Total Organofluorine (TOF) Analysis by Combustion Ion Chromatography – A New Tool for Monitoring PFAS Impacts

Polyfluoroalkyl Substances (PFAS) in the Environment
Oral Presentation

Prepared by H. Lord
Bureau Veritas, 6740 Campobello Road, Mississauga, Ontario, L5N 2L8, Canada


Contact Information: [email protected]; 19058175711

ABSTRACT

Total organofluorine (or ‘organic fluorine’) analysis, refers to the measurement of fluorine that originates from any substance where fluorine is attached to a carbon backbone. It is gaining interest as a potentially faster and less expensive option for monitoring PFAS impacts in soils, water and aqueous firefighting foam (AFFF). The test is distinct from routine PFAS analysis in that it reports a single result for a sample, representing the sum of fluorine arising from all organic fluorine substances measured, rather than individual results for different PFAS substances.

Combustion Ion Chromatography (CIC) is a leading technology for a widely available, high throughput, low cost approach to TOF analysis. CIC has a long history of application to organohalide analysis for chloride, bromide and iodide species. Recent advances have made it amenable to organofluoride species as well, with detection limits relevant for levels commonly encountered in environmental samples. These range from single digit ppb levels for most waters to a few tens of ppb for soils to high ppb or low ppm levels for AFFF.

We have been offering TOF-CIC analysis since mid-2020 and have learned much about the method and the equipment in that time. While the term TOF is widely used, it is actually a Total Extractable Organofluorine analysis because of the sample processing that is required prior to analysis. Our studies to determine how efficient these procedures are at extracting all PFAS from a sample have indicated some variability in extraction efficiency related to soil type and specific PFAS. Water and dilute AFFF appear to have consistently higher efficiencies than soils. We are also learning how to recognize when samples are impacted by organofluorine sources other than common PFAS. This talk will provide an overview of our findings in these and other areas for application of the method.