Inter-laboratory mass spectrometry dataset based on passive sampling of drinking water for non-target analysis

Non-target analysis (NTA) employing high-resolution mass spectrometry is a commonly applied approach for the detection of novel chemicals of emerging concern in complex environmental samples. NTA typically results in large and information-rich datasets that require computer aided (ideally automated) strategies for their processing and interpretation. Such strategies do however raise the challenge of reproducibility between and within different processing workflows. An effective strategy to mitigate such problems is the implementation of inter-laboratory studies (ILS) with the aim to evaluate different workflows and agree on harmonized/standardized quality control procedures. Here we present the data generated during such an ILS. This study was organized through the Norman Network and included 21 participants from 11 countries. A set of samples based on the passive sampling of drinking water pre and post treatment was shipped to all the participating laboratories for analysis, using one pre-defined method and one locally (i.e. in-house) developed method. The data generated represents a valuable resource (i.e. benchmark) for future developments of algorithms and workflows for NTA experiments

Optimizing nontarget workflows for identification of organic contaminants in various matrices

Since year 2000, production of chemicals around the world has more than doubled. Chemicals are used in many and diverse applications in our everyday life and even if their properties are useful, some can have a negative impact on environment and humans. It is thus important to monitor these chemicals to better understand their impact on the environment and human health. In this thesis, nontarget analysis (NTA) was used to detect and identify organic compounds in various environmental and health relevant matrices such as fish, indoor dust, aqueous film-forming foams (AFFFs) and fire emissions. The aim was to optimize the workflow by extracting relevant chemical information from the analysed matrix and mitigate bias in reported results. Tests were thus performed to optimize sample preparation for fish and dust samples as well as processing data from high-resolution mass spectrometry analysis of dust, AFFFs and fire emissions. Statistical analysis such as analysis of variance (ANOVA) with the help of hierarchical cluster analysis (HCA) enabled the detection of outliers in dust, AFFFs, and gas and soot from fire emissions. Mass defect (MD) plot analysis further enabled the detection of various relevant compounds according to their functional groups and structural properties. The nontarget analysis workflow was supported by target and suspect screening analysis to confirm the efficiency of the optimized overall workflow. Various classes of compounds could be detected and tentatively identified such as flame retardants, liquid crystal monomers or bisphenols in dust samples, organofluorine and fluorine-free surfactants in AFFFs, and flame retardants and hydrocarbons in gas and soot samples .Quality controls were also performed to assess the performance of the optimized workflow

Identification of organic contaminants in indoor dust by comprehensive target, suspect and nontarget screening analysis

I norra Europa tillbringar vi mer än 90% av vår tid i olika inomhusmiljöer och kemikalier som avges från byggmaterial och produkter kan vara viktiga exponeringsvägar för människor som vistas i dessa miljöer. Många industriella kemikalier används som tillsatser och dessa är vanligtvis inte kemiskt bundna till materialet och kan därför avges i inomhusmiljön över tid eller under användning. Inomhusdamm har påvisats vara en bra indikator för polära och icke-polära organiska föroreningar i inomhusmiljön. I denna studie insamlades damm på ytor från olika inomhusmiljöer såsom bostäder, kontor, förskolor, tryckeri, möbelaffär och elektronikbutik. De insamlade inomhusdammproverna extraherades med ultraljudsextraktion utan provupprening för att minimera förlust av ämnen under provberedningsproceduren. Extraktet delades upp och analyserades med både vätskekromatograf kopplad till högupplösande masspektrometer (LC-HRMS) och gaskromatograf kopplad till HRMS (GC-HRMS). En omfattande analystrategi med riktad analys av ett antal förvalda ämnen, en så kallad suspect screening och förutsättningslös analys genomfördes, vilket resulterade i detektion av mer än 260 ämnen i inomhusdamm. Dessa inkluderar kemikalier som används som flamskyddsmedel, mjukgörare, flytkristallmonomerer (liquid crystal monomers, LCMs), aktiva ingredienser i läkemedel och personvårdsprodukter, desinfektionsmedel, färgämnen, högfluorerade ämnen, UV-stabilisatorer, bekämpningsmedel, doftämnen och växtmetaboliter. Potentiella riskerna som är förknippade med inomhusdammsexponering av många av dessa kemikalierna samt kombinationseffekter är inte välkända. Majoriteten av den kemiska sammansättningen i inomhusdammproverna är fortfaranade inte klarlagt och många häsloskadliga föroreningar som kan finnas i proven kan fortfarande inte identifieras. Studier rekommenderas för att identifera fler ämnen genom förbättrade analysmetoder eller förfina identifieringsflöden genom att till exempel utöka så kallade suspect list med fler högkvalitativa HRMS-spektra av ämnen som ännu inte finns tillgängliga

Extended characterization of the indoor dust chemical composition by retrospective suspect and non-target analysis of high resolution mass spectrometric data

With the recent improvements in high-resolution mass spectrometry (HRMS), retrospective chemical analysis has been increasingly used in environmental sciences. This enables new insights into the chemical content of previously analysed samples with new data analysis methods or new information about emerging contaminants. This study aimed to conduct an in-depth investigation into the chemical content of various indoor dust samples using retrospective analysis. The samples were previously extracted using liquid-solid extraction without clean-up to increase the chemical coverage and thereafter analysed both using liquid chromatography (positive and negative ionisations) and gas chromatography coupled with high-resolution mass spectrometry. A retrospective data processing workflow was conducted in this new study by using both suspect screening analysis and non-target analysis. Among 30 dust samples from four different indoor settings, 298 compounds were tentatively identified with an identification confidence level of ≥ 3. The discussion was conducted on both individual compounds as well as their chemical compound groups and functional uses. Main detected chemical groups were plant natural products (n = 57), personal care products (n = 44), pharmaceuticals (n = 44), food additives (n = 43), plasticisers (n = 43), flame retardants (n = 43), colourants (n = 42) and pesticides (n = 31). Although some detected compounds were already reported for the same samples in our previous study, this retrospective analysis enabled the tentative identification of compounds such as polyethylene glycols, per- and polyfluoroalkyl substances, pesticides, benzotriazoles, benzothiazoles, fragrances, colourants and UV stabilizers. This study showed the usefulness of retrospective analysis on indoor dust samples to further characterise the chemical content, which can help to better estimate the exposure risks of organic contaminants to humans in the indoor environment

Comparison of extraction and clean-up methods for comprehensive screening of organic micropollutants in fish using gas chromatography coupled to high-resolution mass spectrometry

Monitoring the vast number of micropollutants in the environment by using comprehensive chemical screening is a major analytical challenge. The aim of this study was to evaluate a comprehensive analysis method for screening purposes of fish muscle samples by comparing sample preparation methods for a broad range of mid-to non-polar contaminants. Five extraction and three clean-up methods were evaluated for the analysis of 60 compounds with a log Kow range between 0.8 and 8.3 in fish. Both fresh and freeze-dried muscle tissue and extraction sodium sulphate blanks were included to assess recoveries and matrix effects. The performance of the different methods was evaluated using both comprehensive target and nontarget analysis using high resolution mass spectrometry (HRMS). The results showed that open-column and ultrasonication extractions (recoveries mostly between 20 and 160 %) resulted in higher recoveries than accelerated solvent extraction (ASE) (recoveries mostly between 20 and 80 %) and bead mixer homogenization extractions (recoveries between 0 and 50 % for the whole Kow range). Multilayer silica was the clean-up method resulting in the lowest matrix effects and highest recoveries, however some compounds (mostly pesticides) were denatured under the acidic conditions used. The convenient and time efficient ultrasonication extraction followed by deactivated silica clean-up proved to be promising for both target and nontarget approaches. The large difference in recoveries and number of detected peaks using target and nontarget approaches between fresh and freeze-dried fish seen for all methods calls for careful consideration, and further studies are needed to improve performance for screening of mid-to non-polar compounds in freeze-dried fish

Screening of “spice” herbal mixtures: From high-field to low-field proton NMR

International audienc

Thermal degradation of pesticide active substances: Prioritisation list

This study aims at estimating which pesticide active substances (ASs) are the best candidates to study potential further degradation of the AS above 120°C. To achieve this, a prioritisation list was built following five consecutive criteria. This first includes substances that are anthropogenic, have a carbon backbone structure, are authorized in the European Union, and have a defined maximum residue limit (MRL). Then, substances were selected according to their physicochemical and structural properties, MRL in main food commodities, standard price and degradation in hydrolysis studies below 120°C. The results showed that out of the initial 1 478 substances reported in the European pesticide database, 24 ASs were selected as the best candidates to test the assumption of degradation above 120°C. This prioritisation list could be useful for future research studies to build their own list and save time in selecting suitable candidates according to their criteria

Effect-Directed Analysis of Ah Receptor-Mediated Potencies in Microplastics Deployed in a Remote Tropical Marine Environment

To facilitate the study of potential harmful compounds sorbed to microplastics, an effect-directed analysis using the DR CALUX (R) assay as screening tool for Aryl hydrocarbon receptor (AhR)-active compounds in extracts of marine deployed microplastics and chemical analysis of hydrophobic organic compounds (HOCs) was conducted. Pellets of three plastic polymers [low-density polyethylene (LDPE), high-density polyethylene (HDPE) and high-impact polystyrene (HIPS)] were deployed at Heron Island in the Great Barrier Reef, Australia, for up to 8 months. Detected AhR-mediated potencies (bio-TEQs) of extracted plastic pellets ranged from 15 to 100 pg/g. Contributions of target HOCs to the overall bioactivities were negligible. To identify the major contributors, remaining plastic pellets were used for fractionation with a gas chromatography (GC) fractionation platform featuring parallel mass spectrometric (MS) detection. The bioassay analysis showed two bioactive fractions of each polymer with bio-TEQs ranging from 5.7 to 14 pg/g. High resolution MS was used in order to identify bioactive compounds in the fractions. No AhR agonists could be identified in fractions of HDPE or LDPE. Via a multivariate statistical approach the polystyrene (PS) trimer 1e-Phenyl-4e-(1- phenylethyl)-tetralin was identified in fractions of HIPS and in fractions of the blank polymer of HIPS

Towards comprehensive identification of pesticide degradation products following thermal processing below and above 120 °C: A review

International audienceCharacterising pesticide residues from a qualitative and quantitative point of view is key to both risk assessment in the framework of pesticide approval and risk management. In the European Union (EU), these concerns are addressed during the evaluation of active substances at the European level prior to marketing authorisation. In the framework of this review, we will focus on one specific item of the residue section, namely the effect of process (industrial or domestic transformation of the raw commodities) on the nature of the residue in food. A limited number of hydrolysis conditions defined by three parameters (temperature, pH and time) are set to be “representative of the most widely used industrial and domestic food processing technologies”. These hydrolysis conditions, however, do not cover processes at temperatures higher than 120 °C, such as cooking with a conventional oven or in a pan, frying or using a microwave oven

Organic contaminants formed during fire extinguishing using different firefighting methods assessed by nontarget analysis

During a fire event, potentially hazardous chemicals are formed from the combustion of burning materials and are released to the surrounding environment, both via gas and soot particles. The aim of this investigation was to study if firefighting techniques influence the emission of chemicals in gas phase and soot particles. Five full-scale fire tests were extinguished using four different firefighting techniques. A nontarget chemical analysis approach showed that important contaminants in gas and soot separating the different tests were brominated flame retardants (BFRs), organophosphate flame retardants (OPFR), polycyclic aromatic hydrocarbons (PAHs) and linear hydrocarbons. Reproducibility was evaluated by a field replicate test and it was determined that the temperature curve during the event had a bigger impact on the released chemicals than the firefighting technique used. However, despite fire intensity being a confounding factor, multivariate statistics concluded that water mist with additive resulted in less BFR emissions compared to foam extinguishing. The analysis also showed that the conventional spray nozzle method released more PAHs compared with the water mist method. The comprehensive chemical analysis of gas and soot released during fire events was able to show that different firefighting techniques influenced the release of chemicals.