Simultaneous Analysis of Ultrashort- to Long-Chain PFAS in Multisalinity Aquatic Systems: Methodology, Spatial
Wei Ma1, Fei Li2, Yawen Tian1
1Key Laboratory of Environmental Health Impact Assessment for Emerging Contaminants, Ministry of Ecology and Environment of the People's Republic of China, School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Environmental Science & Technology
|November 17, 2025
Summary
Ultrashort-chain per- and polyfluoroalkyl substances (PFAS) are mobile environmental contaminants. A new method quantifies 60 PFAS, finding trifluoroacetic acid (TFA) is dominant, but C7 HFPO-TA is increasing near industrial sites.
Area of Science:
- Environmental Chemistry
- Analytical Chemistry
- Environmental Science
Background:
- Ultrashort-chain PFAS are increasingly detected and mobile in the environment.
- Routine analysis of diverse PFAS, including ultrashort-chain variants, is challenging.
- Understanding PFAS distribution and hazard is crucial for environmental management.
Purpose of the Study:
- To develop and validate a multidimensional liquid chromatography-tandem mass spectrometry method for quantifying 60 PFAS.
- To analyze PFAS concentrations in surface waters along a salinity gradient.
- To assess the environmental hazard of detected PFAS and prioritize pollutants.
Main Methods:
- Established a 2D-LC-MS/MS platform for simultaneous quantification of 60 PFAS.
- Utilized large-volume direct injection for sensitive detection (≤1 ng/L LOQ).
- Applied an Environmental Hazard Prioritization Index (EHPI) using predictive models.
Main Results:
- Trifluoroacetic acid (TFA) was the dominant PFAS, comprising 87-99% of total PFAS.
- Median TFA concentrations decreased downstream of a fluorochemical industrial park in 2024.
- Perfluoro-2,5-dimethyl-3,6-dioxo-heptanoic acid (C7 HFPO-TA) concentrations increased significantly downstream.
- TFA and C7 HFPO-TA were identified as the highest priority chemicals based on EHPI.
Conclusions:
- The developed method enables simultaneous quantification of ultrashort- to long-chain PFAS.
- PFAS profiles vary spatially, with industrial discharge impacting downstream concentrations.
- Urgent monitoring and regulatory action are needed for high-priority PFAS like TFA and C7 HFPO-TA.
