Rationale
The ability to perform absolute quantitation and non‐targeted analysis on a single mass spectrometry instrument would be advantageous to many researchers studying per‐ and polyfluoroalkyl substances (PFAS). High‐resolution accurate mass (HRAM) instrumentation (typically deployed for non‐targeted work) carries several advantages over traditional triple quadrupole workflows when performing absolute quantitation. Processing this data using a vendor‐neutral software would promote collaboration for these environmental studies.
Methods
LC‐MS (Orbitrap Exploris 240) was used for absolute quantitation of 45 PFAS using precursor (MS1) peak areas for quantitation, whereas isotope pattern matching and fragmentation (MS2) pattern matching were used for qualitative identification. In addition, a fluorinated chromatographic column achieved superior separation compared to the typical C18 columns typically used in PFAS analyses. This method was validated across eight different chemical classes using recommended guidelines found in EPA Method 537.1 and Skyline data processing software.
Results
The validated limits of all 45 compounds, as well as metrics or accuracy and reproducibility, are reported. Most compounds achieved limits of quantitation in the range of 2‐50 ng/L. Four newly released Chemours‐specific compounds (PEPA, PFO3OA, PFO4DA, and PFO5DoA) were also validated. Aspects of data analysis specific to high resolving power absolute quantitation are reviewed as are the details of processing these data via Skyline.
Conclusions
This method shows the feasibility of performing reproducible absolute quantitation of PFAS on an HRAM platform and does so using an open‐source vendor‐neutral data processing software to facilitate sharing of data across labs and institutions.
Per- and polyfluoroalkyl substances (PFAS) are persistent, bioaccumulative chemicals that can be toxic at very low levels. Many of these compounds have unusual chemical properties that can have a large...
Tilletia caries infection of wheat (Triticum aestivum) has become an increasing problem in organic wheat agriculture throughout the world. Little is known about how this pathogen alters host metabolism to ensure a successful infection. We investigated how T. caries allocates resources from wheat for its growth over the life cycle of the pathogen. An untargeted metabolomics approach that combined gas chromatography time-of-flight mass spectrometry and ultraperformance liquid chromatography tandem mass spectrometry platforms was used to determine which primary or specialized metabolite pathways are targeted and altered during T. caries infection. We found that T. caries does not dramatically alter the global metabolome of wheat but instead alters key metabolites for its own nutrient uptake and to antagonize host defenses by reducing wheat’s sweet immunity response and other related pathways. Our results highlight metabolic characteristics needed for selecting wheat varieties that are resistant to T. caries infection for organic agriculture. In addition, several wheat metabolites were identified that could be used in developing a diagnostic tool for early detection of T. caries infection.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.