Simultaneous Quantitation of Ultrashort-, Short- and Long-chain PFAS in Different Water Matrices

Per- and Polyfluoroalkyl Substances (PFAS) in the Environment
Oral Presentation

Presented by K. Adams
Prepared by C. Butt1, H. Lee2, S. Roberts3, S. Lodge4, C. Young5, T. VandenBoer5, R. Ye5
1 - SCIEX, 500 Old Connecticut Path, Framingham, MA, 01701, United States
2 - SCIEX, 71 Four Valley Dr, Concord, ON, L4K 4V8, Canada
3 - SCIEX, 6390 Joyce Dr # 100, Golden, CO, 80403, United States
4 - Phenomenex, 411 Madrid Ave, Torrance, CA, 90501, United States
5 - Chemistry Department, York University, 4700 Keele Street, Toronto, ON, M3J 1P3, Canada


Contact Information: [email protected]; 774-375-0524

ABSTRACT

Ultrashort-chain perfluoroalkyl acids (PFAAs) (<4 carbons) have historically been overlooked due to their presumed low toxicity and bioaccumulation potential, as well as their relative analytical challenges due to poor retention on traditional reverse-phase LC columns and high background levels. However, studies have reported their global distribution in a variety of environmental matrices, frequently at levels higher than longer-chain PFAS. In this this, an LC-MS/MS method is developed based on mixed-mode chromatography which enables simultaneous analysis of ultrashort, short and long-chain (C1–C14) PFAAs at sub-to-low ng/L concentrations in different water matrices.
Tap water, surface water and rainwater were collected from different regions in Ontario, Canada. Each water sample was diluted with methanol/water and spiked with internal standards for LC-MS/MS analysis. Sample extracts were chromatographically separated using a mixed-mode column that provided both C18- and ionic-based retention. Extensive chromatographic method development ensured good analyte retention from the void volume with TFA eluting first at ~5 minutes.

Excellent quantitative performance was demonstrated based on the calibration linearity (r2 >0.99), accuracy and precision of solvent standards LOQs. The mass spectrometer sensitivity enabled a simple dilution approach at LOQs ranging from 0.1 to 10 ng/L for most of the target analytes. However, both TFA and PFBA required a higher LOQ of 50 ng/L to compensate for their background contamination. Tap water spikes prepared at varying concentrations demonstrated excellent recoveries (±30% of the nominal spiked value) and precision (<20%). Application of the method to drinking water, lake water and rainwater revealed the detection of some ultrashort-, short- and long-chain PFAAs.