Presenter: Cory Scanlan, Waters Corporation, Mass Spectrometry Specialist 

Per- and polyfluoroalkyl substances (PFAS) have been identified as a class of contaminants of high concern due to their negative health effects and widespread presence in the environment. One potential source of PFAS is leachate from industrial and municipal landfills. Testing for PFAS in landfill leachate typically relies on targeted analysis methods that are limited to a list of 40 target PFAS. 

Non-targeted analysis (NTA) with high-resolution mass spectrometry (HRMS) is a promising technique for the discovery and identification of broader list of PFAS. Here, HRMS was coupled with liquid chromatography and ion mobility separation (IMS) on the SELECT SERIES™ Cyclic™ IMS mass spectrometer (Waters Corporation) to improve the number of detected features in the complex landfill leachates. 

Branched isomers are not well characterized and not typically separated chromatographically. The SELECT SERIES Cyclic IMS allows for scalable IMS separations with increased resolving power using multiple passes, when applied led to structural separation and identification of similar branched isomers. 

For discovery of PFAS not in the suspect library, IMS takes advantage of the lower CCS values for these compounds. Observed drift time and m/z were used to reveal polyhalogenated species that were in the leachates even at low intensity levels.