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
6.32 |
Times cited |
25 |
Open Access |
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| 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 |
