Evaluation of PFAS extraction and analysis methods for biosolids

Area of Science:

• Environmental Chemistry
• Analytical Chemistry

Background:

• Per- and polyfluoroalkyl substances (PFAS) are environmental contaminants of growing concern.
• Biosolids, a wastewater treatment byproduct, are increasingly scrutinized for PFAS content due to their application in soil health improvement.
• Accurate analytical methods are crucial for quantifying PFAS in complex matrices like biosolids.

Purpose of the Study:

• To compare the performance of three analytical methods for per- and polyfluoroalkyl substances (PFAS) quantitation in biosolids.
• To evaluate solvent extraction, clean-up techniques, and injection solvents for PFAS analysis.
• To identify the most effective and cost-efficient method for PFAS determination in diverse biosolids.

Main Methods:

• Three biosolids with different properties were analyzed using three methods: modified methanolic extraction (ME-P), U.S. EPA 1633, and Quick Easy Cheap Effective Rugged and Safe (QuEChERS).
• Method performance was assessed based on instrument precision, limit of quantitation (LOQ), and extraction recoveries.
• Key parameters evaluated included solvent extraction, clean-up efficiency, and injection solvent effects on emulsification and peak shape.

Main Results:

• The ME-P and U.S. EPA 1633 methods yielded similar PFAS concentrations and recoveries.
• QuEChERS method performed poorly for PFAS quantitation in biosolids.
• ME-P demonstrated superior cost-effectiveness, extraction efficiency, and fewer operational steps compared to other methods.

Conclusions:

• The modified methanolic extraction with isopropanol (ME-P) is a highly effective and cost-efficient method for PFAS quantitation in biosolids.
• This method offers advantages in extraction efficiency and operational simplicity for analyzing PFAS in soil amendments.
• Further validation of ME-P can support environmental monitoring and risk assessment of PFAS in biosolids.