LC-MS/MS Analysis of Legacy and Emerging Perfluoroalkyl Substances (PFAS) in Environmental Water Samples Following SPE Enrichment

Challenges and Opportunities for Solid Phase Extraction
Oral Presentation

Prepared by , K. Rosnack, D. Stevens, J. Romano

Contact Information: Kari_Organtini@waters.com; 508-482-3242


ABSTRACT

PFAS are common persistent environmental contaminants used in the production of many consumer products. They are used as surfactants and for nonstick, stain, and water resistance coatings. PFAS are also a major components of fire fighting foams used for suppression of fuel fires. Global use of these compounds over decades has led to their release into the environment. PFAS are classified as persistent organic pollutants.

Currently, there are no legal regulations pertaining to PFAS monitoring, although PFOS and PFOA are included in many advisory guidelines. The US EPA has established a drinking water health advisory level of 70 ppt (ng/L) for total levels of PFOS and PFOA. In Europe, the Water Framework Directive and Drinking Water Directive have set minimum quality standards of PFOS and PFOA which range from the ppb to sub-ppt levels. Such examples of monitoring guidelines demonstrate the need for highly sensitive analytical measurements to detect PFAS.

Typically to reach sub-ppt levels, sample enrichment prior to LC-MS/MS analysis is required. Sample prep similar to that described in ISO 25101 method is typically applied for enrichment of PFAS in water samples. It will be demonstrated that ISO 25101 can be expanded to a wide range of PFAS compounds. Data provided will demonstrate the use of a weak anion exchange SPE cartridge for the analysis of approximately 40 legacy and emerging PFAS compounds, including GenX. The method was assessed using surface, ground, influent and effluent water. The extended method was found to be robust in all types of matrices tested with detection limits in the low to sub ppt range, making this method in compliance with the guidelines set in both the US and EU. Percent recoveries were within the prescribed range of 70 - 130 % and method repeatability was assessed with %RSDs below 15% over six replicates.