Application of a novel prioritisation strategy using non-target screening for evaluation of temporal trends (1969-2017) of contaminants of emerging concern (CECs) in archived lynx muscle tissue samples

Most environmental monitoring studies of contaminants of emerging concern (CECs) focus on aquatic species and target specific classes of CECs. Even with wide-scope target screening methods, relevant CECs may be missed. In this study, non-target screening (NTS) was used for tentative identification of potential CECs in muscle tissue of the terrestrial top predator Eurasian lynx (Lynx lynx). Temporal trend analysis was applied as a prioritisation tool for archived samples, using univariate statistical tests (Mann-Kendall and Spearman rank). Pooled lynx muscle tissue collected from 1969 to 2017 was analysed with an eight-point time series using a previously validated screening workflow. Following peak detection, peak alignment, and blank subtraction, 12,941 features were considered for statistical analysis. Prioritisation by time-trend analysis detected 104 and 61 features with statistically significant increasing and decreasing trends, respectively. Following probable molecular formula assignment and elucidation with MetFrag, two compounds with increasing trends, and one with a decreasing trend, were tentatively identified. These results show that, despite low expected concentration levels and high matrix effects in terrestrial species, it is possible to prioritise CECs in archived lynx samples using NTS and univariate statistical approaches

What is in the fish? Collaborative trial in suspect and non-target screening of organic micropollutants using LC- and GC-HRMS

A collaborative trial involving 16 participants from nine European countries was conducted within the NORMAN network in efforts to harmonise suspect and non-target screening of environmental contaminants in whole fish samples of bream (Abramis brama). Participants were provided with freeze-dried, homogenised fish samples from a contaminated and a reference site, extracts (spiked and non-spiked) and reference sample preparation protocols for liquid chromatography (LC) and gas chromatography (GC) coupled to high resolution mass spectrometry (HRMS). Participants extracted fish samples using their in-house sample preparation method and/or the protocol provided. Participants correctly identified 9–69 % of spiked compounds using LC-HRMS and 20–60 % of spiked compounds using GC-HRMS. From the contaminated site, suspect screening with participants’ own suspect lists led to putative identification of on average ~145 and ~20 unique features per participant using LC-HRMS and GC-HRMS, respectively, while non-target screening identified on average ~42 and ~56 unique features per participant using LC-HRMS and GC-HRMS, respectively. Within the same sub-group of sample preparation method, only a few features were identified by at least two participants in suspect screening (16 features using LC-HRMS, 0 features using GC-HRMS) and non-target screening (0 features using LC-HRMS, 2 features using GCHRMS). The compounds identified had log octanol/water partition coefficient (KOW) values from − 9.9 to 16 and mass-to-charge ratios (m/z) of 68 to 761 (LC-HRMS and GC-HRMS). A significant linear trend was found between log KOW and m/z for the GC-HRMS data. Overall, these findings indicate that differences in screening results are mainly due to the data analysis workflows used by different participants. Further work is needed to harmonise the results obtained when applying suspect and non-target screening approaches to environmental biota samples

New extraction method prior to screening of organic micropollutants in various biota matrices using liquid chromatography coupled to high-resolution time-of-flight mass spectrometry

A new extraction method with limited clean-up requirements prior to screening various matrices for organic micropollutants using liquid chromatography-high resolution mass spectrometry (LC-HRMS) for analysis was developed. First, the performance of three extraction methods (QuEChERS with SPE clean-up, ultrasonication with SPE clean-up, extraction without SPE clean-up) was tested, optimized, and compared using > 200 contaminants of emerging concern (CECs) together covering a wide range of physicochemical properties applicable for suspect and non-target screening in biota. White-tailed sea eagle (Haliaeetus albicilla) muscle tissue was used in method development and optimization. The method without SPE clean-up was then applied to European perch (Perca fluviatilis) muscle, heart, and liver tissues. The optimization and application of the method demonstrated a wide applicable domain of the novel extraction method regarding species, tissues, and chemicals. For future applications, the suitability of the method for suspect and non-target screening was tested. Overall, our extraction method appears to be sufficiently simple and broad (relatively non-discriminant) for use prior to analysis of CECs in various biota

Wide-scope screening for contaminants of emerging concern in archived biota: Method development, suspect prioritisation, and non-target screening in a novel identification tool

Environmental monitoring of hazardous chemicals in wildlife conventionally uses target screening for selected contaminants, but relatively few contaminants are moni-tored and knowledge of potentially hazardous contaminants of emerging concern (CECs) in wildlife is lacking. In this thesis, a non-target screening (NTS) method com-bined with temporal trend analysis was developed and applied as a prioritisation tool for identification of CECs in top predators, using high-resolution mass spectrometry (HRMS). A multi-residue sample extraction and HRMS screening method was devel-oped and validated for various biota tissue types and species, to capture chemicals with a broad range of physiochemical properties (Paper I). Minimised sample pre-treatment and clean-up resulted in a non-specific extraction method for NTS in biota. A tool for creating suspect lists for screening of CECs in biota was developed based on an exten-sive database of chemicals (Paper II). Systematic ranking of chemicals based on rele-vant physicochemical properties was used to prioritize CECs relevant for biota and water. Finally, a NTS workflow was developed for prioritizing CECs in time series of archived biological tissue of top predators. The samples included time series of muscle tissue from white-tailed sea eagle (Haliaeetus albicilla) (1965-2017) and Eurasian lynx (Lynx lynx) (1969-2017) obtained from the environmental specimen bank (ESB) at the Swedish Museum of Natural History (SMNH). The prioritisation method was validated with an artificial time series using spiked matrix samples of increasing concentrations (Paper III). A total of 14 compounds (six of anthropogenic origin) with increasing time trends were tentatively identified in white-tailed sea eagle samples, while two com-pounds with increasing time trends and one compound with a decreasing time trend were tentatively identified in lynx samples (Paper IV). The tentatively identified com-pounds originated from different chemical categories (pharmaceuticals, personal care products, industrial chemicals, herbicides). These results showed that, despite the high matrix effect and low expected concentrations in terrestrial species (lynx), it was possi-ble to tentatively identify new CECs in wildlife. The novel prioritisation strategy and NTS workflow developed in this thesis can provide a useful tool for future identifica-tion of CECs in biota. The overall findings can help government agencies expand their monitoring programmes for identification of CECs in biota

Novel prioritisation strategies for evaluation of temporal trends in archived white-tailed sea eagle muscle tissue in non-target screening

Environmental monitoring studies based on target analysis capture only a small fraction of contaminants of emerging concern (CECs) and miss pollutants potentially harmful to wildlife. Environmental specimen banks, with their archived samples, provide opportunities to identify new CECs by temporal trend analysis and nontarget screening. In this study, archived white-tailed sea eagle (Haliaeetus albicilla) muscle tissue was analysed by non-targeted high-resolution mass spectrometry. Univariate statistical tests (Mann-Kendall and Spearman rank) for temporal trend analysis were applied as prioritisation methods. A workflow for non-target data was developed and validated using an artificial time series spiked at five levels with gradient concentrations of selected CECs (n = 243). Pooled eagle muscle tissues collected 1965-2017 were then investigated with an eightpoint time series using the validated screening workflow. Following peak detection, peak alignment, and blank subtraction, 14 409 features were considered for statistical analysis. Prioritisation by time-trend analysis detected 207 features with increasing trends. Following unequivocal molecular formula assignment to prioritised features and further elucidation with MetFrag and EU Massbank, 13 compounds were tentatively identified, of which four were of anthropogenic origin. These results show that it is possible to prioritise new CECs in archived biological samples using univariate statistical approaches

Screening of PFASs in groundwater andsurface water

Levels of 26 per- and polyfluoroalkyl substances (PFASs) were measured in 502 water samples originat-ing from Swedish groundwater, surface water, sewage treatment plant (STP) effluents and landfill leachates. In drinking water source areas, the average Σ26PFAS concentration was 8.4 ng L-1. The national drinking water guideline value of 90 ng L-1 for Σ7PFASs was exceeded in 2% of these samples. In water not used for drinking water, Σ26PFASs average concentration was 142 ng L-1. PFOS concentra-tions exceeded the Annual Average Environmental Quality Standard (AA-EQS) of the EU Water Frame-work Directive in 42% of the surface water samples. Among the different water categories, the landfill leachates had the highest average concentration of Σ26PFAS with 487 ng L-1, followed by surface water (average 112 ng L-1), groundwater (49 ng L-1), STP effluents (35 ng L-1) and background screening lakes (3.4 ng L-1). The composition profile of the PFASs differed between the types of waters showing an even distribution of ΣPFCAs, ΣPFSAs and ΣPFAS precursors in groundwater, whereas in all other water categories, ΣPFCAs were dominant. As FOSA, PFNA, PFDA, and 6:2 FTSA were frequently detected in drinking water source areas (constituted 20%, 7.3%, 5.9%, and 4.4% of the Σ26PFASs, respectively), it is reasonable to consider the inclusion of these in the Swedish drinking water guideline.Per- och polyfluoralkylerade ämnen (PFASs) är relativt nya organiska miljöförore-ningar som kännetecknas av att många av dem är långlivade, bioackumulerar och är toxiska. I den här studien analyserades 26 olika PFASs i 502 svenska vattenpro-ver av olika ursprung: grundvatten, ytvatten, avloppsvatten från reningsverk (STP) och lakvatten från deponier. Syftet med studien var att fastställa bakgrundskoncent-rationer av PFASs i den svenska vattenmiljön, identifiera PFAS källor samt jäm-föra PFAS-koncentrationer med riktvärden för bedömning av risker för ekosystem och människors hälsa. I källområden för dricksvatten var den genomsnittliga kon-centrationen av Σ26PFAS 8,4 ng L-1, med ett medianvärde på 0,6 ng L-1 (n = 172). Livsmedelsverkets rekommenderade gränsvärde för Σ7PFASs (PFPeA, PFHxA, PFHpA, PFOA, PFBS, PFHxS, PFOS) i dricksvatten (90 ng L-1) överskreds i 4 prover (2% av proverna för denna typ av vatten). I vatten som inte kom från käll-områden för dricksvatten var Σ26PFAS koncentrationerna högre med ett medel-värde på 142 ng L-1 och medianvärde på 5,4 ng L-1. Den höga medelkoncentration-en kan förklaras av att vissa prover hade extremt höga PFAS halter med ett topp-värde på 12 900 ng L-1. För substansen PFOS finns en miljökvalitetsnorm i EU:s ramdirektiv för vatten (vattendirektivet) som avser årsmedelvärde (AA-MKN). Denna norm överskreds i 42% av ytvattenproverna. Bland de olika vattenkategori-erna hade lakvatten den högsta genomsnittliga Σ26PFAS-koncentrationen (487 ng L-1, median 435 ng L-1, n = 10), följt av ytvatten (medel 112 ng L-1, median 4,1 ng L-1, n = 285), grundvatten (medel 49 ng L-1, median 0,4 ng L-1, n = 164), STP av-lopssvatten (medel 35 ng L-1, median 26 ng L-1, n = 13) och bakgrundsjöar (avläg-set belägna screening-sjöar, medel 3,4 ng L-1, median 1,4 ng L-1, n = 10). PFASs kan indelas i olika ämnesgrupper, t.ex. ΣPFCAs, ΣPFSAs och ΣPFAS-prekursorer. Sammansättningen av PFASs skilde sig mellan olika typer av vatten. Grundvattnen hade en jämn fördelning mellan dessa ämnesgrupper, medan i alla andra prover (ytvatten, bakgrundssjöar, STP avloppsvatten och lakvatten) dominerade ΣPFCAs. Eftersom FOSA, PFNA, PFDA och 6:2 FTSA ofta detekterades i vatten från käll-områden till dricksvatten (utgjorde 20%, 7,3%, 5,9% respektive 4,4% av Σ26PFASs) kan man överväga att inkludera dessa i det rekommenderade svenska gränsvärdet.Regeringsuppdrag: Screening av förekomsten av miljögifte

What is in the fish? Collaborative trial in suspect and non-target screening of organic micropollutants using LC- and GC-HRMS

A collaborative trial involving 16 participants from nine European countries was conducted within the NORMAN network in efforts to harmonise suspect and non-target screening of environmental contaminants in whole fish samples of bream (Abramis brama). Participants were provided with freeze-dried, homogenised fish samples from a contaminated and a reference site, extracts (spiked and non-spiked) and reference sample preparation protocols for liquid chromatography (LC) and gas chromatography (GC) coupled to high resolution mass spectrometry (HRMS). Participants extracted fish samples using their in-house sample preparation method and/or the protocol provided. Participants correctly identified 9-69% of spiked compounds using LC-HRMS and 20-60% of spiked compounds using GC-HRMS. From the contaminated site, suspect screening with participants’ own suspect lists led to putative identification of on average ∼145 and ∼20 unique features per participant using LC-HRMS and GC-HRMS, respectively, while non-target screening identified on average ∼42 and ∼56 unique features per participant using LC-HRMS and GC-HRMS, respectively. Within the same sub-group of sample preparation method, only a few features were identified by at least two participants in suspect screening (16 features using LC-HRMS, 0 features using GC-HRMS) and non-target screening (0 features using LC-HRMS, 2 features using GC-HRMS). The compounds identified had log octanol/water partition coefficient (KOW) values ranging from -9.9 to 16 and mass-to-charge ratio (m/z) of 68 to 761 (LC-HRMS and GC-HRMS). A significant linear trend was found between log KOW and m/z for the GC-HRMS data. Overall, these findings indicate that differences in screening results are mainly due to the data analysis workflows used by different participants. Further work is needed to harmonise the results obtained when applying suspect and non-target screening approaches to environmental biota samples