Analysis of Per- and Polyfluoroalkyl Substances in Drinking Water Using EPA Methods 533 and 537.1 with Semi-Automated Solid Phase Extraction (EZPFC™)

Polyfluoroalkyl Substances (PFAS) in the Environment
Poster Presentation

Prepared by , T. Hall

Contact Information: raddink@fms-inc.com; 617-393-2396


ABSTRACT

Per- and polyfluoralkyl substances (PFAS) are compounds that are largely comprised of or contain a perfluorinated or polyfluorinated carbon chain moiety such as F(CF2)n- or F(CF2)n-(C2H4)n. PFAS are widely used in consumer and industrial applications. There has been increasing concern over the levels of PFAS such as PFOS and PFOA (perfluorooctanoic acid) in the global environment and their fate and possible adverse effects.

In the US recent EPA methods 533 and 537.1 have been released for analyzing PFAS in drinking water samples. To meet demands for a low-cost method that requires less financial investment than automated systems, we developed a simple semi-automated system which is fast, inexpensive and yields high quality data.

Method for 537.1: Six 250 mL water samples were spiked with 2 or 50 ppt PFAS standards. Sample bottles were loaded onto system and rinse bottles were filled with 7.5 mL water. SDVB cartridges were installed (six positions) and vacuum was turned on. Cartridges were conditioned with 15 mL methanol (soak 1min) and 18 mL water (same). Samples loaded across the cartridges under vacuum (20-25 min, ~8inch Hg). Sample bottles were rinsed automatically with nitrogen with 7.5 mL water twice which was loaded across cartridges (dry 5min).

Rinse bottles with 4 mL methanol were used to rinse sample bottles and rinses were loaded across the cartridges (twice, 1 min soak, 8 mL methanol total). Eluent was collected for analysis into Direct-to-GC Vial Collection Vessels. Samples were reduced in volume with automated concentration; analysis with LC/MS.

A total of ~ 30 PFAS were analyzed and recoveries were well within the acceptance windows of 70-130% for both methods. Data showed good reproducibility. The semi-automated system is a good choice compared to traditional, time-consuming, inconsistent and expensive liquid/liquid extractions. Native background contributions from the system are low: non-detect to 0.15 ng/L.