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Author |
Neven, L.; Barich, H.; Rutten, R.; De Wael, K. |
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Title |
Novel (photo)electrochemical analysis of aqueous industrial samples containing phenols |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Microchemical journal |
Abbreviated Journal |
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Volume |
181 |
Issue |
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Pages |
107778-11 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
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Abstract |
Phenols are considered as toxic pollutants and their discharge into the environment by industries is regulated by a concentration limit. As these limits are in the low mg L−1 to µg L−1-range, sensitive methods are necessary to detect these phenols. Here, aqueous industrial phenolic samples throughout a cleaning process were analyzed by two novel electrochemical sensors. Both the photoelectrochemical (PEC) sensor and the square wave voltammetric (SWV) sensor could successfully follow the decrease of the concentration of phenols along the industrial cleaning process. The discharge sample (μg L−1) could only be analyzed by the PEC sensor and not by the SWV sensor, as the phenolic concentration was close to the LOD of the latter. With HPLC-diode array detector (DAD) measurements, classical phenols such as phenol (PHOH), hydroquinone, resorcinol and o-cresol could be identified in the industrial samples, and their presence could be linked to the electrochemical responses. At last, the performance of the PEC and SWV sensors were compared with commercial colorimetric and chemical oxygen demand (COD) test kits. This comparison demonstrated the high sensitivity of the PEC sensor in the μg L−1 concentrated phenolic samples. Together with the identification of the redox peaks through HPLC-DAD analysis, the SWV sensor can be a powerful tool in the qualitative analysis of mg L−1 concentrated phenolic samples due to its speed, simplicity and absence of laborious sample pre-treatment steps. |
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Wos |
000837838400003 |
Publication Date |
2022-07-20 |
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0026-265x; 0026-265x |
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Additional Links |
UA library record; WoS full record |
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Open Access |
OpenAccess |
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no |
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Call Number |
UA @ admin @ c:irua:189428 |
Serial |
8906 |
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Author |
Schram, J.; Parrilla, M.; Slosse, A.; Van Durme, F.; Åberg, J.; Björk, K.; Bijvoets, S.M.; Sap, S.; Heerschop, M.W.J.; De Wael, K. |
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Title |
Paraformaldehyde-coated electrochemical sensor for improved on-site detection of amphetamine in street samples |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Microchemical journal |
Abbreviated Journal |
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Volume |
179 |
Issue |
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Pages |
107518-107519 |
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Keywords |
A1 Journal article; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
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Abstract |
The increasing illicit production, distribution and abuse of amphetamine (AMP) poses a challenge for law enforcement worldwide. To effectively combat this issue, fast and portable tools for the on-site screening of suspicious samples are required. Electrochemical profile (EP)-based sensing of illicit drugs has proven to be a viable option for this purpose as it allows rapid voltammetric measurements via the use of disposable and low-cost graphite screen-printed electrodes (SPEs). In this work, a highly practical paraformaldehyde (PFA)-coated sensor, which unlocks the detectability of primary amines through derivatization, is developed for the on-site detection of AMP in seized drug samples. A potential interval was defined at the sole AMP peak (which is used for identification of the target analyte) to account for potential shifts due to fluctuations in concentration and temperature, which are relevant factors for on-site use. Importantly, it was found that AMP detection was not hindered by the presence of common diluents and adulterants such as caffeine, even when present in high amounts. When inter-drug differentiation is desired, a simultaneous second test with the same solution on an unmodified electrode is introduced to provide the required additional electrochemical information. Finally, the concept was validated by analyzing 30 seized AMP samples (reaching a sensitivity of 96.7 %) and comparing its performance to that of commercially available Raman and Fourier Transform Infrared (FTIR) devices. |
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Wos |
000809675500010 |
Publication Date |
2022-04-26 |
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ISSN |
0026-265x; 0026-265x |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
OpenAccess |
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no |
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Call Number |
UA @ admin @ c:irua:188454 |
Serial |
8910 |
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Author |
Van Echelpoel, R.; Parrilla, M.; Sleegers, N.; Thiruvottriyur Shanmugam, S.; van Nuijs, A.L.N.; Slosse, A.; Van Durme, F.; De Wael, K. |
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Title |
Validated portable device for the qualitative and quantitative electrochemical detection of MDMA ready for on-site use |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Microchemical journal |
Abbreviated Journal |
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Volume |
190 |
Issue |
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Pages |
108693-10 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Toxicological Centre; Antwerp Electrochemical and Analytical Sciences Lab (A-Sense Lab) |
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Abstract |
Identifying and quantifying 3,4-methylenedioxymethamphetamine (MDMA) on-site in suspected illicit drug samples, whether it be at recreational settings or manufacturing sites, is a major challenge for law enforcement agencies (LEAs). Various analytical techniques exist to fulfil this goal, e.g. colourimetry and portable spectroscopic techniques, each having its specific limitations (e.g. low accuracy, fluorescence, no quantification) and strengths (e.g. fast, easy to use). In this work, for the first time, an electrochemical MDMA sensor is presented to become a detection tool that can realistically be used on-site. More specifically, the use of a single buffer solution and an unmodified screen-printed electrode, along with the integration of a data analysis algorithm and mobile application permits the straightforward on-site identification and quantification of MDMA in suspicious samples. Multiple studies investigating different parameters, including pH, concentration, reproducibility, temperature and binary mixture analyses, were executed. To fully understand all the occurring redox processes, liquid chromatography coupled with high-resolution mass spectrometry analysis of partially electrolyzed MDMA samples was performed unravelling oxidation of the methylenedioxy group. Validation of the methodology was executed on 15 MDMA street samples analysed by gas chromatography coupled with mass spectrometry and compared with the performance of a commercial portable Raman and Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) device. The novel methodology outperformed the spectroscopic techniques, correctly identifying all 15 street samples. Additionally, the electrochemical sensor predicted the purity of the tablets with a mean absolute error of 2.3%. Overall, this new, electrochemical detection strategy provides LEAs the rapid, low-cost, on-site detection and quantification of MDMA in suspicious samples, without requiring specialized training. |
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Wos |
000977060400001 |
Publication Date |
2023-03-31 |
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Edition |
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ISSN |
0026-265x; 0026-265x |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.8 |
Times cited |
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Open Access |
OpenAccess |
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Approved |
Most recent IF: 4.8; 2023 IF: 3.034 |
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Call Number |
UA @ admin @ c:irua:195415 |
Serial |
8952 |
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Author |
Pastorelli, G.; Miranda, A.S.O.; Avranovich Clerici, E.; d'Imporzano, P.; Hansen, B.V.; Janssens, K.; Davies, G.R.; Borring, N. |
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Title |
Darkening of lead white in old master drawings and historic prints : a multi-analytical investigation |
Type |
A1 Journal article |
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Year |
2024 |
Publication |
Microchemical journal |
Abbreviated Journal |
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Volume |
199 |
Issue |
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Pages |
109912-10 |
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Keywords |
A1 Journal article; Antwerp X-ray Imaging and Spectroscopy (AXIS) |
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Abstract |
Old master drawings and historic prints often feature white highlights, which are typically painted using lead white, one of the most widely used historical white pigments. However, it has been observed that many of these highlights discolour over time, becoming dark brown or black due to unclear degradation processes. This phenomenon not only misrepresents the original artefacts, threatening their suitability for public display, but also diminishes their longevity. To ensure their preservation, it is essential to determine why some lead white highlights in these museum objects retain their light tones while others are prone to darkening. The objective of this study was to identify the relationships between the composition, provenance, and production methods of lead white pigments, and their role in the discolouration observed on drawings, lithographs and early photographs. Selected samples and artefacts were examined using a range of analytical techniques, namely X-ray fluorescence spectroscopy (XRF), X-ray powder diffraction (XRPD), and lead isotope analysis. While XRF analyses confirmed the presence of lead as the primary element in the majority of the highlights, XRPD measurements identified a variety of lead compounds such as the carbonates cerussite and hydrocerussite alongside galena-a black crystalline sulfide-and lead sulfates. Additionally, isotope analyses classified the lead raw materials into five main groups. Through these measurements, the examined lead white pigments were categorised based on their compositional properties in relation to the raw materials used, as well as their geographical and temporal origin. A significant finding is that lead white pigments from different production periods, spanning from older to more modern, may be characterised by varying proneness to discolouration irrespective of their provenance. |
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Wos |
001166502200001 |
Publication Date |
2024-01-03 |
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Series Volume |
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Edition |
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ISSN |
0026-265x; 0026-265x |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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no |
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Call Number |
UA @ admin @ c:irua:205450 |
Serial |
9197 |
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