In support of the United Nations Environment Programme (UNEP) global monitoring plan under the St... more In support of the United Nations Environment Programme (UNEP) global monitoring plan under the Stockholm Convention contributing laboratories were offered to take part in a series of interlaboratory assessments on persistent organic pollutants (POPs). The results of two rounds of these assessments are reported. The target compounds were polychlorinated biphenyls, organochlorine pesticides, polybrominated diphenylethers, one polybrominated biphenyl and hexabromocyclododecane diastereomers. The matrices distributed were a test solution, fish, sediment, human milk, and air extracts. The number of participants in each round was well over 100, showing the interest of laboratories worldwide. The results showed that many laboratories still struggle to obtain acceptable standard deviations of around 25% for their determinations. In particular for organochlorine pesticides serious improvement in quality is required. Acceptable results were obtained for the air extracts and for the determination of polybrominated diphenylethers in various matrices.
Durable water repellent (DWR) impregnation is applied in textile finishing to impart water and, d... more Durable water repellent (DWR) impregnation is applied in textile finishing to impart water and, depending on impregnation chemicals, oil and stain resistance to textiles. Following the phase-out of the most effective and predominating DWR-technology based on long-chain perand polyfluoroalkyl substances (PFASs), the textile industry had to find suitable alternatives. This phase-out has resulted in a market where both fluorinated and non-fluorinated DWRs are available, dividable into three broad groups: short chain PFAS-based, silicone-based and hydrocarbonbased polymers. During our research in the SUPFES (Substitution of prioritised poly- and perfluorinated chemicals to eliminate diffuse sources) project, the alternative DWRs were assessed with regards to: (i)their structural properties and connected performance, (ii) loss and degradation processes resulting in diffuse environmental emissions, and (iii) hazard profile for selected emitted substances. We worked with DWR-chemistry and ...
Bi-ennial Global Interlaboratory Assessment on Persistent Organic Pollutants : Third Round 2016/2... more Bi-ennial Global Interlaboratory Assessment on Persistent Organic Pollutants : Third Round 2016/2017, Dioxin-like POPs and Perfluorinated Alkyl Substances
Since 2005, the United Nations Environment Programme (UNEP) has supported developing countries wi... more Since 2005, the United Nations Environment Programme (UNEP) has supported developing countries with capacity building, including on-site training courses and provision on laboratory materials and consumables, and analysis of samples from Africa, Asia-Pacific and Latin America and the Caribbean (GRULAC) in designated expert laboratories. In order to check the performance of laboratories analyzing persistent organic pollutants (POPs) and giving trust into chemical analytical results, four rounds of interlaboratory assessments (ILs) were organized between 2010 and 2019. These were open to all POPs laboratories. In total, 41 575 z-scores, as indicators of performance, were generated in these four ILs; of these, 8912 were from laboratories in countries supported by UNEP projects and 3923 were from expert laboratories; these together constitute 31% of the total. 69% of all z-scores came from laboratories not participating in the UNEP projects, especially from China, who recognized the importance of such exercises for quality control at an early stage. The results showed that POPs analytical capacity has increased over the years, but some gaps could not be closed especially not when LC-MS/MS equipment is essential such as for PFAS and congener-specific HBCD. Use of mass spectrometers provides better results than ECD instruments due to the broad spectrum of organochlorine pesticides to be analyzed under the Stockholm Convention. The main conclusion for all laboratories is that interlaboratory assessments provide important and objective snapshots of performance for the laboratories themselves and for external clients. The methods used in any interlaboratory testing should be the same as during routine analysis between such tests.
To assess the effects of weathering on per- and polyfluoroalkyl substances (PFASs) from durable w... more To assess the effects of weathering on per- and polyfluoroalkyl substances (PFASs) from durable water repellent (DWR) clothing, thirteen commercial textile samples were exposed to elevated ultra violet (UV) radiation, humidity, and temperature in an aging device for 300Â h, which mimics the lifespan of outdoor clothing. Before and after aging, the textile samples were extracted and analysed for the ionic PFASs (perfluoroalkyl acids (PFAAs), perfluorooctane sulfonamide (FOSA)) and volatile PFASs (fluorotelomer alcohols (FTOHs), acrylates (FTACs) and methacrylates (FTMACs)). Results showed that weathering can have an effect on PFASs used in DWR of outdoor clothing, both on the PFAS profile and on the measured concentrations. In most weathered samples the PFAA concentrations increased by 5- to more than 100-fold, while PFAAs not detected in the original textiles were detected in the weathered samples. DWR chemistries are based on side-chain fluorinated polymers. A possible explanation for the increase in concentration of the PFAAs is hydrolysis of the fluorotelomer based polymers (FTPs), or degradation of the FTOHs, which are used in the manufacturing of the FTPs. The concentrations of volatile PFASs also increased, by a factor up to 20. Suggested explanations are the degradation of the DWR polymers, making non-extractable fluorines extractable, or the transformation or degradation of unknown precursors. Further research is needed to unravel the details of these processes and to determine the transformation routes. This study shows that setting maximum tolerance limits only for a few individual PFASs is not sufficient to control these harmful substances in outdoor clothing.
Bi-ennial Global Interlaboratory Assessment on Persistent Organic Pollutants – Third Round 2016... more Bi-ennial Global Interlaboratory Assessment on Persistent Organic Pollutants – Third Round 2016/2017, Organochlorine Pesticides, PCBs and Brominated Flame Retardants
Tricresyl phosphate (TCP), and in particular its tri-ortho substituted isomer (o,o,o-TCP), has be... more Tricresyl phosphate (TCP), and in particular its tri-ortho substituted isomer (o,o,o-TCP), has been frequently used in aircraft engine oil. Bleed air, provided to the flight deck and cabin can contain traces of TCP. TCP can cause neurotoxic effects in humans. Regularly, airline pilots complain about loss of memory, headaches, dizziness, tunnel vision and other neurotoxic effects. The concentrations of TCP reported in flight deck air (max. ca. 50-100 ng m(-3) total TCP) do not exceed provisional toxicity thresholds. These thresholds, however, contain a very high uncertainty and need further underpinning. The many non-detects and relatively low TCP concentrations reported suggest that TCP on its own is not likely to be responsible for the reported health problems of pilots. Specific conditions in air planes and other toxic compounds present in bleed air, whether or not in combination with TCP, may be responsible for the reported neurotoxic syndromes. Sensitivity of individuals seems t...
ABSTRACT An increasing number of reports confirm the world-wide presence of the perfluoroalkyl su... more ABSTRACT An increasing number of reports confirm the world-wide presence of the perfluoroalkyl substances (PFASs). As a consequence, the demand for qualitative and quantitative environmental occurrence data requires accurate risk assessments. To improve the analytical quality of the determination of PFASs in food and environmental samples, a 4th international interlaboratory study (ILS) was conducted in 2011. A total of 31 partners participated, and, depending on the sample matrix, up to 29 data sets were submitted. The ILS focused on food samples, as it was organized by the PERFOOD consortium in collaboration with QUASIMEME. The results showed that the cumulative experience of the participants has improved their analytical quality over four international ILSs. Several sources of errors were identified and methods to avoid them are suggested.
In support of the United Nations Environment Programme (UNEP) global monitoring plan under the St... more In support of the United Nations Environment Programme (UNEP) global monitoring plan under the Stockholm Convention contributing laboratories were offered to take part in a series of interlaboratory assessments on persistent organic pollutants (POPs). The results of two rounds of these assessments are reported. The target compounds were polychlorinated biphenyls, organochlorine pesticides, polybrominated diphenylethers, one polybrominated biphenyl and hexabromocyclododecane diastereomers. The matrices distributed were a test solution, fish, sediment, human milk, and air extracts. The number of participants in each round was well over 100, showing the interest of laboratories worldwide. The results showed that many laboratories still struggle to obtain acceptable standard deviations of around 25% for their determinations. In particular for organochlorine pesticides serious improvement in quality is required. Acceptable results were obtained for the air extracts and for the determination of polybrominated diphenylethers in various matrices.
Durable water repellent (DWR) impregnation is applied in textile finishing to impart water and, d... more Durable water repellent (DWR) impregnation is applied in textile finishing to impart water and, depending on impregnation chemicals, oil and stain resistance to textiles. Following the phase-out of the most effective and predominating DWR-technology based on long-chain perand polyfluoroalkyl substances (PFASs), the textile industry had to find suitable alternatives. This phase-out has resulted in a market where both fluorinated and non-fluorinated DWRs are available, dividable into three broad groups: short chain PFAS-based, silicone-based and hydrocarbonbased polymers. During our research in the SUPFES (Substitution of prioritised poly- and perfluorinated chemicals to eliminate diffuse sources) project, the alternative DWRs were assessed with regards to: (i)their structural properties and connected performance, (ii) loss and degradation processes resulting in diffuse environmental emissions, and (iii) hazard profile for selected emitted substances. We worked with DWR-chemistry and ...
Bi-ennial Global Interlaboratory Assessment on Persistent Organic Pollutants : Third Round 2016/2... more Bi-ennial Global Interlaboratory Assessment on Persistent Organic Pollutants : Third Round 2016/2017, Dioxin-like POPs and Perfluorinated Alkyl Substances
Since 2005, the United Nations Environment Programme (UNEP) has supported developing countries wi... more Since 2005, the United Nations Environment Programme (UNEP) has supported developing countries with capacity building, including on-site training courses and provision on laboratory materials and consumables, and analysis of samples from Africa, Asia-Pacific and Latin America and the Caribbean (GRULAC) in designated expert laboratories. In order to check the performance of laboratories analyzing persistent organic pollutants (POPs) and giving trust into chemical analytical results, four rounds of interlaboratory assessments (ILs) were organized between 2010 and 2019. These were open to all POPs laboratories. In total, 41 575 z-scores, as indicators of performance, were generated in these four ILs; of these, 8912 were from laboratories in countries supported by UNEP projects and 3923 were from expert laboratories; these together constitute 31% of the total. 69% of all z-scores came from laboratories not participating in the UNEP projects, especially from China, who recognized the importance of such exercises for quality control at an early stage. The results showed that POPs analytical capacity has increased over the years, but some gaps could not be closed especially not when LC-MS/MS equipment is essential such as for PFAS and congener-specific HBCD. Use of mass spectrometers provides better results than ECD instruments due to the broad spectrum of organochlorine pesticides to be analyzed under the Stockholm Convention. The main conclusion for all laboratories is that interlaboratory assessments provide important and objective snapshots of performance for the laboratories themselves and for external clients. The methods used in any interlaboratory testing should be the same as during routine analysis between such tests.
To assess the effects of weathering on per- and polyfluoroalkyl substances (PFASs) from durable w... more To assess the effects of weathering on per- and polyfluoroalkyl substances (PFASs) from durable water repellent (DWR) clothing, thirteen commercial textile samples were exposed to elevated ultra violet (UV) radiation, humidity, and temperature in an aging device for 300Â h, which mimics the lifespan of outdoor clothing. Before and after aging, the textile samples were extracted and analysed for the ionic PFASs (perfluoroalkyl acids (PFAAs), perfluorooctane sulfonamide (FOSA)) and volatile PFASs (fluorotelomer alcohols (FTOHs), acrylates (FTACs) and methacrylates (FTMACs)). Results showed that weathering can have an effect on PFASs used in DWR of outdoor clothing, both on the PFAS profile and on the measured concentrations. In most weathered samples the PFAA concentrations increased by 5- to more than 100-fold, while PFAAs not detected in the original textiles were detected in the weathered samples. DWR chemistries are based on side-chain fluorinated polymers. A possible explanation for the increase in concentration of the PFAAs is hydrolysis of the fluorotelomer based polymers (FTPs), or degradation of the FTOHs, which are used in the manufacturing of the FTPs. The concentrations of volatile PFASs also increased, by a factor up to 20. Suggested explanations are the degradation of the DWR polymers, making non-extractable fluorines extractable, or the transformation or degradation of unknown precursors. Further research is needed to unravel the details of these processes and to determine the transformation routes. This study shows that setting maximum tolerance limits only for a few individual PFASs is not sufficient to control these harmful substances in outdoor clothing.
Bi-ennial Global Interlaboratory Assessment on Persistent Organic Pollutants – Third Round 2016... more Bi-ennial Global Interlaboratory Assessment on Persistent Organic Pollutants – Third Round 2016/2017, Organochlorine Pesticides, PCBs and Brominated Flame Retardants
Tricresyl phosphate (TCP), and in particular its tri-ortho substituted isomer (o,o,o-TCP), has be... more Tricresyl phosphate (TCP), and in particular its tri-ortho substituted isomer (o,o,o-TCP), has been frequently used in aircraft engine oil. Bleed air, provided to the flight deck and cabin can contain traces of TCP. TCP can cause neurotoxic effects in humans. Regularly, airline pilots complain about loss of memory, headaches, dizziness, tunnel vision and other neurotoxic effects. The concentrations of TCP reported in flight deck air (max. ca. 50-100 ng m(-3) total TCP) do not exceed provisional toxicity thresholds. These thresholds, however, contain a very high uncertainty and need further underpinning. The many non-detects and relatively low TCP concentrations reported suggest that TCP on its own is not likely to be responsible for the reported health problems of pilots. Specific conditions in air planes and other toxic compounds present in bleed air, whether or not in combination with TCP, may be responsible for the reported neurotoxic syndromes. Sensitivity of individuals seems t...
ABSTRACT An increasing number of reports confirm the world-wide presence of the perfluoroalkyl su... more ABSTRACT An increasing number of reports confirm the world-wide presence of the perfluoroalkyl substances (PFASs). As a consequence, the demand for qualitative and quantitative environmental occurrence data requires accurate risk assessments. To improve the analytical quality of the determination of PFASs in food and environmental samples, a 4th international interlaboratory study (ILS) was conducted in 2011. A total of 31 partners participated, and, depending on the sample matrix, up to 29 data sets were submitted. The ILS focused on food samples, as it was organized by the PERFOOD consortium in collaboration with QUASIMEME. The results showed that the cumulative experience of the participants has improved their analytical quality over four international ILSs. Several sources of errors were identified and methods to avoid them are suggested.
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