A5045186492- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Mass Spectrometry Techniques and Applications
- Analytical Chemistry and Chromatography
- Air Quality and Health Impacts
- Indoor Air Quality and Microbial Exposure
- Natural product bioactivities and synthesis
- Phytochemistry and Biological Activities
- Traditional and Medicinal Uses of Annonaceae
- Atmospheric aerosols and clouds
- Eicosanoids and Hypertension Pharmacology
- Plant biochemistry and biosynthesis
- Analytical chemistry methods development
- Phytochemicals and Antioxidant Activities
- Ion-surface interactions and analysis
- Advanced Chemical Sensor Technologies
- Inflammatory mediators and NSAID effects
- Neuropeptides and Animal Physiology
- Air Quality Monitoring and Forecasting
- Vehicle emissions and performance
- Odor and Emission Control Technologies
- Bioactive natural compounds
- DNA and Nucleic Acid Chemistry
- Peroxisome Proliferator-Activated Receptors
- Morinda citrifolia extract uses
UCLouvain
2025
Centre National de Recherches Météorologiques
2015-2024
Météo-France
2015-2024
Centre National de la Recherche Scientifique
2012-2024
Université de Toulouse
2012-2024
University of Antwerp
2011-2021
Laboratoire de l'Atmosphère et des Cyclones
2018
Leibniz Institute for Tropospheric Research
2007-2013
Laboratoire d'Analyse et d'Architecture des Systèmes
2012
California Institute of Technology
2006-2010
Abstract. Secondary organic aerosol (SOA) accounts for a significant fraction of ambient tropospheric and detailed knowledge the formation, properties transformation SOA is therefore required to evaluate its impact on atmospheric processes, climate human health. The chemical physical processes associated with formation are complex varied, and, despite considerable progress in recent years, quantitative predictive understanding does not exist represents major research challenge science. This...
Detailed organic analysis of natural aerosols from the Amazonian rain forest showed considerable quantities previously unobserved polar compounds, which were identified as a mixture two diastereoisomeric 2-methyltetrols: 2-methylthreitol and 2-methylerythritol. These polyols, have isoprene skeleton, can be explained by OH radical-initiated photooxidation isoprene. They low vapor pressure, allowing them to condense onto preexisting particles. It is estimated that results in an annual global...
Organosulfates of isoprene, α-pinene, and β-pinene have recently been identified in both laboratory-generated ambient secondary organic aerosol (SOA). In this study, the mechanism ubiquity organosulfate formation biogenic SOA is investigated by a comprehensive series laboratory photooxidation (i.e., OH-initiated oxidation) nighttime oxidation NO3-initiated under dark conditions) experiments using nine monoterpenes (α-pinene, β-pinene, d-limonene, l-limonene, α-terpinene, γ-terpinene,...
Recent work in our laboratory has shown that the photooxidation of isoprene (2-methyl-1,3-butadiene, C(5)H(8)) leads to formation secondary organic aerosol (SOA). In current study, chemical composition SOA from over full range NO(x) conditions is investigated through a series controlled chamber experiments. studied using wide experimental techniques: electrospray ionization-mass spectrometry, matrix-assisted laser desorption high-resolution mass online gas chromatography/mass and an...
Recent work has shown that particle-phase reactions contribute to the formation of secondary organic aerosol (SOA), with enhancements SOA yields in presence acidic seed aerosol. In this study, chemical composition from photooxidations α-pinene and isoprene, or absence sulfate aerosol, is investigated through a series controlled chamber experiments two separate laboratories. By using electrospray ionization−mass spectrometry, esters produced laboratory photooxidation are identified for first...
Atmospheric levoglucosan has been determined as a proxy for “biomass smoke” in samples from six background stations on west–east transect extending the Atlantic (Azores) to mid‐European site KPZ (K‐Puszta, Hungary). Concentration levels of (biannual averages) range 0.005 μ g/m 3 at oceanic AZO 0.52 AVE (Aveiro, Portugal). The atmospheric concentration was derived data with wood‐type‐specific conversion factors. Annual averages wood smoke ranged 0.05 4.3 AVE. Winter (DJF) low‐level sites and...
A mass spectrometric method based on the combined use of fast atom bombardment collisionally-induced dissociation (CID) and tandem spectrometry has been used for structural characterization free conjugated flavone flavonol aglycones. Low-energy CID spectra [M + H]+ (or Y+0) ions show simple fragmentation patterns, which allow substituents in B rings and, particular, differentiation between flavones flavonols. systematic nomenclature product produced from protonated molecules under conditions...
Highly oxygenated compounds assigned to be oxidation products of α ‐pinene have recently been observed in substantial concentrations ambient aerosols. Here, we confirm the unknown tracer compound with molecular weight (MW) 204 as C 8 ‐tricarboxylic acid 3‐methyl‐1,2,3‐butanetricarboxylic acid. Its gas and liquid chromatographic behaviors its mass spectral characteristics electron ionization negative ion electrospray perfectly agree those a synthesized reference compound. The formation this...
The formation of organosulfates from the gas-phase ozonolysis β-pinene in presence neutral or acidic sulfate particles was investigated a series indoor aerosol chamber experiments. were analyzed using high-performance liquid chromatography (LC) coupled to electrospray ionization−time-of-flight mass spectrometry (MS) parallel ion trap MS. Organosulfates only found secondary organic seed particles. One detected also occurred ambient samples that collected at forest site northeastern Bavaria,...
Detailed organic analysis of fine (PM2.5) rural aerosol collected during summer at K-puszta, Hungary from a mixed deciduous/coniferous forest site shows the presence polar oxygenated compounds that are also formed in laboratory irradiated alpha-pinene/NOx/air mixtures. In present work, two major photooxidation products alpha-pinene were characterized as hydroxydicarboxylic acids, 3-hydroxyglutaric acid, and 2-hydroxy-4-isopropyladipic based on chemical, chromatographic, mass spectral data....
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAntimicrobial peptides from Amaranthus caudatus seeds with sequence homology to the cysteine/glycine-rich domain of chitin-binding proteinsWillem F. Broekaert, Wim Marien, Franky R. G. Terras, Miguel C. De Bolle, Paul Proost, Jozef Van Damme, Lieve Dillen, Magda Claeys, Sarah B. Rees, and Cite this: Biochemistry 1992, 31, 17, 4308–4314Publication Date (Print):May 15, 1992Publication History Published online1 May 2002Published inissue 15...
In the present study, we have characterized in detail MS(2) and MS(3) fragmentation behaviors, using electrospray ionization (ESI) negative ion mode, of previously identified sulfated isoprene secondary organic aerosol compounds, including 2-methyltetrols, 2-methylglyceric acid, 2-methyltetrol mononitrate derivatives, glyoxal methylglyoxal. A major pathway for deprotonated molecules sulfate esters 2-methyltetrols acid derivatives methylglyoxal is formation bisulfate [HSO(4)](-) anion, while...
Isomeric flavonoid O-diglycosides were analyzed by positive and negative nano-electrospray ionization (ESI) ion trap mass spectrometry (ITMS) in order to evaluate whether the two most common interglycosidic linkage types, i.e. 1 --> 2 6, found for glycosides containing a rhamnosylglucose glycan part can be differentiated. In mode degree of internal glucose residue loss was strongly dependent on aglycone type very pronounced aglycones flavanone type. The relative abundance Y-type ions formed...
Abstract. In the present study, we have characterized structure of a higher-molecular weight (MW) 358 α- and β-pinene dimeric secondary organic aerosol (SOA) product that received ample attention in previous molecular characterization studies has been elusive. Based on mass spectrometric evidence for deprotonated molecules formed by electrospray ionization negative ion mode chemical considerations, it is suggested diaterpenylic acid key monomeric intermediate dimers ester type. It proposed...
Novel secondary organic aerosol (SOA) products from the monoterpene α-pinene with unique dimer-forming properties have been identified as lactone-containing terpenoic acids, i.e., terpenylic and 2-hydroxyterpenylic acid, diaterpenylic acid acetate. The structural characterizations were based on synthesis of reference compounds detailed interpretation mass spectral data. Terpenylic acetate are early oxidation generated upon both photooxidation ozonolysis, while is an abundant SOA tracer in...
An improved analytical method was developed and validated for the determination of monosaccharide anhydrides levoglucosan, mannosan, galactosan in atmospheric aerosol samples. The uses an external recovery standard, extraction dichloromethane, trimethylsilylation, addition internal standard (1-phenyl dodecane), analysis by gas chromatography with flame ionization detection (GC-FID) chroma tography/mass spectrometry (GC/MS). As we selected 1,2,3-trihydroxyhexane, which has a similar polarity...
Abstract We developed and validated a gas chromatographic/ion trap mass spectrometric method for the determination of levoglucosan related monosaccharide anhydrides, mannosan, galactosan 1,6‐anhydro‐β‐ D ‐glucofuranose in urban atmospheric aerosols collected on quartz fiber filters. The is based extraction with dichloromethane–methanol (80 : 20, v/v), trimethylsilylation, multiple reaction monitoring tandem mode using ion at m / z 217, use an internal standard calibration procedure...