Found 9886 publications. Showing page 139 of 396:
2024
2014
Nordic nitrogen and agriculture: Policy, measures and recommendations to reduce environmental impact. TemaNord, 2017:547
2017
2023
2015
2019
2013
2023
2025
Non-target screening - a powerful tool for selecting environmental pollutants. NILU OR
The main goal with this project was to test the potential and practicalness of the available non-target screening methods for identification of unknown or new emerging environmental pollutants. It was also desired to try to estimate the quantity of the identified compounds.
2013
Wood building materials can be a source of volatile organic compounds (VOCs) in the indoor environment and increasing focus is put on classification and regulation of the use of wood building materials in Europe. The main wood related VOCs such as monoterpenes rarely pose adverse health effects for humans, but as analytical procedures become more sensitive new hazardous VOCs are detected in low concentration. There is a need for comprehensive identification of VOCs emitting from different wood building materials for indoor use. This study performed a first semi-quantitative non-target and suspect screening of VOC emissions from three important wood-based building materials in Europe. Air samples collected from emission chambers were analyzed using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry and resulting mass spectra were classified into confidence groups. A total of 84, 133 and 197 compounds were found to emit from cross-laminated timber, untreated spruce panel and untreated pine panel, respectively. Pine panel was found to emit a higher number of VOCs as well as higher concentrations of most VOCs compared to the spruce building materials. Several new VOCs were detected in the emission profile of pine and spruce. However, they were mostly structurally similar to previously reported wood VOCs. Two compounds of concern emitting from all three wood building materials were furfural and (E)-2-octenal, as these have been classified as group 2 carcinogen and potent eye irritant, respectively.
Elsevier
2025
2020
Long-term monitoring of regulated organic chemicals, such as legacy persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs), in ambient air provides valuable information about the compounds' environmental fate as well as temporal and spatial trends. This is the foundation to evaluate the effectiveness of national and international regulations for priority pollutants. Extracts of high-volume air samples, collected on glass fibre filters (GFF for particle phase) and polyurethane foam plugs (PUF for gaseous phase), for targeted analyses of legacy POPs are commonly cleaned by treatment with concentrated sulfuric acid, resulting in extracts clean from most interfering compounds and matrices that are suitable for multi-quantitative trace analysis. Such standardised methods, however, severely restrict the number of analytes for quantification and are not applicable when targeting new and emerging compounds as some may be less stable under acid treatment. Recently developed suspect and non-target screening analytical strategies (SUS and NTS, respectively) are shown to be effective evaluation tools aimed at identifying a high number of compounds of emerging concern. These strategies, combining highly sophisticated analytical technology with extensive data interpretation and statistics, are already widely accepted in environmental sciences for investigations of various environmental matrices, but their application to air samples is still very limited. In order to apply SUS and NTS for the identification of organic contaminants in air samples, an adapted and more wide-scope sample clean-up method is needed compared to the traditional method, which uses concentrated sulfuric acid. Analysis of raw air sample extracts without clean-up would generate extensive contamination of the analytical system, especially with PUF matrix-based compounds, and thus highly interfered mass spectra and detection limits which are unacceptable high for trace analysis in air samples.
In this study, a novel wide-scope sample clean-up method for high-volume air samples has been developed and applied to real high-volume air samples, which facilitates simultaneous target, suspect and non-target analyses. The scope and efficiency of the method were quantitatively evaluated with organic compounds covering a wide range of polarities (logP 2–11), including legacy POPs, brominated flame retardants (BFRs), chlorinated pesticides and currently used pesticides (CUPs). In addition, data reduction and selection strategies for SUS and NTS were developed for comprehensive two-dimensional gas chromatography separation with low-resolution time-of-flight mass spectrometric detection (GC × GC-LRMS) data and applied to real high-volume air samples. Combination of the newly developed clean-up procedure and data treatment strategy enabled the prioritisation of over 600 compounds of interest in the particle phase (on GFF) and over 850 compounds in the gas phase (on PUF) out of over 25 000 chemical features detected in the raw dataset. Of these, 50 individual compounds were identified and confirmed with reference standards, 80 compounds were identified with a probable structure, and 774 compounds were assigned to various compound classes. In the dataset available here, 11 hitherto unknown halogenated compounds were detected. These unknown compounds were not yet listed in the available mass spectral libraries.
2021