Gonda Nicholas, Zhang Chuhui, Tepedelen Dylan, Smith Adam, Schaefer Charles, Higgins Christopher P
Department of Civil and Environmental Engineering, Colorado School of Mines, Golden, CO, 80401, USA.
Department of Chemistry, Colorado School of Mines, Golden, CO, 80401, USA.
Anal Bioanal Chem. 2024 Dec;416(29):6879-6892. doi: 10.1007/s00216-024-05585-2. Epub 2024 Oct 16.
Quantitatively assessing all per- and poly fluoroalkyl substances (PFASs) in an environmental sample, particularly soils impacted by aqueous film forming foams (AFFFs), has proven to be a challenge. To make such an assessment, a comprehensive sample processing procedure and analytical tool must be used. However, doubts remain whether current analytical tools such as high-resolution mass spectrometry (HRMS) with targeted quantitation and semi-quantitative analysis of suspects (Semi-Q HRMS) or total organic fluorine (TOF) are capable of accurately quantifying all non-polymeric PFASs in a sample. Further, current comprehensive soil PFAS HRMS methods are incompatible with TOF, preventing direct comparisons of the approaches. To enable direct comparisons, a soil sample processing procedure that is comprehensive as well as compatible with multiple analytical tools is needed. In this study, we assessed the performance of a previously developed soil PFAS method, EPA Method 1633, and a hybrid solid phase extraction (SPE)-based method for characterizing AFFF-impacted soil composites while maintaining compatibility with multiple analytical tools (i.e., Semi-Q HRMS and TOF). Comparative results for AFFF-impacted soil composites indicate analysis via EPA Method 1633 (as compared to the novel hybrid method) results in maybe up to 75% of the PFAS mass being missed by only analyzing for compounds listed in EPA Method 1633. Simply expanding the EPA Method 1633 analyte list was insufficient to account for the missing mass: up to 69% of the PFAS mass was still missed because of EPA Method 1633's extraction and cleanup bias. Additionally, the novel method developed offers a more comprehensive analysis with minimal reductions to sensitivity when compared to those reported in EPA Method 1633, with limits of quantification ranging from 0.12 to 2.4 ng/g as compared to 0.16-4.0 ng/g, respectively. For these reasons, an alternative hybrid SPE-based method is proposed for comprehensive evaluation of PFASs in AFFF-impacted soils.
对环境样品，尤其是受水成膜泡沫（AFFF）影响的土壤中的所有全氟和多氟烷基物质（PFAS）进行定量评估已被证明是一项挑战。要进行这样的评估，必须使用全面的样品处理程序和分析工具。然而，目前的分析工具，如具有目标定量和可疑物半定量分析（Semi-Q HRMS）的高分辨率质谱（HRMS）或总有机氟（TOF），是否能够准确量化样品中的所有非聚合PFAS，仍存在疑问。此外，目前全面的土壤PFAS HRMS方法与TOF不兼容，无法直接比较这些方法。为了能够进行直接比较，需要一种既全面又与多种分析工具兼容的土壤样品处理程序。在本研究中，我们评估了先前开发的土壤PFAS方法EPA方法1633，以及一种基于混合固相萃取（SPE）的方法在表征受AFFF影响的土壤复合物时的性能，同时保持与多种分析工具（即Semi-Q HRMS和TOF）的兼容性。受AFFF影响的土壤复合物的比较结果表明，通过EPA方法1633进行分析（与新型混合方法相比），仅分析EPA方法1633中列出的化合物可能会遗漏高达75%的PFAS质量。仅仅扩大EPA方法1633的分析物清单不足以解释遗漏的质量：由于EPA方法1633的萃取和净化偏差，仍有高达69%的PFAS质量被遗漏。此外，与EPA方法1633中报告的相比，开发的新方法提供了更全面的分析，灵敏度降低最小，定量限分别为0.12至2.4 ng/g和0.16 - 4.0 ng/g。基于这些原因，提出了一种基于混合SPE的替代方法，用于全面评估受AFFF影响的土壤中的PFAS。
