Luc Moens | Ghent University (original) (raw)
Papers by Luc Moens
Journal of Raman Spectroscopy, 2021
Micro-Raman spectroscopy was employed for the analysis of samples collected from the shelters Cam... more Micro-Raman spectroscopy was employed for the analysis of samples collected from the shelters Campo Cerda 1, Angostura Blanca and Campo Moncada 1 located in Piedra Parada valley, Chubut province, Argentinian Patagonia. Different coloured layers, degradation products and rock supports were analysed. Haematite (α-Fe2O3), goethite (α- FeOOH), green earth and gypsum (CaSO4 ·2H2O) were responsible for the main colouration of the pigmented layers together with other components. Gypsum, Caoxalates and calcite were the major degradation materials affecting the rock paintings and the rock support. Different types of silicates, apatite [Ca5(PO4)3(F,Cl,OH)] and goethite were positively characterized in the rock support. Point analysis and micro- Raman mappings contributed towards a better understanding of the materials and layer sequencing of the samples extracted.
TrAC Trends in Analytical Chemistry, 2018
Journal of Raman Spectroscopy, 2017
In the framework of the inter‐disciplinary KongoKing project, a set of beads from archaeological ... more In the framework of the inter‐disciplinary KongoKing project, a set of beads from archaeological excavations in the Democratic Republic of the Congo was analysed by means of a minimally invasive, multi‐analytical approach based on micro‐Raman spectroscopy. The full characterization of the materials, including glassy network, opacifiers and colorizers, was achieved thanks to the combination of data from handheld X‐ray fluorescence, variable pressure scanning electron microscopy coupled with energy‐dispersive X‐ray spectrometry, micro‐Fourier transform infrared spectroscopy and pyrolysis coupled to gas chromatography and mass spectrometry. The obtained chemical information was used to fill the existing gap in the chemical study of beads from Western Central Africa. The cobalt‐rich blue beads were found to be of Central European origin, while the copper‐rich turquoise beads were manufactured using distinct copper sources. Cadmium yellow and cadmium red are the colourants responsible fo...
Journal of Raman Spectroscopy, 2017
Portable Raman spectroscopy is applied for the first time on rock art paintings from hunter‐gathe... more Portable Raman spectroscopy is applied for the first time on rock art paintings from hunter‐gatherers in three different provinces in Patagonia, Argentina (Neuquén, Río Negro and Chubut). Selected archaeological sites were examined, revealing the local ‘palette’ of the native population and, if possible, the technology used. Moreover, alteration products were investigated to obtain valuable information for a better conservation and preservation of these magnificent rock art paintings. During a single research campaign, 16 shelters and one cave were investigated, which makes this study as one of the most condensed expeditions on measuring rock art paintings. Here, we evaluate the use of our portable Raman instrument to analyse rock art paintings under extreme conditions in Patagonia, Argentina. Several improvements are proposed to maximize the quality of the research output in such condensed expeditions. Copyright © 2017 John Wiley & Sons, Ltd.
Journal of Raman Spectroscopy, 2015
In Northwestern Patagonia, many archaeological sites can be found that testify human occupation b... more In Northwestern Patagonia, many archaeological sites can be found that testify human occupation by hunter–gatherer groups during the Holocene period. The general purpose of archaeological research in this area is to obtain information on the movements of these groups between the dry steppe and the different sectors in the forests. This paper reports on the results of the first spectroscopic analysis of samples from the archaeological excavation of two hunter–gatherer regions in Northern Patagonia (Traful Lake and Manso River areas). Thirty samples of rock art fragments, grinding tools, shell, raw pigment material, as well as painted ceramics and beads were examined with micro‐Raman spectroscopy, complemented with X‐ray fluorescence (XRF) analysis. Micro‐Raman analysis revealed mostly the use of haematite (Fe2O3) as the red chromophore. The presence of associated minerals and silicates indicated that clay‐like material (ochre) was used, instead of pure haematite. Although not fully c...
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2011
Rapid Communications in Mass Spectrometry, 2011
Proteomics techniques are increasingly applied for the identification of protein binders in histo... more Proteomics techniques are increasingly applied for the identification of protein binders in historical paints. The complex nature of paint samples, with different kinds of pigments mixed into, and degradation by long term exposure to light, humidity and temperature variations, requires solid analysis and interpretation methods. In this study matrix‐assisted laser desorption/ionisation time‐of‐flight (MALDI‐TOF) mass spectra of tryptic‐digested paint replicas are subjected to principal component analysis (PCA) and soft independent modelling of class analogy (SIMCA) in order to distinguish proteinaceous binders based on animal glues, egg white, egg yolk and milk casein from each other. The most meaningful peptide peaks for a given protein class will be determined, and if possible, annotated with their corresponding amino acid sequence. The methodology was subsequently applied on egg temperas, as well as on animal glues from different species. In the latter small differences in the MAL...
Journal of Analytical Atomic Spectrometry, 2002
ABSTRACT In this work, a method has been developed for the fast and reliable determination of sil... more ABSTRACT In this work, a method has been developed for the fast and reliable determination of silicon in polyamides (two samples with silicon contents of 10 and 50 µg g−1 were analyzed) by means of solid sampling electrothermal vaporization ICP-MS. For all silicon isotopes, the occurrence of spectral interferences was studied as a function of the vaporization temperature. The benefits of the use of palladium as a chemical modifier were investigated. Finally, a vaporization temperature of 2400 °C, monitoring of 29Si+ and the addition of 1 µg of palladium were found to be the optimum conditions for the determination. The method finally proposed shows very interesting features for this particular element: the ability to use aqueous standard solutions for calibration, a low sample consumption (a few milligrams only), a high sample throughput (20 min analysis time per sample), a low limit of detection (0.3 µg g−1) and a reduced risk of analyte losses and, particularly, of contamination. Additionally, the approach also exhibits multi-element capabilities.
Journal of Analytical Atomic Spectrometry, 2001
ABSTRACT Electrothermal vaporization (ETV) ICP mass spectrometry is a method that combines the ab... more ABSTRACT Electrothermal vaporization (ETV) ICP mass spectrometry is a method that combines the ability of the graphite furnace to handle complex samples with the detection power of ICP-MS. It is somewhat surprising, however, that most works reporting on the application of this method have only described the “simultaneous” (from the same tube firing) determination of 1–3 elements. Different authors have attributed this fact to the limited capability of the quadrupole filter (the most commonly used mass spectrometer in ICP-MS instrumentation) to deal with the transient signals that electrothermal vaporization produces. Nevertheless, recent works suggest that the real multi-element capabilities of ETV quadrupole-based ICP-MS might have been largely underestimated. A systematic study of the number of mass-to-charge ratios that can be “simultaneously” monitored in ETV quadrupole-based ICP-MS without degrading the precision, the sensitivity and the limits of detection has been carried out. Three elements with different furnace behaviours (Cd, Co and Ti) were chosen for the study. The effect of the dwell time and the way of processing the analytical data were also evaluated. The results indicate that, when using ETV-ICP-MS with a quadrupole-based instrument, no detrimental effects on the precision, detection limits and sensitivity occur as long as a critical value of three or four points to define the signal profile is achieved. This requirement corresponds to the possibility of monitoring more than 20 elements for a standard peak width of 1.5–2 s. Several options for further improvements are also discussed, including the possibility of separating (with respect to time) the vaporization of elements with different furnace behaviours.
Journal of Analytical Atomic Spectrometry, 2001
ABSTRACT It is known that the accurate determination of ppm levels of sulfur in solid samples is ... more ABSTRACT It is known that the accurate determination of ppm levels of sulfur in solid samples is very complicated. One of the approaches that have been evaluated in order to improve the detection limits for this element is the use of electrothermal vaporization (ETV) as an alternative means of sample introduction in ICP mass spectrometry. In this way, it is possible to achieve a significant decrease of the oxygen-based interferences. In this work, the possibilities of electrothermal vaporization ICP-MS for sulfur determination are extended one step further, as the direct determination of the analyte in two Bisphenol samples (about 0.3 and 2 µg g−1) is carried out. Bisphenol A is a precursor in the production of polycarbonate and epoxy resins, in which sulfur is present as an impurity. 34S was the isotope selected for the determination. Palladium (0.5 µg) was found to be the best chemical modifier and is capable of both preventing analyte losses (up to a pyrolysis temperature of 400°C) and improving the sensitivity. Some evidence as to the way in which it may act is also presented. Nitric acid was added as well in order to favour an efficient matrix removal prior to the release of the analyte. The resulting solid sampling-electrothermal vaporization-ICP-MS method combines very interesting features for this particular element: a high sample throughput (20–25 min per sample), a low limit of detection (4 ng g−1) and a reduced risk of analyte losses and/or contamination. Moreover, it presents some advantages over the dedicated sulfur analyzers that are very popular in the industry: low sample consumption (a few milligrams), multi-element possibilities and the ability to use aqueous standard solutions for calibration. On the other hand, the overall method cannot be considered as very economic, but, for many laboratories that already own an ICP-MS instrument, the acquisition of an ETV device would be relatively inexpensive.
Journal of Analytical Atomic Spectrometry, 2003
European Journal of Inorganic Chemistry, 1998
Analytical Chemistry, 2000
Journal of Raman Spectroscopy, 2021
Micro-Raman spectroscopy was employed for the analysis of samples collected from the shelters Cam... more Micro-Raman spectroscopy was employed for the analysis of samples collected from the shelters Campo Cerda 1, Angostura Blanca and Campo Moncada 1 located in Piedra Parada valley, Chubut province, Argentinian Patagonia. Different coloured layers, degradation products and rock supports were analysed. Haematite (α-Fe2O3), goethite (α- FeOOH), green earth and gypsum (CaSO4 ·2H2O) were responsible for the main colouration of the pigmented layers together with other components. Gypsum, Caoxalates and calcite were the major degradation materials affecting the rock paintings and the rock support. Different types of silicates, apatite [Ca5(PO4)3(F,Cl,OH)] and goethite were positively characterized in the rock support. Point analysis and micro- Raman mappings contributed towards a better understanding of the materials and layer sequencing of the samples extracted.
TrAC Trends in Analytical Chemistry, 2018
Journal of Raman Spectroscopy, 2017
In the framework of the inter‐disciplinary KongoKing project, a set of beads from archaeological ... more In the framework of the inter‐disciplinary KongoKing project, a set of beads from archaeological excavations in the Democratic Republic of the Congo was analysed by means of a minimally invasive, multi‐analytical approach based on micro‐Raman spectroscopy. The full characterization of the materials, including glassy network, opacifiers and colorizers, was achieved thanks to the combination of data from handheld X‐ray fluorescence, variable pressure scanning electron microscopy coupled with energy‐dispersive X‐ray spectrometry, micro‐Fourier transform infrared spectroscopy and pyrolysis coupled to gas chromatography and mass spectrometry. The obtained chemical information was used to fill the existing gap in the chemical study of beads from Western Central Africa. The cobalt‐rich blue beads were found to be of Central European origin, while the copper‐rich turquoise beads were manufactured using distinct copper sources. Cadmium yellow and cadmium red are the colourants responsible fo...
Journal of Raman Spectroscopy, 2017
Portable Raman spectroscopy is applied for the first time on rock art paintings from hunter‐gathe... more Portable Raman spectroscopy is applied for the first time on rock art paintings from hunter‐gatherers in three different provinces in Patagonia, Argentina (Neuquén, Río Negro and Chubut). Selected archaeological sites were examined, revealing the local ‘palette’ of the native population and, if possible, the technology used. Moreover, alteration products were investigated to obtain valuable information for a better conservation and preservation of these magnificent rock art paintings. During a single research campaign, 16 shelters and one cave were investigated, which makes this study as one of the most condensed expeditions on measuring rock art paintings. Here, we evaluate the use of our portable Raman instrument to analyse rock art paintings under extreme conditions in Patagonia, Argentina. Several improvements are proposed to maximize the quality of the research output in such condensed expeditions. Copyright © 2017 John Wiley & Sons, Ltd.
Journal of Raman Spectroscopy, 2015
In Northwestern Patagonia, many archaeological sites can be found that testify human occupation b... more In Northwestern Patagonia, many archaeological sites can be found that testify human occupation by hunter–gatherer groups during the Holocene period. The general purpose of archaeological research in this area is to obtain information on the movements of these groups between the dry steppe and the different sectors in the forests. This paper reports on the results of the first spectroscopic analysis of samples from the archaeological excavation of two hunter–gatherer regions in Northern Patagonia (Traful Lake and Manso River areas). Thirty samples of rock art fragments, grinding tools, shell, raw pigment material, as well as painted ceramics and beads were examined with micro‐Raman spectroscopy, complemented with X‐ray fluorescence (XRF) analysis. Micro‐Raman analysis revealed mostly the use of haematite (Fe2O3) as the red chromophore. The presence of associated minerals and silicates indicated that clay‐like material (ochre) was used, instead of pure haematite. Although not fully c...
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2011
Rapid Communications in Mass Spectrometry, 2011
Proteomics techniques are increasingly applied for the identification of protein binders in histo... more Proteomics techniques are increasingly applied for the identification of protein binders in historical paints. The complex nature of paint samples, with different kinds of pigments mixed into, and degradation by long term exposure to light, humidity and temperature variations, requires solid analysis and interpretation methods. In this study matrix‐assisted laser desorption/ionisation time‐of‐flight (MALDI‐TOF) mass spectra of tryptic‐digested paint replicas are subjected to principal component analysis (PCA) and soft independent modelling of class analogy (SIMCA) in order to distinguish proteinaceous binders based on animal glues, egg white, egg yolk and milk casein from each other. The most meaningful peptide peaks for a given protein class will be determined, and if possible, annotated with their corresponding amino acid sequence. The methodology was subsequently applied on egg temperas, as well as on animal glues from different species. In the latter small differences in the MAL...
Journal of Analytical Atomic Spectrometry, 2002
ABSTRACT In this work, a method has been developed for the fast and reliable determination of sil... more ABSTRACT In this work, a method has been developed for the fast and reliable determination of silicon in polyamides (two samples with silicon contents of 10 and 50 µg g−1 were analyzed) by means of solid sampling electrothermal vaporization ICP-MS. For all silicon isotopes, the occurrence of spectral interferences was studied as a function of the vaporization temperature. The benefits of the use of palladium as a chemical modifier were investigated. Finally, a vaporization temperature of 2400 °C, monitoring of 29Si+ and the addition of 1 µg of palladium were found to be the optimum conditions for the determination. The method finally proposed shows very interesting features for this particular element: the ability to use aqueous standard solutions for calibration, a low sample consumption (a few milligrams only), a high sample throughput (20 min analysis time per sample), a low limit of detection (0.3 µg g−1) and a reduced risk of analyte losses and, particularly, of contamination. Additionally, the approach also exhibits multi-element capabilities.
Journal of Analytical Atomic Spectrometry, 2001
ABSTRACT Electrothermal vaporization (ETV) ICP mass spectrometry is a method that combines the ab... more ABSTRACT Electrothermal vaporization (ETV) ICP mass spectrometry is a method that combines the ability of the graphite furnace to handle complex samples with the detection power of ICP-MS. It is somewhat surprising, however, that most works reporting on the application of this method have only described the “simultaneous” (from the same tube firing) determination of 1–3 elements. Different authors have attributed this fact to the limited capability of the quadrupole filter (the most commonly used mass spectrometer in ICP-MS instrumentation) to deal with the transient signals that electrothermal vaporization produces. Nevertheless, recent works suggest that the real multi-element capabilities of ETV quadrupole-based ICP-MS might have been largely underestimated. A systematic study of the number of mass-to-charge ratios that can be “simultaneously” monitored in ETV quadrupole-based ICP-MS without degrading the precision, the sensitivity and the limits of detection has been carried out. Three elements with different furnace behaviours (Cd, Co and Ti) were chosen for the study. The effect of the dwell time and the way of processing the analytical data were also evaluated. The results indicate that, when using ETV-ICP-MS with a quadrupole-based instrument, no detrimental effects on the precision, detection limits and sensitivity occur as long as a critical value of three or four points to define the signal profile is achieved. This requirement corresponds to the possibility of monitoring more than 20 elements for a standard peak width of 1.5–2 s. Several options for further improvements are also discussed, including the possibility of separating (with respect to time) the vaporization of elements with different furnace behaviours.
Journal of Analytical Atomic Spectrometry, 2001
ABSTRACT It is known that the accurate determination of ppm levels of sulfur in solid samples is ... more ABSTRACT It is known that the accurate determination of ppm levels of sulfur in solid samples is very complicated. One of the approaches that have been evaluated in order to improve the detection limits for this element is the use of electrothermal vaporization (ETV) as an alternative means of sample introduction in ICP mass spectrometry. In this way, it is possible to achieve a significant decrease of the oxygen-based interferences. In this work, the possibilities of electrothermal vaporization ICP-MS for sulfur determination are extended one step further, as the direct determination of the analyte in two Bisphenol samples (about 0.3 and 2 µg g−1) is carried out. Bisphenol A is a precursor in the production of polycarbonate and epoxy resins, in which sulfur is present as an impurity. 34S was the isotope selected for the determination. Palladium (0.5 µg) was found to be the best chemical modifier and is capable of both preventing analyte losses (up to a pyrolysis temperature of 400°C) and improving the sensitivity. Some evidence as to the way in which it may act is also presented. Nitric acid was added as well in order to favour an efficient matrix removal prior to the release of the analyte. The resulting solid sampling-electrothermal vaporization-ICP-MS method combines very interesting features for this particular element: a high sample throughput (20–25 min per sample), a low limit of detection (4 ng g−1) and a reduced risk of analyte losses and/or contamination. Moreover, it presents some advantages over the dedicated sulfur analyzers that are very popular in the industry: low sample consumption (a few milligrams), multi-element possibilities and the ability to use aqueous standard solutions for calibration. On the other hand, the overall method cannot be considered as very economic, but, for many laboratories that already own an ICP-MS instrument, the acquisition of an ETV device would be relatively inexpensive.
Journal of Analytical Atomic Spectrometry, 2003
European Journal of Inorganic Chemistry, 1998
Analytical Chemistry, 2000