Chasing PFAS in Leachate: Key Factors That Shape Analytical Performance

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

Prepared by T. Liden1, K. Schug2, K. Xia1, V. Johnson1, O. Shrestha1, R. Marfil-Vega1, E. Wang1
1 - Shimadzu Scientific Instruments, 7102 Riverwood Drive, Columbia, MD, 21046, United States
2 - University of Texas at Alrington, 701 S Nedderman Dr, Arlington, Texas, 76019, United States


Contact Information: [email protected]; 682-326-1267

ABSTRACT

Consistent PFAS data quality in landfill leachate is difficult to achieve despite the availability of validated analytical methods. Its extreme chemical heterogeneity, which varies by location and over time, introduces substantial analytical challenges. While EPA Method 1633A provides a validated framework for PFAS analysis in leachate, analytical performance remains strongly influenced by sample preparation efficiency, chromatographic behavior, and mass spectrometric source conditions. This study evaluates key contributors to sensitivity, robustness, and reproducibility for LC–MS/MS PFAS analysis in landfill leachate, with emphasis on performance factors beyond procedural compliance.

Authentic landfill leachate composite samples were prepared in accordance with EPA Method 1633A. Sample-preparation performance was evaluated by comparing commercially available weak anion-exchange (WAX) SPE cartridges, using extracted isotopically labeled internal standards to assess recovery and variability across PFAS chemistries. Chromatographic performance was examined using multiple C18 columns of identical dimensions under consistent gradient conditions. Mass spectrometric source parameters were systematically varied to evaluate their influence on signal intensity and background noise.

Results demonstrate that sample preparation, chromatography, and source conditions each strongly influence method performance of PFAS in leachate. SPE cartridge selection produced substantial differences in recovery and reproducibility across fluorotelomer sulfonates, perfluoroalkyl carboxylates, sulfonates, and PFAA precursor compounds, with some internal standard recoveries increasing from ~40% to ~100% while maintaining or improving precision. Chromatographic evaluation revealed measurable differences in peak shape, response, and resolution among nominally identical C18 columns. Source parameter screening revealed compound-dependent response trends, with enhanced aerosol formation improving short-chain PFAS sensitivity, whereas increased desolvation temperatures disproportionately benefited longer-chain and PFAA precursor compounds. These findings demonstrate that deliberate optimization of analytical conditions is essential for generating reliable PFAS data in highly complex environmental matrices.