Investigation of pH-dependent extraction methods for PFAS in (fluoropolymer-based) consumer products: A comparative...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Materials Science

Background:

• Per- and polyfluoroalkyl substances (PFAS) are prevalent in consumer products, posing environmental and health concerns.
• Accurate quantification of PFAS is challenging due to diverse chemical structures and matrices.
• Existing methods may not fully capture all PFAS, including polymeric forms.

Purpose of the Study:

• To develop and validate a hydrolysis-based extraction method for PFAS in consumer products.
• To compare this method with existing sum parameter analyses for fluorine quantification.
• To improve the mass balance assessment of PFAS in manufactured goods.

Main Methods:

• Developed a hydrolysis-based extraction method to quantify "hydrolyzable organically bound fluorine" (HOF).
• Applied the method to 39 consumer products across four categories (textiles, paper, carpeting, bakeware).
• Measured total fluorine (TF) and extractable organically bound fluorine (EOF) using combustion ion chromatography (CIC).
• Compared results with "total hydrolyzable precursor" (THP) assay (GC-MS) and targeted LC-MS/MS analysis.
• Evaluated extraction efficiency using synthesized fluorotelomer polyacrylate reference compounds.

Main Results:

• The HOF method detected significant levels of hydrolyzable organofluorine (0.03–76.3 μg/g) in consumer products.
• Most extractable organically bound fluorine (EOF) values were lower than HOF, indicating the presence of non-extractable forms.
• Targeted LC-MS/MS analysis yielded substantially lower sum amounts of specific PFAS compared to sum parameter methods.
• Recovery rates for SFP model compounds varied, suggesting method-specific efficiencies for different PFAS types.

Conclusions:

• The developed hydrolysis-based extraction method provides a more comprehensive assessment of PFAS, including polymeric forms.
• This method enhances the accuracy of fluorine mass balance calculations in consumer products.
• Further refinement is needed to optimize recovery and address the complexity of PFAS in diverse matrices.