The chemical methods for removal of the per fulorinated compounds are of significant research interest. In this work, for the first time NMR was used for the assessement of PFOA degradation mechanism by sulfate radicals. The work was realized primarly thanks to laboratory equipement of Dr. James G. Longstaffe (University of Guelph, Canada) and his outstanding NMR knowledge.
Title: Benchtop 19F NMR spectroscopy as a practical tool for testing of remedial technologies for the degradation of perfluorooctanoic acid, a persistent organic pollutant
Authors: Kavi Heerah; Stanislaw Waclawek; Julie Konzuk; James G. Longstaffe
Abstract: The development of effective remedial technologies for the destruction of environmental pollutants requires the ability to clearly monitor degradation processes. Nuclear magnetic resonance (NMR) spectroscopy is a powerful tool for understanding reaction progress; however, practical considerations often restrict the application of NMR spectroscopy as a tool to better understand the degradation of environmental pollutants. Chief among these restrictions is the limited access smaller environmental research labs and remediation companies have to suitable NMR facilities. Benchtop NMR spectroscopy is a low‐cost and user‐friendly approach to acquire much of the same information as conventional nuclear magnetic resonance (NMR) spectroscopy, albeit with reduced sensitivity and resolution. This paper explores the practical application of benchtop NMR spectroscopy to understand the degradation of perfluorooctanoic acid using sodium persulfate, a common reagent for the destruction of groundwater contaminants. It is found that Benchtop 19F NMR spectroscopy is able to monitor the complete degradation of perfluorooctanoic acid into fluoride; however, the observation of intermediate degradation products formed, which can be observed using a conventional NMR spectrometer, cannot be readily distinguished from the parent compound when measurements are performed using the benchtop instrument. Under certain reaction conditions, the formation of fluorinated structures that are resistant to further degradation is readily observed. Overall, it is shown that benchtop 19F NMR spectroscopy has potential as a quick and reliable tool to assist in the development of remedial technologies for the degradation of fluorinated contaminants.
Available at: https://onlinelibrary.wiley.com/doi/full/10.1002/mrc.5005