The widespread use of aqueous film-forming foams (AFFFs) for hydrocarbon fuel firefighting has created an environmental legacy, as per- and polyfluoroalkyl substances (PFASs) continue to cause sustained groundwater plume development. We apply ultrahigh-resolution Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS) to identify compounds in AFFFs at the molecular level that can be used to guide the development of novel analytical approaches to catalogue PFASs associated with AFFF releases, and identify compounds not detected on lower resolution MS systems. Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) has become the method of choice for complex mixture analysis due to high mass-resolving power, high mass accuracy, and dynamic range (ratio of highest to lowest peak) sufficient to resolve and assign elemental compositions to tens of thousands of compounds simultaneously (e.g., petroleum and dissolved organic matter). The power of this technique lies in the ability to resolve compounds that differ in mass by roughly the mass of an electron while simultaneously detecting more than 80,000 compounds from the background hydrocarbon matrix. The requirement for ultrahigh resolving power in excess of that achievable by qToF-MS or Orbitrap MS is highlighted in Figure 1 (inset). A mass scale zoom inset at <i>m/z</i> 557 shows resolution of two unknown compounds that have the same nominal mass-to-charge ratio (<i>m/z</i> 557) but that differ in exact mass by 2.47 mDa, roughly the mass of five electrons. Importantly, these compounds would not be identified by any other mass spectral technique and thus be undetected. Our novel method will reveal PFAS “dark matter” composition with unparalleled mass accuracy and resolution, substantially improving AFFF fingerprinting and the assessment of environmental transport and transformation processes.

Ultrahigh-resolution Fourier-transform ion cyclotron resonance mass spectrometry for identification of per- and polyfluoroalkyl substances (PFASs)

2019 Fall National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.