Please join us for the monthly BP4NTA meeting on July 22 at 12 pm US Eastern Time. Note that this is delayed a week from our normal schedule due to a speaker conflict! The Zoom link was sent out in an email to all BP4NTA members. Please email BP4NTA directly if you’d like access and have not received the email. Our featured speaker is Carrie McDonough, who will present on her work on PFAS using high-resolution mass spectrometry (HRMS), ion mobility spectrometry (IMS), and FluoroMatch
Abstract: We are continuously exposed to mixtures of per/polyfluoroalkyl substances (PFASs) via drinking water, diet, indoor dust, and commercial products. These mixtures include highly persistent perfluoroalkyl acids (PFAAs) and their precursors. There are thousands of PFAS precursors (i.e., PFASs that can be transformed via environmental and biological processes to form PFAAs) with a wide range of physical/chemical properties. However, few of these compounds are available as neat standards, which are necessary for unequivocal identification, quantification, and toxicity assays. Here, I will discuss our work using in vitro and in vivo techniques applied directly to complex PFAS mixtures containing known and unknown PFASs. These techniques enable us to identify, prioritize, and assess bioaccumulation potential of novel PFASs that are overlooked by traditional monitoring methods. I will also discuss recent results from our work using high-resolution mass spectrometry (HRMS), ion mobility spectrometry (IMS), and the open-source software FluoroMatch to characterize these PFAS mixtures and track compositional changes between external exposure and internal dose. These approaches were used to characterize serum, urine, kidney, and liver tissue from mice dosed via gavage with an electrochemically-fluorinated aqueous film-forming foam (AFFF). N-glucuronidated C4-C6 perfluoroalkyl sulfonamides (N-glu-FASAs) were identified in urine excreted throughout the dosing study, highlighting glucuronidation as a significant chain-length-dependent excretion pathway for FASAs and substituted FASAs after dealkylation. Chromatographic patterns and drift time spectra suggest that doubly glucuronidated FASAs were also formed and excreted in urine. Longer-chain (>C8) FASAs primarily accumulated in liver and kidney tissues and were not detected in post-depuration serum. Some examples of applications of these techniques to prioritize detection of novel PFASs in challenging trace-level samples and complex environmental mixtures will also be discussed.