November 15, 2023 12:00pm - 1:00pm EPA's Mark Strynar, PhD, to speak on campus Nov. 15 on "Investigations of PFAS Around Industrial Manufacturing Sites"

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ABSTRACT

Per- and polyfluoroalkyl substances (PFAS) have gone from environmental obscurity two decades ago, to one of the most common representations of environmental contaminants at present. A long history of production, use, disposal, and emission from a global network of sources is evident in the environmental literature. Compounding the issue of environmental contamination is the cooccurrence of historical PFAS, with contemporary produced/emitted PFAS in collected samples. Targeted analysis of environmental samples with low resolution MS/MS is the method of choice for known contaminants. Unfortunately, only a select species (<100) of 1000s of PFAS are sufficiently known and amenable to targeted analysis. A series of industrial site investigations within and outside of the United States at active production facilities have provided new insights into current and future PFAS. Therefore, high-resolution mass spectrometry and non-targeted analysis (NTA) methods are more appropriate for novel compound discovery. Parsing and annotation of 100s to 1000s of mass spectral features from these investigations is time consuming and quite often leads to PFAS of unknown or suspect identification. Application of mass spectral feature alignment (m/z, retention time abundance) coupled with application of the aftermarket FluoroMatch software packet has helped to make recent advancement in many of these site investigations. Such MS application can simultaneously rule out legacy PFAS not requiring further exploration (e.g. M-H, CO2 loss, gas phase dimers) while identifying features demanding further scrutiny (e.g. CF2 Kendrick mass defect homologous series). Water samples collected near and distant from production sites aid in source apportionment. This talk will focus on the procedures used to identify suspected and novel PFAS at these facilities while offering insight into future PFAS for consideration on a broader scale. Contemporary production and use facility emissions are a strong indication of future environmental contaminants. Even in unknown compound identification, having knowledge of homologous series grouping (e.g. CF2, CF2O, CF2CH2, others) and characteristic negative mass defect alone help in sifting through scores of data needing more intensive analyst follow-up. Examples of unknown compounds within a known homologous series, and well as novel one-off and homologs will be presented. The natural progression of methods from novel compound discovery to robust targeted methods hinges on this critical identification first step and is often at industrial production and use facilities.

PRESENTER BIO

Dr. Strynar is a Physical Scientist in the Office of Research and Development of the U.S, Environmental Protection Agency since 2002. His research interests include the use of high resolution mass spectrometry (HRMS) to investigate the fate and transport of per and poly fluorinated compounds (PFAS) and other xenobiotic compounds in biological and environmental media. Additionally, he is interested in novel compound discovery in environmental media and development of analytical methods for unique biomarkers of exposure to chemicals that are useful for dosed animal or human epidemiological studies.