Application of a Quantitative Non-targeted Analysis Workflow to Characterize PFAS in Environmental Waters

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Risk Assessment

Background:

• Non-targeted analysis (NTA) detects novel chemicals but lacks quantitative data for risk assessment.
• Quantitative NTA (qNTA) using surrogate chemicals offers a path to estimate concentrations of detected unknowns.
• Previous work established qNTA performance metrics and compared approaches across different matrices.

Purpose of the Study:

• To apply and validate an integrated qNTA workflow for assessing per- and polyfluoroalkyl substances (PFAS) in environmental waters.
• To demonstrate the utility of qNTA for estimating concentrations and uncertainties of a wide range of PFAS.
• To evaluate the reliability and accuracy of the qNTA approach in real-world contaminated water samples.

Main Methods:

• Developed an integrated qNTA workflow using 37 commercially available surrogate chemicals for calibration.
• Employed a naïve bounded response factor approach for qNTA estimation.
• Validated the workflow using paired NTA and targeted analysis data for 16 PFAS (129 data points).

Main Results:

• Achieved median accuracy within a factor of 2 and an uncertainty range of 12-fold for paired NTA and targeted analysis.
• Reported an overall reliability of 85%, with lower-than-expected values suggesting potential surrogate selection issues.
• Generated concentration and uncertainty estimates for 210 individual PFAS, with some reaching parts-per-billion levels.

Conclusions:

• The validated qNTA workflow provides valuable quantitative estimates for chemicals detected by NTA.
• This approach is essential for comprehensive exposure, hazard, and risk assessments of total PFAS burden in watersheds.
• Quantitative data from qNTA supports informed environmental management decisions regarding PFAS contamination.