Aqueous film-forming foams (AFFFs) are widely used to
extinguish
liquid fires due to their film-forming properties. AFFF formulation
historically contains per- and polyfluoroalkyl substances (PFASs)
that can be very persistent and pose a health risk to biota and humans.
Detailed analysis of the chemical composition of AFFFs can provide
a better understanding on the potential environmental impact of the
ingredients. In this study, a novel workflow combining target analysis,
nontarget screening analysis (NTA), total fluorine (TF) analysis,
and inorganic fluoride (IF) analysis was applied to disclose the chemical
composition of 24 foams intended for liquid fires. Foams marketed
as containing PFASs as well as fluorine-free foams were included.
By comparing the sum of targeted PFASs and total organofluorine concentrations,
a mass balance of known and unknown organofluorine could be calculated.
Known organofluorine accounted for <1% in most fluorine-containing
AFFFs, and it was confirmed that the foams marketed as fluorine-free
did not contain measurable amounts of organofluorine substances. Five
fluorinated substances were tentatively identified, and non-fluorinated
zwitterionic betaine compounds, which are considered to be replacement
substances for PFASs, were tentatively identified in the organofluorine-free
foams.
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.
To facilitate the study of potential harmful compounds sorbed to microplastics, an effect-directed analysis using the DR CALUX ® 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.
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