Sampling Recommendations for PFAS to Maximize Data Quality

Importance of the Topic

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants found in water, soil and consumer products. Their chemical stability and widespread use in firefighting foams, textiles and packaging make reliable detection essential for assessing environmental and human health risks. Proper sampling is the foundation for accurate PFAS analysis and prevents false positives or loss of analytes due to contamination or adsorption.

Objectives and Study Overview

This application note from ALS Czech Republic outlines optimized procedures for collecting, storing and transporting PFAS samples to ensure data quality. It reviews container materials, sampling volumes, preservation methods and transport conditions to minimize cross-contamination and analyte degradation before LC-MS analysis.

Methodology and Used Instrumentation

The study recommends using PFAS-free sampling containers tested by ALS or pre-tested HDPE or polypropylene bottles. Key steps include:

• Water sampling: fill 125–250 mL bottles (depending on detection limits) to the brim and seal tightly.
• Soil sampling: collect 50 g into PFAS-free containers or bags.
• Single-use nitrile gloves and PFAS-free tools to avoid contamination.
• Refrigerate samples at 2–5 °C and deliver to the lab within 48 hours.

Analyses are performed using highly sensitive liquid chromatography–mass spectrometry (LC-MS) methods accredited by ALS.

Main Findings and Discussion

Comparative assessments of container materials show that fluorinated plastics (PTFE, PVDF, FEP) and glass can adsorb PFAS compounds, leading to analyte loss or background contamination. HDPE and PP bottles with pre-testing offer the best balance of chemical inertness and availability. Proper washing with methanol:water (1:1) further reduces background PFAS levels.

Benefits and Practical Applications

Implementing these guidelines enables environmental and industrial laboratories to:

• Obtain reproducible PFAS concentrations in water and soil.
• Comply with ISO 21675 and EPA methods (1633, 537.1) for PFAS sampling.
• Reduce sample rejections and retests due to contamination issues.

Future Trends and Potential Applications

Emerging directions include development of field-deployable PFAS sampling kits, novel inert polymer containers, sensor-based contamination checks and harmonized global sampling standards. Ongoing research may integrate on-site pre-concentration and rapid screening to accelerate environmental monitoring.

Conclusion

Accurate PFAS analysis relies on rigorous sampling protocols that eliminate sources of contamination and analyte loss. Adopting ALS-validated containers, standardized volumes, proper preservation and timely transport ensures high-quality data for environmental assessments and regulatory compliance.

References

• ISO 21675:2019: Water quality—Sampling for PFAS analysis.
• EPA Draft Method 1633: Analysis of PFAS by LC-MS/MS.
• EPA Method 537.1: Determination of PFAS in drinking water.