Enhanced full-process method for the quantitative analysis of PFAS in sludge: Robust extraction and matrix
Song Li1, Jingwei Yan2, Wanying Zhai3
1Hubei Key Laboratory of Multi-media Pollution Cooperative Control in Yangtze Basin, School of Environmental Science & Engineering, Huazhong University of Science and Technology (HUST), 1037 Luoyu Road, Wuhan, Hubei, 430074, China; Ecological Environment Monitoring and Scientific Research Center, Ecology and Environment Supervision and Administration Bureau of Yangze River Valley, Ministry of Ecology and Environment, Wuhan, Hubei 430015, China.
A new method efficiently extracts and quantifies 48 per- and polyfluoroalkyl substances (PFAS) from sewage sludge. This robust technique improves accuracy and expands the scope of PFAS analysis in complex environmental samples.
Area of Science:
- Environmental Chemistry
- Analytical Chemistry
Background:
- Accurate quantification of per- and polyfluoroalkyl substances (PFAS) in complex matrices like sewage sludge remains a significant analytical challenge.
- Existing methods may lack efficiency, robustness, or the ability to detect a wide range of PFAS species.
Purpose of the Study:
- To develop and validate a rigorous, robust, and efficient method for extracting and quantifying a broad spectrum of PFAS (48 species) from sewage sludge.
- To compare the performance of the developed method against established extraction techniques.
Main Methods:
- Optimization of key parameters including liquid-solid ratio, extraction solvent composition (methanol ammonia hydroxide), oscillation conditions, and pH adjustment prior to solid-phase extraction.
- Validation of the method through recovery studies and relative standard deviation assessments.
- Investigation of matrix effects using different sludge types (anaerobically digested vs. waste activated) and mitigation strategies.
Main Results:
- Achieved acceptable recovery (50%-125%) for most target PFAS (45 of 48) with low relative standard deviation (≤ 16.84%).
- The proposed method demonstrated a 17.3%-27.6% increase in total extracted PFAS concentration compared to ASTM D2216, HJ 1334-2023, and EPA 1633A.
- Identified 3 additional PFAS types, enhancing analytical scope and accuracy. Matrix effects were lower in anaerobically digested sludge, suggesting unstable organic matter is a key factor.
- Mitigation strategies like reduced injection volume and sample dilution effectively managed matrix effects.
Conclusions:
- The developed method is reliable and efficient for the accurate quantification of a wide range of PFAS in complex sludge matrices.
- The findings provide a valuable tool for enhanced environmental monitoring of PFAS contamination.
- Understanding matrix effects is crucial for accurate PFAS analysis in environmental samples.
