Research Interests: Archaeology, Art, Painting, Nature, Analysis, and 6 moreOil, Pigment, Function, EST, Hydrolysis, and Infrared Spectrum
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... These include the careful squeezing of a multi-layer sample in ... A Leica DJVLRX analytical microscope (Leica Inc., Wetzlar, Germany) was used for visible light micro scopy. ... al. [34] indicating the presence of linseed oil used... more
... These include the careful squeezing of a multi-layer sample in ... A Leica DJVLRX analytical microscope (Leica Inc., Wetzlar, Germany) was used for visible light micro scopy. ... al. [34] indicating the presence of linseed oil used with out heat-treatment. ...
Research Interests: Archaeology, Stratigraphy, Art, Structure, Painting, and 8 moreSample Preparation, Film, Information, Analysis, Method, Technique, Sample, and EST
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Different mass spectrometric approaches were used to identify an original non-terpenoid varnish. Direct temperature-resolved MS and pyrolysis-GC/MS mainly showed the phenolic components, whereas thermally assisted (trans)methylation with... more
Different mass spectrometric approaches were used to identify an original non-terpenoid varnish. Direct temperature-resolved MS and pyrolysis-GC/MS mainly showed the phenolic components, whereas thermally assisted (trans)methylation with tetramethylammonium hydroxide (TMAH) strongly enhanced the evidence for tung oil as part of the varnish. Transethylation studies of the fatty acids confirmed the TMAH data. The degree of hydrolysis of the oil network was found to be low. No evidence was found for a direct link between the drying oil and phenolic resin. On the basis of the MS information, the aged varnish is identified as an open-structure tert-butylphenol-formaldehyde resin which entangles the tung oil polymer.
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Jaap J. Boon and Elke Oberthaler: Mechanical weakness and paint reactivity observed in the paint structure and surface of The Art of Painting by Vermeer In: Vermeer, Die Malkunst – Spurensicherung an einem Meisterwerk : Ausstellungskatalog des Kunsthistorischen Museums Wien 2010 / ed. Sabine Haag...more
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The depth-profiles of aged triterpenoid resin films, dammar and mastic, were uncovered by optimized krypton fluoride excimer laser ablation (248nm, 25ns) and the etched varnishes were examined by high performance size exclusion... more
The depth-profiles of aged triterpenoid resin films, dammar and mastic, were uncovered by optimized krypton fluoride excimer laser ablation (248nm, 25ns) and the etched varnishes were examined by high performance size exclusion chromatography (HP-SEC). The use of two detectors monitored the molecular weight distribution across depth as a function of absorbance at ultraviolet (240nm) and visible (400nm) light. The absorption of the films at both wavelengths is separated in a small fraction of sesquiterpenoids (200Da), triterpenoid molecules (400/500Da), dimerized and oxidized triterpenoid molecules (900–1000Da) and condensed entities (10–80kDa) that are formed upon the radical polymerization of polycadinene and cis-1,4-poly-β-myrcene, which are the polymers of dammar and mastic, respectively. The results establish the generation of depth-dependent gradients in radical polymerization, condensation and cross-linking across the depth-profiles of the triterpenoid films as a consequence o...
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Research Interests: Archaeology, Art, Painting, Nature, Analysis, and 6 moreOil, Pigment, Function, EST, Hydrolysis, and Infrared Spectrum
... Authors: Israel, Guy; Chassefiere, E.; Niemann, Hasso B.; Boon, Jaap J.; Mueller, Christian; Raulin, Francois; Cabane, M.; Sable, Claude. ... voor Atoom-en Molecuulfysica, Amsterdam, Netherlands), AE(Institut d'Aeronomie Spatiale... more
... Authors: Israel, Guy; Chassefiere, E.; Niemann, Hasso B.; Boon, Jaap J.; Mueller, Christian; Raulin, Francois; Cabane, M.; Sable, Claude. ... voor Atoom-en Molecuulfysica, Amsterdam, Netherlands), AE(Institut d'Aeronomie Spatiale de Belgique, Brussels.), AF(Paris XII Univ ...
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Fourier-transform ion cyclotron resonance mass spectrometry (FTICR-MS) by external injection of matrix-assisted laser desorbed and ionized (MALDI) polymers offers good possibilities for characterization of low molecular weight... more
Fourier-transform ion cyclotron resonance mass spectrometry (FTICR-MS) by external injection of matrix-assisted laser desorbed and ionized (MALDI) polymers offers good possibilities for characterization of low molecular weight homopolymers (MW range up to 10 kDa). The molecular masses of the molecular weight distribution (MWD) components of underivatized and derivatized (dimethyl, dipropyl, dibutyl and diacetyl) polyethylene glycol (PEG) 1000 and 4000 were measured by MALDI-FTICR-MS. These measurements have been performed using a commercial FTICR spectrometer with a home-built external ion source. MALDI of the samples with a 2,5-dihydroxybenzoic acid matrix in a 1000:1 matrix-to-analyte molar ratio produces sodiated molecules in a sufficient yield to trap the ions in the ICR cell. The masses of the molecular weight distribution of PEG components were measured in broad-band mode with a mass accuracy of < 5 ppm in the mass range around 1000 u and within 40 ppm accuracy around 4000 u. From these measurements, the endgroup mass of the polymer was determined by correlation of the measured component mass with the degree of polymerization. The masses of the PEG endgroups have been determined within a deviation of 3-10 millimass units for the PEG1000 derivatives and 10-100 millimass units for the PEG4000 derivatives, thus confirming the identity of the distal parts of the model compounds.
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ABSTRACT Siegburgite, an unusual Tertiary aromatic resin found near Bitterfeld (Germany), has been characterised earlier by FTIR spectrometry as polystyrene-like material. Here the molecular weight distribution of the soluble part is... more
ABSTRACT Siegburgite, an unusual Tertiary aromatic resin found near Bitterfeld (Germany), has been characterised earlier by FTIR spectrometry as polystyrene-like material. Here the molecular weight distribution of the soluble part is determined by size-exclusion chromatography (SEC) to be bomodal with maxima at 400 and 30,000 Da. Using combined gas chromatographic-mass spectrometric techniques (GC–MS) traces of oleanonic and 3-epi-oleanolic acid are found in the low MW fraction of Siegburgite. 3-Phenylpropanylcinnamate is detected in the high MW fraction by pyrolysis (Py)–GC–MS. Although also present in the soluble part of the high MW fraction, this compound is present especially in the insoluble residue, indicating that the ester is incorporated in the polymer chain. Oleanonic acid, 3-epi-oleanolic acid and 3-phenylpropanylcinnamate are constituents of commercially available Gum Storax from modern Liquidambar orientalis Mills. The proposed paleobotanical origin of Siegburgite from the Hammamelidacae family is thus chemically confirmed. In addition, a comparable polystyrene-like resin originating from North America (Squankum New Jersey) was compared to Siegburgite. The polystyrene matrix of this resin is comparable to that of Siegburgite, but no molecular markers confirming its origin could be found.
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Scanning electron microscopy backscattered-electron images of paint cross sections show the compositional contrast within the paint system. They not only give valuable information about the pigment composition and layer structure but also... more
Scanning electron microscopy backscattered-electron images of paint cross sections show the compositional contrast within the paint system. They not only give valuable information about the pigment composition and layer structure but also about the aging processes in the paint. This article focuses on the reading of backscatter images of lead white-containing samples from traditional oil paintings (17th–19th centuries). In contrast to modern lead white, traditional stack process lead white is characterized by a wide particle size distribution. Changes in particle morphology and distribution are indications of chemical/physical reactivity in the paint. Lead white can be affected by free fatty acids to form lead soaps. The dissolution of lead white can be recognized in the backscatter image by gray (less scattering) peripheries around particles and gray amorphous areas as opposed to the well-defined, highly scattering intact lead white particles. The small particles react away first, ...
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ABSTRACT Matrix-assisted laser desorption/ionization (MALDI) and Fourier-transform ion cyclotron mass spectrometry (FT-ICR-MS) are combined for the characterization of polyoxyalkyleneamines. 1H and 13C NMR data are used to confirm and... more
ABSTRACT Matrix-assisted laser desorption/ionization (MALDI) and Fourier-transform ion cyclotron mass spectrometry (FT-ICR-MS) are combined for the characterization of polyoxyalkyleneamines. 1H and 13C NMR data are used to confirm and quantify structural assignments. Characterization of the molecular weight distribution, chemical composition distribution, and end group distribution of amine-terminated (co-)polymers of ethylene oxide and propylene oxide is rather complex because the convolution of these three entities yields an ensemble of structurally related molecules which is hard to characterize by conventional analytical techniques. In this study MALDI FT-ICR-MS is used to resolve intact, Na+ cationized, oligomer ions in the mass range from m/z 500 to 3500. This revealed the presence of various compositional distributions in the polyoxyalkyleneamines. The individual compound masses in the molecular weight distributions were measured with a mass accuracy of <20 millimass units, allowing end group and repeat unit determination with an accuracy of better than 50 millimass units. NMR is used to measure the average end group distribution to provide insight in conformational differences. In this respect, FT-ICR-MS data and NMR data are complementary. The combined results yield detailed information about chemical composition distributions of polyoxyalkyleneamines that hitherto it was not possible to obtain with either technique separately.
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A microbial assay and in-source pyrolysis mass spectrometry were used to demonstrate a shift in the characteristics of sestonic particulate organic matter after tidal inundation of a coastal salt marsh in the southwest Netherlands.... more
A microbial assay and in-source pyrolysis mass spectrometry were used to demonstrate a shift in the characteristics of sestonic particulate organic matter after tidal inundation of a coastal salt marsh in the southwest Netherlands. Analysis of seston samples collected from the main tidal creek of the marsh during a series of tidal cycles showed that an increase in microbial degradability accompanied a more pronounced lipid character of the seston after inundation. No evidence was found that the halophyte vegetation contributed to the efflux ...
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Diterpenoid resins from larch and pine trees and the corresponding fractions in a >100-year-old wax-resin adhesive and varnish and a 200-year-old resin/oil paint sample were analysed with by gas chromatography/mass spectrometry... more
Diterpenoid resins from larch and pine trees and the corresponding fractions in a >100-year-old wax-resin adhesive and varnish and a 200-year-old resin/oil paint sample were analysed with by gas chromatography/mass spectrometry (GC/MS) using several off-line and on-line derivatization methods. The main resin compounds were highly oxidized abietic acids. Important products found are hydroxydehydroabietic acids (OH-DHAs), 7-oxoDHA, di-OH-DHAs and 15-OH-7-oxoDHA. The last two compounds have not been reported to occur in artworks before. Larixyl acetate, an important marker from larch resins, was found to be still present in high amounts in the adhesive. A large number of mass spectra of the different oxidation products and larixol and larixyl acetate are presented and their fragmentation behaviour under electron impact conditions is discussed. An index for the degree of oxidation (IDOX) of the abietic acids is presented as an indicator of the degree of oxidation of the matrix in which the resin is present. The IDOX was 0.10, 0.67, 0.81 and 0.76 for the fresh resins, the dark-aged adhesive, the aged varnish and the resin/oil paint, respectively (measured with pyrolysis (Py)-tetramethylammonium hydroxide (TMAH)-GC/MS). Py-TMAH-GC/MS and direct temperature-resolved mass spectrometry are reliable, valuable and fast techniques for the assessment of the presence and degree of oxidation of diterpenoid resins. Copyright 2000 John Wiley & Sons, Ltd.
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The molecular structure of a series of homo- and copolyesters was studied using sustained off-resonance irradiation collisionally activation dissociation on a Fourier transform ion cyclotron resonance mass spectrometer. Electrospray... more
The molecular structure of a series of homo- and copolyesters was studied using sustained off-resonance irradiation collisionally activation dissociation on a Fourier transform ion cyclotron resonance mass spectrometer. Electrospray ionization was used as an ionization technique. The most important fragmentation pathways of the homopolyesters poly(dipropoxylated bisphenol-A/adipic acid) and poly(dipropoxylated bisphenol-A/isophthalic acid) were studied. Six different dissociation mechanisms were observed which are very similar to the mechanisms found to occur during pyrolysis of these compounds. Four of these mechanisms are a result of cleavages of the ester bond and the others are due to cleavages of the ether bond or bisphenol-A unit. Some of the fragments expected are not present in the spectrum, indicating that each fragment has a specific sodium affinity. Sequence-specific fragments of two of the three copolyester sequences that theoretically can exist were experimentally observed. Fragments that originate from the third sequence are not unique and can also be formed from other sequences. Therefore, it was not possible to determine the presence of the third sequence. Copyright 2000 John Wiley & Sons, Ltd.
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ABSTRACT An aged intermediate varnish sample from `The Girl with the Pearl Earring' by J. Vermeer was analysed by thermally assisted methylation with tetramethylammoniumhydroxide (TMAH) followed by gas chromatography in... more
ABSTRACT An aged intermediate varnish sample from `The Girl with the Pearl Earring' by J. Vermeer was analysed by thermally assisted methylation with tetramethylammoniumhydroxide (TMAH) followed by gas chromatography in combination with mass spectrometry. Using library search of the available mass spectra, only three diterpenoid acids were identified. In addition to methyldehydroabietate, 7-oxo-dehydroabietic acid methyl ester and 7-oxo-15-hydroxy-dehydroabietic acid methyl ester were identified. There was reason to believe that the remaining unidentified compounds might be related to the oxidised derivatives of dehydroabietic acid and are formed upon methylation with TMAH. In order to investigate the behaviour of pure 7-oxo-dehydroabietic acid and 7-oxo-15-hydroxydehydroabietic acid under these specific derivatisation conditions, these compounds were synthesised and isolated. On derivatisation with TMAH, several methylation products, with varying degrees of methylation were formed from each of the pure compounds. Their structures were elucidated using specific fragment ions present in their mass spectra. Unusual products formed by methylation on a carbon atom under these conditions were observed. Based on these comparative studies, 7-oxo-dehydroabietic acid and 7-oxo-15-hydroxy-dehydroabietic acid were identified as the main components of the varnish.
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Naples yellow-containing oil paints aged under natural and artificial conditions were investigated as model systems to evaluate the potential of secondary ion mass spectrometry (SIMS) when used in combination with other mass spectrometric... more
Naples yellow-containing oil paints aged under natural and artificial conditions were investigated as model systems to evaluate the potential of secondary ion mass spectrometry (SIMS) when used in combination with other mass spectrometric and spectroscopic analytical methods. Although the advantage of SIMS is the simultaneous detection of organic and inorganic components and their spatial distribution, the methodology has limitations in compound sensitivity and shows bias towards certain constituents. Gas chromatography–mass spectrometry (GC/MS) shows dicarboxylic fatty acids to be main components in the paint, but SIMS detects these compounds poorly. Electrospray ionisation mass spectrometry (ESI-MS) shows a broad range of glyceryl derivatives of mono- and dicarboxylic fatty acids (mono-, di- and triglyceride derivatives), while SIMS only detects the mono- and diglycerides of the monocarboxylic acids. Compared to SIMS, direct temperature-resolved mass spectrometry (DTMS) offers greater insight into how the various constituents are incorporated into the paint film, but SIMS data supports the information provided by Fourier transform infrared (FTIR) on metal soap formation. The surface sensitivity of SIMS is an advantage for probing paint constituent distributions and was exploited to examine variations in the composition of the top and bottom of a paint film, and the spatial correlation between metal and fatty acid composition in metal soap aggregates. Disadvantages of SIMS are the low yields and matrix dependency of the organic species in the paint matrix. Application of an ultra-thin gold coating overcomes this, and enhances the organic secondary ion yields leading to more accurate spatial distribution.
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A series of kerogens and kerogen precursors isolated from DSDP samples, oil shales and Recent algal mats have been examined by Curie point pyrolysis-high resolution gas chromatography and gas chromatography-mass spectrometry. This study... more
A series of kerogens and kerogen precursors isolated from DSDP samples, oil shales and Recent algal mats have been examined by Curie point pyrolysis-high resolution gas chromatography and gas chromatography-mass spectrometry. This study has shown that the three main ...