Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Leachate by EPA Method 1633A Using LC-MS/MS

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

Prepared by T. Liden1, K. Schug2, R. Marfil-Vega1, O. Shrestha1, R. English1, T. Matsubara1, E. Wang1
1 - Shimadzu Scientific Instruments, 10330 Old Columbia Rd, Columbia, MD, 21046, United States
2 - University of Texas at Arlington, , , United States


Contact Information: [email protected]; 410-910-0884

ABSTRACT

A recent EPA study detected PFAS in over 95% of leachate samples from more than 200 landfills across the U.S., with concentrations reaching up to 14,000 ppt and identifying 63 different compounds. Despite growing concerns and some state-level regulations, there are currently no federal mandates for monitoring or treating landfill leachate, underscoring the need for nationwide effluent guidelines and pretreatment standards.
EPA Method 1633A is the only validated multi-laboratory approach for PFAS detection in leachate. The 40 PFAS analytes and 31 internal standards, were chromatographically separated within 14 minutes using a Shim-pack Scepter C18-120 column (50 × 2.1 mm, 3 µm) and gradient elution. Mobile phases consisted of 2 mM ammonium acetate in water and acetonitrile, with a flow rate of 0.4 mL/min. A Shimadzu Nexcol PFAS Delay column minimized system PFAS interference, ensuring accurate quantitation.
Calibration curves for the 40 analytes ranged from 0.8 to 250 ng/mL for PFBA, with precision maintained below 20% relative standard error (RSE) across five replicates. Calibration verification (CCV), performed every 10 of 143 injections, showed recoveries within 70–130% and variations below 15% RSD. Spiked and unspiked leachate samples from the southern U.S. were analyzed alongside laboratory control samples (LCS) and a method blank. LCS results demonstrated excellent quantitation accuracy, with recovery rates meeting EPA criteria (70–130%). No quantifiable PFAS target compounds were found in the method blank, demonstrating the effectiveness of the system and delay column in minimizing environmental PFAS contamination from the laboratory and consumables.
Detected PFAS in unspiked leachate included PFBA, PFBS, PFHxA, PFOA, PFOS, and others. These findings highlight the widespread prevalence of PFAS in landfill leachate. In this presentation we will shared a detailed discussion of the method validation results.