Records |
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 ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
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 |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
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 |
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 ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
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 |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000648505900008 |
Publication Date |
2021-05-04 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
|
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 |
|
|
|
Author |
Vanmeert, F.; de Nolf, W.; Dik, J.; Janssens, K. |
Title |
Macroscopic X-ray powder diffraction scanning : possibilities for quantitative and depth-selective parchment analysis |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
90 |
Issue |
11 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
6445-6452 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
At or below the surface of painted works of art, valuable information is present that provides insights into an objects past, such as the artists technique and the creative process that was followed or its conservation history but also on its current state of preservation. Various noninvasive techniques have been developed over the past 2 decades that can probe this information either locally (via point analysis) or on a macroscopic scale (e.g., full-field imaging and raster scanning). Recently macroscopic X-ray powder diffraction (MA-XRPD) mapping using laboratory X-ray sources was developed. This method can visualize highly specific chemical distributions at the macroscale (dm(2)). In this work we demonstrate the synergy between the quantitative aspects of powder diffraction and the noninvasive scanning capability of MA-XRPD highlighting the potential of the method to reveal new types of information. Quantitative data derived from a 15th/16th century illuminated sheet of parchment revealed three lead white pigments with different hydrocerussite-cerussite compositions in specific pictorial elements, while quantification analysis of impurities in the blue azurite pigment revealed two distinct azurite types: one rich in barite and one in quartz. Furthermore, on the same artifact, the depth-selective possibilities of the method that stem from an exploitation of the shift of the measured diffraction peaks with respect to reference data are highlighted. The influence of different experimental parameters on the depth-selective analysis results is briefly discussed. Promising stratigraphic information could be obtained, even though the analysis is hampered by not completely understood variations in the unit cell dimensions of the crystalline pigment phases. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000434893200020 |
Publication Date |
2018-04-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
6 |
Open Access |
|
Notes |
; The authors thank Incoatec GmbH for giving us the opportunity to test the I mu S Cu X-ray source. We acknowledge financial support from BELSPO (Brussels) S2-ART, the NWO (The Hague) Science4Arts “ReVisRembrandt” project, and GOA Project Solarpaint (University of Antwerp Research Council). Photo Copyright Geert Van der Snickt, 2008 for the photograph of the illuminated manuscript in the TOC graphic. ; |
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ admin @ c:irua:151994 |
Serial |
5702 |
Permanent link to this record |
|
|
|
Author |
Vanmeert, F.; de Nolf, W.; De Meyer, S.; Dik, J.; Janssens, K. |
Title |
Macroscopic X-ray powder diffraction scanning, a new method for highly selective chemical imaging of works of art : instrument optimization |
Type |
A1 Journal article |
Year |
2018 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
90 |
Issue |
11 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
6436-6444 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
In the past decade macroscopic X-ray fluorescence imaging (MA-XRF) has become established as a method for the noninvasive investigation of flat painted surfaces, yielding large scale elemental maps. MA-XRF is limited by a lack of specificity, only allowing for indirect pigment identification based on the simultaneous presence of chemical elements. The high specificity of X-ray powder diffraction (XRPD) mapping is already being exploited at synchrotron facilities for investigations at the (sub)microscopic scale, but the technique has not yet been employed using lab sources. In this paper we present the development of a novel MA-XRPD/XRF instrument based on a laboratory X-ray source. Several combinations of X-ray sources and area detectors are evaluated in terms of their spatial and angular resolution and their sensitivity. The highly specific imaging capability of the combined MA-XRPD/XRF instrument is demonstrated on a 15th/16th century illuminated manuscript directly revealing the distribution of a large number of inorganic pigments, including the uncommon yellow pigment massicot (o-PbO). The case study illustrates the wealth of new mapping information that can be obtained in a noninvasive manner using the laboratory MA-XRPD/XRF instrument. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000434893200019 |
Publication Date |
2018-04-06 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
11 |
Open Access |
|
Notes |
; The authors thank the persons involved at Incoatec GmbH, imXPAD SAS and Dectris Ltd. for loaning us some of their products over the past years. We acknowledge financial support from BELSPO (Brussels) S2-ART, the NWO (The Hague) Science4Arts “ReVisRembrandt” Project and GOA Project Solarpaint (University of Antwerp Research Council). Photo Copyright Geert Van der Snickt, 2008 for the photograph of the illuminated manuscript in the TOC graphic. ; |
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ admin @ c:irua:151993 |
Serial |
5701 |
Permanent link to this record |
|
|
|
Author |
Dik, J.; Janssens, K.; van der Snickt, G.; van der Loeff, L.; Rickers, K.; Cotte, M. |
Title |
Visualization of a lost painting by Vincent van Gogh using synchrotron radiation based X-ray fluorescence elemental mapping |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
80 |
Issue |
16 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
6436-6442 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Vincent van Gogh (1853−1890), one of the founding fathers of modern painting, is best known for his vivid colors, his vibrant painting style, and his short but highly productive career. His productivity is even higher than generally realized, as many of his known paintings cover a previous composition. This is thought to be the case in one-third of his early period paintings. Van Gogh would often reuse the canvas of an abandoned painting and paint a new or modified composition on top. These hidden paintings offer a unique and intimate insight into the genesis of his works. Yet, current museum-based imaging tools are unable to properly visualize many of these hidden images. We present the first-time use of synchrotron radiation based X-ray fluorescence mapping, applied to visualize a womans head hidden under the work Patch of Grass by Van Gogh. We recorded decimeter-scale, X-ray fluorescence intensity maps, reflecting the distribution of specific elements in the paint layers. In doing so we succeeded in visualizing the hidden face with unprecedented detail. In particular, the distribution of Hg and Sb in the red and light tones, respectively, enabled an approximate color reconstruction of the flesh tones. This reconstruction proved to be the missing link for the comparison of the hidden face with Van Goghs known paintings. Our approach literally opens up new vistas in the nondestructive study of hidden paint layers, which applies to the oeuvre of Van Gogh in particular and to old master paintings in general. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000258448100039 |
Publication Date |
2008-07-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
178 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 2008 IF: 5.712 |
Call Number |
UA @ admin @ c:irua:74466 |
Serial |
5906 |
Permanent link to this record |
|
|
|
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 ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
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 |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000522701700005 |
Publication Date |
2020-03-31 |
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 |
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 |
|
|
|
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 ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
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 |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000805334400013 |
Publication Date |
2022-03-28 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record |
Impact Factor |
7.4 |
Times cited |
|
Open Access |
OpenAccess |
Notes |
|
Approved |
Most recent IF: 7.4 |
Call Number |
UA @ admin @ c:irua:189093 |
Serial |
7143 |
Permanent link to this record |
|
|
|
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 ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
5290-5297 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre |
Abstract |
The present work investigates the electrochemical determination of cocaine in the presence of levamisole, one of the most common adulterants found in cocaine street samples. Levamisole misleads cocaine color tests, giving a blue color (positive test) even in the absence of cocaine. Moreover, the electrochemical detection of cocaine is also affected by the presence of levamisole, with a suppression of the oxidation signal of cocaine. When levamisole is present in the sample in ratios higher than 1:1, the cocaine signal is no longer detected, thus leading to false negative results. Mass spectrometry and nuclear magnetic resonance were used to investigate if the signal suppression is due to the formation of a complex between cocaine and levamisole in bulk solution. Strategies to eliminate this suppressing effect are further suggested in this manuscript. In a first approach, the increase of the pH of the sample solution from pH 7 to pH 12 allowed the voltammetric determination of cocaine in the presence of levamisole in a concentration range from 10 to 5000 μM at nonmodified graphite disposable electrodes with a detection limit of 5 μM. In a second approach, the graphite electrode was cathodically pretreated, resulting in the presence of oxidation peaks of both cocaine and levamisole, with a detection limit for cocaine of 3 μM over the linear range of concentrations from 10 to 2500 μM. Both these strategies have been successfully applied for the simultaneous detection of cocaine and levamisole in three street samples on unmodified graphite disposable electrodes. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000430512200049 |
Publication Date |
2018-02-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
8 |
Open Access |
|
Notes |
; This project has received funding from the European Union's Horizon 2020 Research and Innovation Programme under the Marie Sklodowska-Curie Grant Agreement No. 753223 Narcoreader. This work was also supported by BR/314/PI/ APTADRU Project and IOF-SBO (UAntwerp). Alexander van Nuijs acknowledges the Research Foundation-Flanders (FWO) for his postdoctoral fellowship. ; |
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ admin @ c:irua:149528 |
Serial |
5693 |
Permanent link to this record |
|
|
|
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 ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
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 |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000786254500002 |
Publication Date |
2022-03-22 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
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 |
|
|
|
Author |
Kempenaers, L.; Janssens, K.; Vincze, L.; Vekemans, B.; Somogyi, A.; Drakopoulos, M.; Simionovici, A.S.; Adams, F. |
Title |
A Monte Carlo model for studying the microheterogeneity of trace elements in reference materials by means of synchrotron microscopic X-ray fluorescence |
Type |
A1 Journal article |
Year |
2002 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
74 |
Issue |
19 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
5017-5026 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000178418100031 |
Publication Date |
2002-09-30 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
21 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 2002 IF: 5.094 |
Call Number |
UA @ admin @ c:irua:39871 |
Serial |
5734 |
Permanent link to this record |
|
|
|
Author |
De Wael, K.; Daems, D.; Van Camp, G.; Nagels, L.J. |
Title |
The use of potentiometric sensors to study (bio)molecular interactions |
Type |
A1 Journal article |
Year |
2012 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
84 |
Issue |
11 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
4921-4927 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Potentiometric sensors were used to study molecular interactions in liquid environments, with sensorgram methodology. This is demonstrated with a lipophilic rubber-, and with a collagen based hydrogel sensor coating. The investigated molecules were promazine and tartaric acid respectively. The sensors were placed in a hydrodynamic wall jet system for the recording of sensorgrams. mV sensor responses were first converted to a signal, expressing the concentration of adsorbed organic ions. Using a linearization method, a pseudo first order kinetic model of adsorption was shown to fit the experimental results perfectly. Kass, kon and koff values were calculated.. The technique can be used over 4 decades of concentration, and it is very sensitive to low MW compounds as well as to multiply charged large biomolecules. This study is the first to demonstrate the application of potentiometric sensors as an alternative and complement to SPR methods. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000304783100041 |
Publication Date |
2012-04-28 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
10 |
Open Access |
|
Notes |
; Financial support for this work was provided by the University of Antwerp by granting D.D. a BOF interdisciplinary research project. We thank J. Everaert for his help in interpreting the results. K.D.W. and D.D. contributed equally to this work. ; |
Approved |
Most recent IF: 6.32; 2012 IF: 5.695 |
Call Number |
UA @ admin @ c:irua:97520 |
Serial |
5898 |
Permanent link to this record |
|
|
|
Author |
Dillen, A.; Vandezande, W.; Daems, D.; Lammertyn, J. |
Title |
Unraveling the effect of the aptamer complementary element on the performance of duplexed aptamers : a thermodynamic study |
Type |
A1 Journal article |
Year |
2021 |
Publication |
Analytical And Bioanalytical Chemistry |
Abbreviated Journal |
Anal Bioanal Chem |
Volume |
413 |
Issue |
19 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
4739-4750 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Duplexed aptamers (DAs) are widespread aptasensor formats that simultaneously recognize and signal the concentration of target molecules. They are composed of an aptamer and aptamer complementary element (ACE) which consists of a short oligonucleotide that partially inhibits the aptamer sequence. Although the design principles to engineer DAs are straightforward, the tailored development of DAs for a particular target is currently based on trial and error due to limited knowledge of how the ACE sequence affects the final performance of DA biosensors. Therefore, we have established a thermodynamic model describing the influence of the ACE on the performance of DAs applied in equilibrium assays and demonstrated that this relationship can be described by the binding strength between the aptamer and ACE. To validate our theoretical findings, the model was applied to the 29-mer anti-thrombin aptamer as a case study, and an experimental relation between the aptamer-ACE binding strength and performance of DAs was established. The obtained results indicated that our proposed model could accurately describe the effect of the ACE sequence on the performance of the established DAs for thrombin detection, applied for equilibrium assays. Furthermore, to characterize the binding strength between the aptamer and ACEs evaluated in this work, a set of fitting equations was derived which enables thermodynamic characterization of DNA-based interactions through thermal denaturation experiments, thereby overcoming the limitations of current predictive software and chemical denaturation experiments. Altogether, this work encourages the development, characterization, and use of DAs in the field of biosensing. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000659366300001 |
Publication Date |
2021-06-10 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
1618-2642; 1618-2650 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
3.431 |
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
|
Approved |
Most recent IF: 3.431 |
Call Number |
UA @ admin @ c:irua:179163 |
Serial |
8713 |
Permanent link to this record |
|
|
|
Author |
Bings, N.H.; Bogaerts, A.; Broekaert, J.A.C. |
Title |
Atomic spectroscopy: a review |
Type |
A1 Journal article |
Year |
2010 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
82 |
Issue |
12 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
4653-4681 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000278616100001 |
Publication Date |
2010-05-13 |
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 |
65 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 2010 IF: 5.874 |
Call Number |
UA @ lucian @ c:irua:82675 |
Serial |
195 |
Permanent link to this record |
|
|
|
Author |
Bings, N.H.; Bogaerts, A.; Broekaert, J.A.C. |
Title |
Atomic spectroscopy |
Type |
A1 Journal article |
Year |
2008 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
80 |
Issue |
12 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
4317-4347 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000256763400006 |
Publication Date |
2008-05-08 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700;1520-6882; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
53 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 2008 IF: 5.712 |
Call Number |
UA @ lucian @ c:irua:69437 |
Serial |
191 |
Permanent link to this record |
|
|
|
Author |
Lindner, H.; Autrique, D.; Garcia, C.C.; Niemax, K.; Bogaerts, A. |
Title |
Optimized transport setup for high repetition rate pulse-separated analysis in laser ablation-inductively coupled plasma mass spectrometry |
Type |
A1 Journal article |
Year |
2009 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
81 |
Issue |
11 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
4241-4248 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
An optimized laser ablation setup, proposed for high repetition rate inductively coupled plasma mass spectrometry (ICPMS) analyses such as 2D imaging or depth profiling, is presented. For such applications, the particle washout time needs to be as short as possible to allow high laser pulse frequencies for reduced analysis time. Therefore, it is desirable to have an ablation setup that operates as a laminar flow reactor (LFR). A top-down strategy was applied that resulted in the present design. In the first step, a previously applied ablation setup was analyzed on the basis of computational fluid dynamics (CFD) results presented by D. Autrique et al. (Spectrochim. Acta, B 2008, 63, 257−270). By means of CFD simulations, the design was modified in such a way that it operated in the LFR regime. Experimental results demonstrate that the current design can indeed be regarded as an LFR. Furthermore, the operation under LFR conditions allowed some insight into the initial radial concentration distribution if the experimental ICPMS signal and analytical expressions are taken into account. Recommendations for a modified setup for more resilient spatial distributions are given. With the present setup, a washout time of 140 ms has been achieved for a 3% signal area criterion. Therefore, 7 Hz repetition rates can be applied with the present setup. Using elementary formulas of the analytical model, an upper bound for the washout times for similar setups can be predicted. The authors believe that the presented setup geometry comes close to the achievable limit for reliable short washout times. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000266601800014 |
Publication Date |
2009-04-29 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700;1520-6882; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
18 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 2009 IF: 5.214 |
Call Number |
UA @ lucian @ c:irua:76935 |
Serial |
2492 |
Permanent link to this record |
|
|
|
Author |
Newsome, G.A.; Kavich, G.; Alvarez-Martin, A. |
Title |
Interface for reproducible, multishot direct analysis of solid-phase microextraction samples |
Type |
A1 Journal article |
Year |
2020 |
Publication |
Analytical Chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
92 |
Issue |
6 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
4182-4186 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
An enclosed interface that joins a direct analysis in real time (DART) probe, solid-phase microextraction (SPME) fiber, and the inlet of a high-resolution mass spectrometer is described. Unlike other systems to couple SPME sampling to ambient mass spectrometry, the interface is able to perform discrete analyses on different areas of a single SPME fiber device for up to three technical replicate measurements of one sampling event. Inlet flow speed and desorption temperature are optimized, and reproducibility is demonstrated between replicate analyses on the same derivatized SPME fiber and with sequential fiber sampling events, yielding analyte measurement center of variance (CV) from 3 to 6%. Conditioning is also performed with the enclosed DART. The interface is a straightforward addition to commercially available technologies, and machine diagrams for custom components operated with SPME/DART/MS equipment are included. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000526563900004 |
Publication Date |
2020-02-07 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
7.4 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 7.4; 2020 IF: 6.32 |
Call Number |
UA @ admin @ c:irua:181926 |
Serial |
8113 |
Permanent link to this record |
|
|
|
Author |
Bings, N.H.; Bogaerts, A.; Broekaert, J.A.C. |
Title |
Atomic spectroscopy |
Type |
A1 Journal article |
Year |
2006 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
78 |
Issue |
12 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
3917-3945 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000238252600007 |
Publication Date |
2006-06-10 |
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 |
112 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 2006 IF: 5.646 |
Call Number |
UA @ lucian @ c:irua:60058 |
Serial |
192 |
Permanent link to this record |
|
|
|
Author |
Verlinden, G.; Janssens, G.; Gijbels, R.; van Espen, P.; Geuens, I. |
Title |
Three-dimensional chemical characterization of complex silver halide microcrystals by scanning ion microprobe mass analysis |
Type |
A1 Journal article |
Year |
1997 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
69 |
Issue |
|
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
3773-3779 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Chemometrics (Mitac 3) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
A1997XV71200019 |
Publication Date |
2002-07-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700;1520-6882; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
6 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 1997 IF: 4.743 |
Call Number |
UA @ lucian @ c:irua:16959 |
Serial |
3647 |
Permanent link to this record |
|
|
|
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 ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
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 |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000518234700023 |
Publication Date |
2020-01-27 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
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 |
|
|
|
Author |
Terzano, R.; Alfeld, M.; Janssens, K.; Vekemans, B.; Schoonjans, T.; Vincze, L.; Tomasi, N.; Pinton, R.; Cesco, S. |
Title |
Spatially resolved (semi)quantitative determination of iron (Fe) in plants by means of synchrotron micro X-ray fluorescence |
Type |
A1 Journal article |
Year |
2013 |
Publication |
Analytical and bioanalytical chemistry |
Abbreviated Journal |
Anal Bioanal Chem |
Volume |
405 |
Issue |
10 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
3341-3350 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Iron (Fe) is an essential element for plant growth and development; hence determining Fe distribution and concentration inside plant organs at the microscopic level is of great relevance to better understand its metabolism and bioavailability through the food chain. Among the available microanalytical techniques, synchrotron mu-XRF methods can provide a powerful and versatile array of analytical tools to study Fe distribution within plant samples. In the last years, the implementation of new algorithms and detection technologies has opened the way to more accurate (semi)quantitative analyses of complex matrices like plant materials. In this paper, for the first time the distribution of Fe within tomato roots has been imaged and quantified by means of confocal mu-XRF and exploiting a recently developed fundamental parameter-based algorithm. With this approach, Fe concentrations ranging from few hundreds of ppb to several hundreds of ppm can be determined at the microscopic level without cutting sections. Furthermore, Fe (semi)quantitative distribution maps were obtained for the first time by using two opposing detectors to collect simultaneously the XRF radiation emerging from both sides of an intact cucumber leaf. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000316338700033 |
Publication Date |
2013-02-07 |
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 |
27 |
Open Access |
|
Notes |
; Research was supported by grants from Italian MIUR (FIRB-Programma “Futuro in Ricerca”) and Free University of Bolzano (TN5046 and TN5056). Synchrotron experiments at HASY-LAB were financially supported by the European Community Research Infrastructure Action under the FP6 “Structuring the European Research Area” Program I (Integrating Activity on Synchrotron and Free Electron Laser Science; project: contract RII3-CT-2004-506008). Matthias Alfeld receives a Ph.D. fellowship of the Research Foundation-Flanders (FWO). We thank Karen Rickers-Appel for her scientific and technical support in obtaining the experimental data at Beamline L (HASYLAB, DESY, Hamburg, Germany). ; |
Approved |
Most recent IF: 3.431; 2013 IF: 3.578 |
Call Number |
UA @ admin @ c:irua:108261 |
Serial |
5838 |
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 ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
3326-3334 |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT); AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Chrome yellow refers to a group of synthetic inorganic pigments that became popular as an artists material from the second quarter of the 19th century. The color of the pigment, in which the chromate ion acts as a chromophore, is related to its chemical composition (PbCr1-xSxO4, with 0≤x≤0.8) and crystalline structure (monoclinic/orthorhombic). Their shades range from the yellow-orange to the paler yellow tones with increasing sulfate amount. These pigments show remarkable signs of degradation after limited time periods. Pure PbCrO4 (crocoite in its natural form) has a deep yellow color and is relatively stable, while the co-precipitate with lead sulfate (PbCr1-xSxO4) has a paler shade and seems to degrade faster. This degradation is assumed to be related to the reduction of Cr(VI) to Cr(III). We show that on increasing the sulfur(S)-content in chrome yellow, the band gap increases. Typically, when increasing the band gap, one might assume that a decrease in photo activity is the result. However, the photo activity relative to the Cr content, and thus Cr reduction, of sulfur-rich PbCr1-xSxO4 is found to be much higher compared to the sulfur-poor or non-doped lead chromates. This discrepancy can be explained by the evolution of the crystal and electronic structure as function of the sulfur content: first-principles density functional theory calculations show that both the absorption coefficient and reflection coefficients of the lead chromates change as a result of the sulfate doping in such a way that the generation of electron-hole pairs under illumination relative to the total Cr content increases. These changes in the material properties explain why paler shade yellow colors of this pigment are more prone to discoloration. The electronic structure calculations also demonstrate that lead chromate and its co-precipitates are p-type semiconductors, which explains the observed reduction reaction. As understanding this phenomenon is valuable in the field of cultural heritage, this study is the first joint action of photo-electrochemical measurements and first-principles calculations to approve the higher tendency of sulfur-rich lead chromates to darken. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000397478300015 |
Publication Date |
2017-02-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
7 |
Open Access |
OpenAccess |
Notes |
; The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government, department EWI. The BOF-GOA action SOLARPAINT of the University of Antwerp Research Council is acknowledged for financial support. W.A. acknowledges support from BELSPO project S2-ART. Dr. L. Monico and Dr. C. Miliani (ISTM, Perugia) are gratefully acknowledged for helpful discussions and for providing some of the initial batches of the materials studied. ; |
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ lucian @ c:irua:140886 |
Serial |
4451 |
Permanent link to this record |
|
|
|
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 ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
3315-3323 |
Keywords |
A1 Journal article; Engineering sciences. Technology; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Herein, thin-layer potentiometry combined with ion-exchange membranes as barriers for charged interferences is demonstrated for the analytical detection of creatinine (CRE) in undiluted human urine. Briefly, CRE diffuses through an anion-exchange membrane (AEM) from a sample contained in one fluidic compartment to a second reservoir, containing the enzyme CRE deiminase. There, CRE reacts with the enzyme, and the formation of ammonium is dynamically monitored by potentiometric ammonium-selective electrodes. This analytical concept is integrated into a lab-on-a-chip microfluidic cell that allows for a high sample throughput and the operation under stop-flow mode, which allows CRE to passively diffuse across the AEM. Conveniently, positively charged species (i.e., potassium, sodium, and ammonium, among others) are repelled by the AEM and never reach the ammonium-selective electrodes; thus, possible interference in the response can be avoided. As a result, the dynamic potential response of the electrodes is entirely ascribed to the stoichiometric formation of ammonium. The new CRE biosensor exhibits a Nernstian slope, within a linear range of response from 1 to 50 mM CRE concentration. As expected, the response time (15–60 min) primarily depends on the CRE diffusion across the AEM. CRE analysis in urine samples displayed excellent results, without requiring sample pretreatment (before the introduction of the sample in the microfluidic chip) and with high compatibility with development into a potential point-of-care clinical tool. In an attempt to decrease the analysis time, the presented analytical methodology for CRE detection is translated into an all-solid-state platform, in which the enzyme is immobilized on the surface of the ammonium-selective electrode and with the AEM on top. While more work is necessary in this direction, the CRE sensor appears to be promising for CRE analysis in both urine and blood. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
|
Publication Date |
2020-01-23 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record |
Impact Factor |
7.4 |
Times cited |
|
Open Access |
|
Notes |
|
Approved |
Most recent IF: 7.4; 2020 IF: 6.32 |
Call Number |
UA @ admin @ c:irua:184380 |
Serial |
8667 |
Permanent link to this record |
|
|
|
Author |
Bings, N.H.; Bogaerts, A.; Broekaert, J.A.C. |
Title |
Atomic spectroscopy |
Type |
A1 Journal article |
Year |
2004 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
76 |
Issue |
12 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
3313-3336 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000222011100006 |
Publication Date |
2004-06-14 |
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 |
32 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 2004 IF: 5.450 |
Call Number |
UA @ lucian @ c:irua:46258 |
Serial |
193 |
Permanent link to this record |
|
|
|
Author |
Bings, N.H.; Bogaerts, A.; Broekaert, J.A.C. |
Title |
Atomic spectroscopy |
Type |
A1 Journal article |
Year |
2002 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
74 |
Issue |
12 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
2691-2712 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000176253700006 |
Publication Date |
2002-07-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700;1520-6882; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
18 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 2002 IF: 5.094 |
Call Number |
UA @ lucian @ c:irua:40192 |
Serial |
194 |
Permanent link to this record |
|
|
|
Author |
Bogaerts, A.; Gijbels, R. |
Title |
Two-dimensional model of a direct current glow discharge : description of the argon metastable atoms, sputtered atoms and ions |
Type |
A1 Journal article |
Year |
1996 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
68 |
Issue |
15 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
2676-2685 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
A two-dimensional model is presented that describes the behavior of argon metastable atoms, copper atoms, and copper ions in an argon direct. current glow discharge, in the standard cell of the VG9000 glow discharge mass spectrometer for analyzing flat samples. The model is combined with a previously developed model for the electrons, argon ions, and atoms in the same cell to obtain an overall picture of the glow discharge, The results of the present model comprise the number densities of the described plasma species, the relative contributions of different production and loss processes for the argon metastable atoms, the thermalization profile of the sputtered copper atoms, the relative importance of the different ionization mechanisms for the copper atoms, the ionization degree of copper, the copper ion-to-argon ion density ratio, and the relative roles of copper ions, argon ions, and atoms in the sputtering process. All these quantities are calculated for a range of voltages and pressures, Moreover, since the sticking coefficient of copper atoms on solid surfaces is not well-known in the literature, the influence of this parameter on the results is briefly discussed. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
A1996VA00300042 |
Publication Date |
2002-07-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700;1520-6882; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
5.636 |
Times cited |
57 |
Open Access |
|
Notes |
|
Approved |
no |
Call Number |
UA @ lucian @ c:irua:16242 |
Serial |
3775 |
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 ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
2600-2610 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
On several paintings of James Ensor (1860−1949), a gradual fading of originally bright yellow areas, painted with the pigment cadmium yellow (CdS), is observed. Additionally, in some areas exposed to light, the formation of small white-colored globules on top of the original paint surface is observed. In this paper the chemical transformation leading to the color change and to the formation of the globules is elucidated. Microscopic X-ray absorption near-edge spectroscopy (ì-XANES) experiments show that sulfur, originally present in sulfidic form (S2−), is oxidized during the transformation to the sulfate form (S6+). Upon formation (at or immediately below the surface), the highly soluble cadmium sulfate is assumed to be transported to the surface in solution and reprecipitates there, forming the whitish globules. The presence of cadmium sulfate (CdSO4·2H2O) and ammonium cadmium sulfate [(NH4)2Cd(SO4)2] at the surface is confirmed by microscopic X-ray diffraction measurements, where the latter salt is suspected to result from a secondary reaction of cadmium sulfate with ammonia. Measurements performed on cross sections reveal that the oxidation front has penetrated into the yellow paint down to ca. 1−2 ìm. The morphology and elemental distribution of the paint and degradation product were examined by means of scanning electron microscopy equipped with an energy-dispersive spectrometer (SEM-EDS) and synchrotron radiation based micro-X-ray fluorescence spectrometry (SR ì-XRF). In addition, ultraviolet-induced visible fluorescence photography (UIVFP) revealed itself to be a straightforward technique for documenting the occurrence of this specific kind of degradation on a macroscale by painting conservators. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000264759400025 |
Publication Date |
2009-03-11 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
91 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 2009 IF: 5.214 |
Call Number |
UA @ admin @ c:irua:76415 |
Serial |
5501 |
Permanent link to this record |
|
|
|
Author |
Rouchon, V.; Duranton, M.; Burgaud, C.; Pellizzi, E.; Lavédrine, B.; Janssens, K.; de Nolf, W.; Nuyts, G.; Vanmeert, F.; Hellemans, K. |
Title |
Room-temperature study of iron gall ink impregnated paper degradation under various oxygen and humidity conditions : time-dependent monitoring by viscosity and X-ray absorption near-edge spectrometry measurements |
Type |
A1 Journal article |
Year |
2011 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
83 |
Issue |
7 |
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
2589-2597 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
Abstract |
Many western manuscripts were written using iron gall inks. These inks can damage the paper via two major mechanisms: (a) acid hydrolysis, enhanced by humidity, and (b) oxidative depolymerization provoked by the presence of oxygen and free iron(II) ions. The degradation of unsized Whatman paper impregnated with different combinations of iron sulfate, gallic acid, and gum arabic was studied at room temperature in order to assess the relative importance of each mechanism. The samples were stored in various environments including a dry and/or an oxygen-free atmosphere. The cellulose depolymerization was monitored by viscometry and related to changes in the oxidation state of iron, determined by X-ray absorption near-edge spectrometry. The results indicate that residual amounts of oxygen (less than 0.1%) promote cellulose depolymerization, whereas the level of relative humidity has no impact. The cellulose depolymerization also appears closely correlated to oxidative mechanisms. Regarding the oxidation of iron, it only occurs in the simultaneous presence of oxygen and moisture, suggesting the occurrence of rustlike oxidative mechanisms. Finally, the presence of gallic acid has a strong influence, which is only partially explained by its capacity to reduce iron(III) to iron(II). |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000288887700028 |
Publication Date |
2011-03-04 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
28 |
Open Access |
|
Notes |
; This research was supported by the French Ministry of Culture within the National Program of Research (“La conservation des manuscrits: etude du vieillissement naturel de papiers impregnes d'encres ferrogalliques”). It was funded by grants from HASYLAB (experiments I-20090280 EC and II-20060245 EC) and SOLEIL (proposals 20060396 and 20080761) and was supported by the Interuniversity Attraction Poles Programme Belgian Science Policy (1UAP V1/16). The text also presents results of GOA “XANES meets ELNES” (Research Fund University of Antwerp, Belgium) and from FWO (Brussels, Belgium) projects nos. G.0689.06, G.0704.08 and G017909N. We are thankful to Dr. Dominique Thaudiere, Dr. Solenn Reguer, Dr. Andrea Somogyi, Dr. Karen Appel, Dr. Manuela Borchert, and Dr. Gerald Falkenberg for their assistance and help during the experiments performed at SOLEIL beamline “DIFFABS” and at HASYLAB Beam line “L” respectively. ; |
Approved |
Most recent IF: 6.32; 2011 IF: 5.856 |
Call Number |
UA @ admin @ c:irua:89593 |
Serial |
5822 |
Permanent link to this record |
|
|
|
Author |
Gregory, C.L.; Nullens, H.A.; Gijbels, R.H.; van Espen, P.J.; Geuens, I.; de Keyzer, R. |
Title |
Automated particle analysis of populations of silver halide microcrystals by electron probe microanalysis under cryogenic conditions |
Type |
A1 Journal article |
Year |
1998 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
70 |
Issue |
|
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
2551-2559 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT); Chemometrics (Mitac 3) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
000074584700047 |
Publication Date |
2002-07-26 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700;1520-6882; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
12 |
Open Access |
|
Notes |
|
Approved |
Most recent IF: 6.32; 1998 IF: 4.580 |
Call Number |
UA @ lucian @ c:irua:21308 |
Serial |
210 |
Permanent link to this record |
|
|
|
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 ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
2394-2402 |
Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Toxicological Centre |
Abstract |
The electrochemical detection of cephalosporins is a promising approach for the monitoring of cephalosporin levels in process waters. However, this class of antibiotics, like penicillins, is composed of chemically active molecules and susceptible to hydrolysis and aminolysis of the four membered β-lactam ring present. In order to develop a smart monitoring strategy for cephalosporins, the influence of degradation (hydrolysis and aminolysis) on the electrochemical fingerprint has to be taken into account. Therefore, an investigation was carried out to understand the changes of the voltammetric fingerprints upon acidic and alkaline degradation. Changes in fingerprints were correlated to the degradation pathways through the combination of square wave voltammetry and liquid chromatography quadrupole time-of-flight analysis. The characteristic electrochemical signals of the β-lactam ring disappeared upon hydrolysis. Additional oxidation signals that appeared after degradation were elucidated and linked to different degradation products, and therefore, enrich the voltammetric fingerprints with information of the state of the cephalosporins. The applicability of the electrochemical monitoring system was explored by the analysis of the intact and degraded industrial process waters containing the key intermediate 7-aminodeacetoxycephalosporanic acid (7-ADCA). Clearly, the intact process samples exhibited the expected core signals of 7-ADCA and could be quantified, while the degraded samples only showed the newly formed degradation products. |
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
|
Editor |
|
Language |
|
Wos |
000618089100063 |
Publication Date |
2021-01-04 |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
Series Volume |
|
Series Issue |
|
Edition |
|
ISSN |
0003-2700; 5206-882x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
Impact Factor |
6.32 |
Times cited |
|
Open Access |
Not_Open_Access |
Notes |
|
Approved |
Most recent IF: 6.32 |
Call Number |
UA @ admin @ c:irua:176206 |
Serial |
7864 |
Permanent link to this record |
|
|
|
Author |
Vertes, A.; Irinyi, G.; Gijbels, R. |
Title |
Hydrodynamic model of matrix-assisted laser desorption mass spectrometry |
Type |
A1 Journal article |
Year |
1993 |
Publication |
Analytical chemistry |
Abbreviated Journal |
Anal Chem |
Volume |
65 |
Issue |
|
Pages ![sorted by First Page field, descending order (down)](img/sort_desc.gif) |
2389-2393 |
Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
Abstract |
|
Address |
|
Corporate Author |
|
Thesis |
|
Publisher |
|
Place of Publication |
Washington, D.C. |
Editor |
|
Language |
|
Wos |
A1993LU63400039 |
Publication Date |
2007-05-30 |
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 |
5.636 |
Times cited |
100 |
Open Access |
|
Notes |
|
Approved |
CHEMISTRY, PHYSICAL 77/144 Q3 # MATHEMATICS, INTERDISCIPLINARY 19/101 Q1 # PHYSICS, ATOMIC, MOLECULAR & CHEMICAL 17/35 Q2 # |
Call Number |
UA @ lucian @ c:irua:6161 |
Serial |
1530 |
Permanent link to this record |