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 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 High-resolution computed tomography findings in eight patients with hantavirus pulmonary syndrome

2017 ◽  
Vol 50 (3) ◽  
pp. 148-153 ◽  
Author(s):  
Diego de Lacerda Barbosa ◽  
Bruno Hochhegger ◽  
Arthur Soares Souza Jr. ◽  
Gláucia Zanetti ◽  
Dante Luiz Escuissato ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Pleural Effusion ◽  
High Resolution ◽  
Pulmonary Edema ◽  
Immunosorbent Assay ◽  
Serological Test ◽  
Hantavirus Pulmonary Syndrome ◽  
Enzyme Linked Immunosorbent Assay ◽  
High Resolution Computed Tomography ◽  
Histopathologic Findings

Abstract Objective: The purpose of this study was to describe the high-resolution computed tomography (HRCT) findings in patients with hantavirus pulmonary syndrome (HPS). Materials and Methods: We retrospectively reviewed HRCT findings from eight cases of HPS. All patients were men, aged 19-70 (mean, 41.7) years. Diagnoses were established by serological test (enzyme-linked immunosorbent assay) in all patients. Two chest radiologists analyzed the images and reached decisions by consensus. Results: The predominant HRCT findings were ground-glass opacities (GGOs) and smooth inter- and intralobular septal thickening, found in all eight cases; however, the crazy-paving pattern was found in only three cases. Pleural effusion and peribronchovascular thickening were observed in five patients. The abnormalities were bilateral in all patients. Conclusion: The predominant HRCT findings in patients with HPS were GGOs and smooth inter- and intralobular septal thickening, which probably correlate with the histopathologic findings of pulmonary edema.

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>

Electron Microscopic Characterization and Quantitation of Air Borne Particulate Matter with Special Emphasis on Asbestos

1972 ◽  
Vol 30 ◽  
pp. 356-357
Author(s):  
Peter K. Mueller ◽  
Glenn R. Smith ◽  
Leslie M Carpenter ◽  
Ronald L. Stanley
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Ambient Air ◽  
Quality Standard ◽  
Primary Objective ◽  
Cellulose Ester ◽  
Main Concept ◽  
Electron Microscopic ◽  
Air Samples ◽  
Diffraction Patterns

At the present time the primary objective of the electron microscopy group of the Air and Industrial Hygiene Laboratory is the development of a method suitable for use in establishing an air quality standard for asbestos in ambient air and for use in its surveillance. The main concept and thrust of our approach for the development of this method is to obtain a true picture of fiber occurrence as a function of particle size and asbestos type utilizing light and electron microscopy.We have now available an electron micrographic atlas of all asbestos types including selected area diffraction patterns and examples of fibers isolated from air samples. Several alternative approaches for measuring asbestos in ambient air have been developed and/or evaluated. Our experiences in this regard will be described. The most promising method involves: 1) taking air samples on cellulose ester membrane filters with a nominal pore size of 0.8 micron; 2) ashing in a low temperature oxygen plasma for several hours;

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