Alternative Ionization Techniques for Analysis of Perfluoroalkyl Substances (PFAS) at Low Levels

Presented on April 28, 2022, by Sarah Dowd - Waters Corporation - at the 2022 Emerging Contaminants in the Environment Conference (ECEC22)

Perfluoroalkyl substances (PFAS) are a group of compounds commonly used in industrial and consumer goods. As a result of their widespread use, these compounds have been found in all types of environmental samples. Current guidelines focus on PFAS contamination in water and require parts per trillion (ppt) detection. Liquid chromatography with mass spectrometry (LC-MS/MS) using electrospray ionization (ESI) is widely accepted as the standard technique for PFAS analysis in environmental samples. The growing concern for exposure to these persistent chemicals dictates that analytical testing push for even lower detection limits and methodology as new PFAS compounds are added to regulations. A strategy to reach lower detection limits would be to improve the ionization efficiency as compounds are introduced to the MS. For the legacy and emerging PFAS compounds, we have found that an alternate ionization, UniSpray, produced a boost in signal and an increased response in the MS. As new compounds are added to regulations, the standard LC-MS/MS with ESI will not be suitable. Neutral PFAS such as volatile fluorotelomer alcohols are analyzed with gas chromatography (GC)-MS and we have found that using an atmospheric pressure source coupled with GC allows us to detect these compounds at ppt levels.

Download slides: http://hdl.handle.net/2142/114121