scholarly journals Non-target and suspect characterisation of organic contaminants in ambient air – Part 1: Combining a novel sample clean-up method with comprehensive two-dimensional gas chromatography

2021 ◽  
Vol 21 (3) ◽  
pp. 1697-1716 ◽  
Author(s):  
Laura Röhler ◽  
Pernilla Bohlin-Nizzetto ◽  
Pawel Rostkowski ◽  
Roland Kallenborn ◽  
Martin Schlabach
Keyword(s):  
Gas Chromatography ◽  
Sulfuric Acid ◽  
Organic Contaminants ◽  
High Volume ◽  
Ambient Air ◽  
Two Dimensional ◽  
Particle Phase ◽  
Wide Scope ◽  
Air Samples ◽  
Concentrated Sulfuric Acid

Abstract. 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.

scholarly journals Non-target and suspect characterisation of organic contaminants in ambient air, Part I: Combining a novel sample clean-up method with comprehensive two-dimensional gas chromatography

2020 ◽  
Author(s):  
Laura Röhler ◽  
Pernilla Bohlin-Nizzetto ◽  
Pawel Rostkowski ◽  
Roland Kallenborn ◽  
Martin Schlabach
Keyword(s):  
Gas Chromatography ◽  
Trace Analysis ◽  
Organic Contaminants ◽  
High Volume ◽  
Ambient Air ◽  
Two Dimensional ◽  
Particle Phase ◽  
Wide Scope ◽  
Air Samples ◽  
Wide Range

Abstract. 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 of 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, and 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 to acid treatment. Recently developed suspect and non-target screening analytical strategies (SUS and NTS, respectively) are shown to be effective evaluation tools aiming at identifying a high number of compounds of emerging concern. These strategies, combining high sophisticated analytical technology with extensive data interpretation and statistics, are already widely accepted in environmental sciences for investigations of various environmental matrices but its 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 is using concentrated sulphuric acid. Analysis of raw air sample extracts, without clean-up, would generate an extensive contamination of the analytical system with especially 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 was 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 on 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 data set. 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 here available dataset, 11 hitherto unknown halogenated compounds were detected. These unknown compounds were not yet listed in the available mass spectral libraries.

scholarly journals Evaluation of atmospheric concentrations of dl-PCBs comparing to PCDD/F compounds in Istanbul, Turkey

2018 ◽  
Vol 21 (2) ◽  
pp. 113-123
Keyword(s):  
Gas Phase ◽  
Meteorological Factors ◽  
Winter Season ◽  
High Volume ◽  
Ambient Air ◽  
Particle Phase ◽  
Particulate Phase ◽  
Air Samples ◽  
Atmospheric Concentrations ◽  
Homolog Group

<p>In this study, the seasonal variation of atmospheric concentrations of PCDD/F and Dl-PCB and the effect of meteorological factors on concentration were investigated. Ambient air samples were collected monthly between May 2011 and October 2013 by using high volume samplers. Based on these samples, average PCDD/F and dl-PCB concentrations were obtained as 1482 fg/m3 and 4983 fg/m3 respectively. PCDD/F congeners did show seasonal variations. 58% share in total PCDD/Fs belongs to winter season while 4% to summer season. No significant seasonal change has been observed for dl-PCBs. 92% (1397 fg/m3) of PCDD/Fs were detected in particulate phase while 20% (926 fg/m3) of dl-PCBs were found in particulate phase. Strong negative correlations were obtained between all homolog groups and T, UV, SR. Correlation between five-chlorinated dl-PCBs, the most abandoned homolog group, with T, UV and SR generated positive meaningful correlation. No meaningful correlations were observed with other parameters. Correlations with particle phase were found to be more meaningful compared to gas phase for both PCDD/Fs and dl-PCBs.</p>

scholarly journals Polyfluoroalkyl compounds in the Canadian Arctic atmosphere

2011 ◽  
Vol 8 (4) ◽  
pp. 399 ◽  
Author(s):  
Lutz Ahrens ◽  
Mahiba Shoeib ◽  
Sabino Del Vento ◽  
Garry Codling ◽  
Crispin Halsall
Keyword(s):  
Gas Phase ◽  
Environmental Concern ◽  
Canadian Arctic ◽  
High Volume ◽  
Ambient Air ◽  
Coast Guard ◽  
The Arctic ◽  
Particle Phase ◽  
Method Performance ◽  
Arctic Atmosphere

Environmental contextPerfluoroalkyl compounds are of rising environmental concern because of their ubiquitous distribution in remote regions like the Arctic. The present study quantifies these contaminants in the gas and particle phases of the Canadian Arctic atmosphere. The results demonstrate the important role played by gas–particle partitioning in the transport and fate of perfluoroalkyl compounds in the atmosphere. AbstractPolyfluoroalkyl compounds (PFCs) were determined in high-volume air samples during a ship cruise onboard the Canadian Coast Guard Ship Amundsen crossing the Labrador Sea, Hudson Bay and the Beaufort Sea of the Canadian Arctic. Five PFC classes (i.e. perfluoroalkyl carboxylates (PFCAs), polyfluoroalkyl sulfonates (PFSAs), fluorotelomer alcohols (FTOHs), fluorinated sulfonamides (FOSAs), and sulfonamidoethanols (FOSEs)) were analysed separately in the gas phase collected on PUF/XAD-2 sandwiches and in the particle phase on glass-fibre filters (GFFs). The method performance of sampling, extraction and instrumental analysis were compared between two research groups. The FTOHs were the dominant PFCs in the gas phase (20–138 pg m–3), followed by the FOSEs (0.4–23 pg m–3) and FOSAs (0.5–4.7 pg m–3). The PFCAs could only be quantified in the particle phase with low levels (<0.04–0.18 pg m–3). In the particle phase, the dominant PFC class was the FOSEs (0.3–8.6 pg m–3). The particle-associated fraction followed the general trend of: FOSEs (~25 %) > FOSAs (~9 %) > FTOHs (~1 %). Significant positive correlation between ∑FOSA concentrations in the gas phase and ambient air temperature indicate that cold Arctic surfaces, such as the sea-ice snowpack and surface seawater could be influencing FOSAs in the atmosphere.

scholarly journals Assessment of of automated pressurized liquid extraction method followed by enzyme-linked immunosorbent assay for monitoring air-born dioxins

2021 ◽  
Author(s):  
Maryam Moradi
Keyword(s):  
High Resolution ◽  
Immunosorbent Assay ◽  
Ambient Air ◽  
Liquid Extraction ◽  
Pressurized Liquid Extraction ◽  
Enzyme Linked Immunosorbent Assay ◽  
Particle Phase ◽  
Air Samples ◽  
Recovery Test ◽  
Calibration Test

An automated procedure of sample preparation using pressurized liquid extraction (PLE) was developed for subsequent analysis by enzyme-linked immunosorbent assay (ELISA) for dioxins detection in ambient air samples collected from Burlington Ontario. Ambient air samples were collected from particle-phase using glass fibre filters (GFF) and from gas-phase using polyurethane foam from November 2014 to February 2015. The PLE extracts were cleaned up with acid silica followed by carbon mini-column. The average concentration of dioxins in particle phase was found to be 9.96±4.5 fgTEQ/m3 (n=10). This empirical finding is in agreement with high resolution gas chromatography –high resolution mass spectrometry (GC-MS) mean result of 10.04±2.9 fgTEQ/m3 (n=5). However, due to the limited sample size correlation between the two methods cannot be statistically established. The higher concentration of dioxins in Burlington, a city with heavy industry, was expected comparing the finding from previous study for downtown metropolitan Toronto (7.6 ± 2.0 fg BEQ/m3). Development of this method relied on calibration test, recovery test and Certified Reference Material (CRM) evaluation. Calibration test was successful in terms of developing standard curve with results within one standard deviation of the mean concentration of calibration standards. ELISA result on CRM was acceptable. Recovery test on extended toluene evaporation to half an hour or higher increased the recovery from 45% to an average of 82.4% for high concentrations and 89% for medium concentration of dioxins spike. The results of this study illustrate that PLE / ELISA can substitute for GC-HRMS as a cost effective screening tool to determine the dioxins concentration in ambient air.

scholarly journals Pesticides in the atmosphere: a comparison of gas-particle partitioning and particle size distribution of legacy and current-use pesticides

2016 ◽  
Vol 16 (3) ◽  
pp. 1531-1544 ◽  
Author(s):  
C. Degrendele ◽  
K. Okonski ◽  
L. Melymuk ◽  
L. Landlová ◽  
P. Kukučka ◽  
...  
Keyword(s):  
Czech Republic ◽  
Size Distribution ◽  
Fine Particles ◽  
Atmospheric Transport ◽  
High Volume ◽  
Rural Site ◽  
Particle Phase ◽  
Air Samples ◽  
Phase Size ◽  
Atmospheric Concentrations

Abstract. This study presents a comparison of seasonal variation, gas-particle partitioning, and particle-phase size distribution of organochlorine pesticides (OCPs) and current-use pesticides (CUPs) in air. Two years (2012/2013) of weekly air samples were collected at a background site in the Czech Republic using a high-volume air sampler. To study the particle-phase size distribution, air samples were also collected at an urban and rural site in the area of Brno, Czech Republic, using a cascade impactor separating atmospheric particulates according to six size fractions. Major differences were found in the atmospheric distribution of OCPs and CUPs. The atmospheric concentrations of CUPs were driven by agricultural activities while secondary sources such as volatilization from surfaces governed the atmospheric concentrations of OCPs. Moreover, clear differences were observed in gas-particle partitioning; CUP partitioning was influenced by adsorption onto mineral surfaces while OCPs were mainly partitioning to aerosols through absorption. A predictive method for estimating the gas-particle partitioning has been derived and is proposed for polar and non-polar pesticides. Finally, while OCPs and the majority of CUPs were largely found on fine particles, four CUPs (carbendazim, isoproturon, prochloraz, and terbuthylazine) had higher concentrations on coarse particles ( >  3.0 µm), which may be related to the pesticide application technique. This finding is particularly important and should be further investigated given that large particles result in lower risks from inhalation (regardless the toxicity of the pesticide) and lower potential for long-range atmospheric transport.

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